diff --git a/crates/gpui2/src/executor.rs b/crates/gpui2/src/executor.rs
index 28d4b6d117..6bfd9ce15a 100644
--- a/crates/gpui2/src/executor.rs
+++ b/crates/gpui2/src/executor.rs
@@ -163,6 +163,10 @@ impl Executor {
         future: impl Future<Output = R>,
     ) -> Result<R, impl Future<Output = R>> {
         let mut future = Box::pin(future);
+        if duration.is_zero() {
+            return Err(future);
+        }
+
         let timeout = {
             let future = &mut future;
             async {
diff --git a/crates/language2/src/buffer_tests.rs b/crates/language2/src/buffer_tests.rs
index c5790de881..fc60f31018 100644
--- a/crates/language2/src/buffer_tests.rs
+++ b/crates/language2/src/buffer_tests.rs
@@ -311,134 +311,134 @@ async fn test_normalize_whitespace(cx: &mut gpui2::TestAppContext) {
     });
 }
 
-// #[gpui2::test]
-// async fn test_reparse(cx: &mut gpui2::TestAppContext) {
-//     let text = "fn a() {}";
-//     let buffer = cx.entity(|cx| {
-//         Buffer::new(0, cx.entity_id().as_u64(), text).with_language(Arc::new(rust_lang()), cx)
-//     });
+#[gpui2::test]
+async fn test_reparse(cx: &mut gpui2::TestAppContext) {
+    let text = "fn a() {}";
+    let buffer = cx.entity(|cx| {
+        Buffer::new(0, cx.entity_id().as_u64(), text).with_language(Arc::new(rust_lang()), cx)
+    });
 
-//     // Wait for the initial text to parse
-//     cx.executor().run_until_parked();
-//     assert!(!buffer.update(cx, |buffer, _| buffer.is_parsing()));
-//     assert_eq!(
-//         get_tree_sexp(&buffer, cx),
-//         concat!(
-//             "(source_file (function_item name: (identifier) ",
-//             "parameters: (parameters) ",
-//             "body: (block)))"
-//         )
-//     );
+    // Wait for the initial text to parse
+    cx.executor().run_until_parked();
+    assert!(!buffer.update(cx, |buffer, _| buffer.is_parsing()));
+    assert_eq!(
+        get_tree_sexp(&buffer, cx),
+        concat!(
+            "(source_file (function_item name: (identifier) ",
+            "parameters: (parameters) ",
+            "body: (block)))"
+        )
+    );
 
-//     buffer.update(cx, |buffer, _| {
-//         buffer.set_sync_parse_timeout(Duration::ZERO)
-//     });
+    buffer.update(cx, |buffer, _| {
+        buffer.set_sync_parse_timeout(Duration::ZERO)
+    });
 
-//     // Perform some edits (add parameter and variable reference)
-//     // Parsing doesn't begin until the transaction is complete
-//     buffer.update(cx, |buf, cx| {
-//         buf.start_transaction();
+    // Perform some edits (add parameter and variable reference)
+    // Parsing doesn't begin until the transaction is complete
+    buffer.update(cx, |buf, cx| {
+        buf.start_transaction();
 
-//         let offset = buf.text().find(')').unwrap();
-//         buf.edit([(offset..offset, "b: C")], None, cx);
-//         assert!(!buf.is_parsing());
+        let offset = buf.text().find(')').unwrap();
+        buf.edit([(offset..offset, "b: C")], None, cx);
+        assert!(!buf.is_parsing());
 
-//         let offset = buf.text().find('}').unwrap();
-//         buf.edit([(offset..offset, " d; ")], None, cx);
-//         assert!(!buf.is_parsing());
+        let offset = buf.text().find('}').unwrap();
+        buf.edit([(offset..offset, " d; ")], None, cx);
+        assert!(!buf.is_parsing());
 
-//         buf.end_transaction(cx);
-//         assert_eq!(buf.text(), "fn a(b: C) { d; }");
-//         assert!(buf.is_parsing());
-//     });
-//     cx.executor().run_until_parked();
-//     assert!(!buffer.update(cx, |buffer, _| buffer.is_parsing()));
-//     assert_eq!(
-//         get_tree_sexp(&buffer, cx),
-//         concat!(
-//             "(source_file (function_item name: (identifier) ",
-//             "parameters: (parameters (parameter pattern: (identifier) type: (type_identifier))) ",
-//             "body: (block (expression_statement (identifier)))))"
-//         )
-//     );
+        buf.end_transaction(cx);
+        assert_eq!(buf.text(), "fn a(b: C) { d; }");
+        assert!(buf.is_parsing());
+    });
+    cx.executor().run_until_parked();
+    assert!(!buffer.update(cx, |buffer, _| buffer.is_parsing()));
+    assert_eq!(
+        get_tree_sexp(&buffer, cx),
+        concat!(
+            "(source_file (function_item name: (identifier) ",
+            "parameters: (parameters (parameter pattern: (identifier) type: (type_identifier))) ",
+            "body: (block (expression_statement (identifier)))))"
+        )
+    );
 
-//     // Perform a series of edits without waiting for the current parse to complete:
-//     // * turn identifier into a field expression
-//     // * turn field expression into a method call
-//     // * add a turbofish to the method call
-//     buffer.update(cx, |buf, cx| {
-//         let offset = buf.text().find(';').unwrap();
-//         buf.edit([(offset..offset, ".e")], None, cx);
-//         assert_eq!(buf.text(), "fn a(b: C) { d.e; }");
-//         assert!(buf.is_parsing());
-//     });
-//     buffer.update(cx, |buf, cx| {
-//         let offset = buf.text().find(';').unwrap();
-//         buf.edit([(offset..offset, "(f)")], None, cx);
-//         assert_eq!(buf.text(), "fn a(b: C) { d.e(f); }");
-//         assert!(buf.is_parsing());
-//     });
-//     buffer.update(cx, |buf, cx| {
-//         let offset = buf.text().find("(f)").unwrap();
-//         buf.edit([(offset..offset, "::<G>")], None, cx);
-//         assert_eq!(buf.text(), "fn a(b: C) { d.e::<G>(f); }");
-//         assert!(buf.is_parsing());
-//     });
-//     cx.executor().run_until_parked();
-//     assert_eq!(
-//         get_tree_sexp(&buffer, cx),
-//         concat!(
-//             "(source_file (function_item name: (identifier) ",
-//             "parameters: (parameters (parameter pattern: (identifier) type: (type_identifier))) ",
-//             "body: (block (expression_statement (call_expression ",
-//             "function: (generic_function ",
-//             "function: (field_expression value: (identifier) field: (field_identifier)) ",
-//             "type_arguments: (type_arguments (type_identifier))) ",
-//             "arguments: (arguments (identifier)))))))",
-//         )
-//     );
+    // Perform a series of edits without waiting for the current parse to complete:
+    // * turn identifier into a field expression
+    // * turn field expression into a method call
+    // * add a turbofish to the method call
+    buffer.update(cx, |buf, cx| {
+        let offset = buf.text().find(';').unwrap();
+        buf.edit([(offset..offset, ".e")], None, cx);
+        assert_eq!(buf.text(), "fn a(b: C) { d.e; }");
+        assert!(buf.is_parsing());
+    });
+    buffer.update(cx, |buf, cx| {
+        let offset = buf.text().find(';').unwrap();
+        buf.edit([(offset..offset, "(f)")], None, cx);
+        assert_eq!(buf.text(), "fn a(b: C) { d.e(f); }");
+        assert!(buf.is_parsing());
+    });
+    buffer.update(cx, |buf, cx| {
+        let offset = buf.text().find("(f)").unwrap();
+        buf.edit([(offset..offset, "::<G>")], None, cx);
+        assert_eq!(buf.text(), "fn a(b: C) { d.e::<G>(f); }");
+        assert!(buf.is_parsing());
+    });
+    cx.executor().run_until_parked();
+    assert_eq!(
+        get_tree_sexp(&buffer, cx),
+        concat!(
+            "(source_file (function_item name: (identifier) ",
+            "parameters: (parameters (parameter pattern: (identifier) type: (type_identifier))) ",
+            "body: (block (expression_statement (call_expression ",
+            "function: (generic_function ",
+            "function: (field_expression value: (identifier) field: (field_identifier)) ",
+            "type_arguments: (type_arguments (type_identifier))) ",
+            "arguments: (arguments (identifier)))))))",
+        )
+    );
 
-//     buffer.update(cx, |buf, cx| {
-//         buf.undo(cx);
-//         buf.undo(cx);
-//         buf.undo(cx);
-//         buf.undo(cx);
-//         assert_eq!(buf.text(), "fn a() {}");
-//         assert!(buf.is_parsing());
-//     });
+    buffer.update(cx, |buf, cx| {
+        buf.undo(cx);
+        buf.undo(cx);
+        buf.undo(cx);
+        buf.undo(cx);
+        assert_eq!(buf.text(), "fn a() {}");
+        assert!(buf.is_parsing());
+    });
 
-//     cx.executor().run_until_parked();
-//     assert_eq!(
-//         get_tree_sexp(&buffer, cx),
-//         concat!(
-//             "(source_file (function_item name: (identifier) ",
-//             "parameters: (parameters) ",
-//             "body: (block)))"
-//         )
-//     );
+    cx.executor().run_until_parked();
+    assert_eq!(
+        get_tree_sexp(&buffer, cx),
+        concat!(
+            "(source_file (function_item name: (identifier) ",
+            "parameters: (parameters) ",
+            "body: (block)))"
+        )
+    );
 
-//     buffer.update(cx, |buf, cx| {
-//         buf.redo(cx);
-//         buf.redo(cx);
-//         buf.redo(cx);
-//         buf.redo(cx);
-//         assert_eq!(buf.text(), "fn a(b: C) { d.e::<G>(f); }");
-//         assert!(buf.is_parsing());
-//     });
-//     cx.executor().run_until_parked();
-//     assert_eq!(
-//         get_tree_sexp(&buffer, cx),
-//         concat!(
-//             "(source_file (function_item name: (identifier) ",
-//             "parameters: (parameters (parameter pattern: (identifier) type: (type_identifier))) ",
-//             "body: (block (expression_statement (call_expression ",
-//             "function: (generic_function ",
-//             "function: (field_expression value: (identifier) field: (field_identifier)) ",
-//             "type_arguments: (type_arguments (type_identifier))) ",
-//             "arguments: (arguments (identifier)))))))",
-//         )
-//     );
-// }
+    buffer.update(cx, |buf, cx| {
+        buf.redo(cx);
+        buf.redo(cx);
+        buf.redo(cx);
+        buf.redo(cx);
+        assert_eq!(buf.text(), "fn a(b: C) { d.e::<G>(f); }");
+        assert!(buf.is_parsing());
+    });
+    cx.executor().run_until_parked();
+    assert_eq!(
+        get_tree_sexp(&buffer, cx),
+        concat!(
+            "(source_file (function_item name: (identifier) ",
+            "parameters: (parameters (parameter pattern: (identifier) type: (type_identifier))) ",
+            "body: (block (expression_statement (call_expression ",
+            "function: (generic_function ",
+            "function: (field_expression value: (identifier) field: (field_identifier)) ",
+            "type_arguments: (type_arguments (type_identifier))) ",
+            "arguments: (arguments (identifier)))))))",
+        )
+    );
+}
 
 #[gpui2::test]
 async fn test_resetting_language(cx: &mut gpui2::TestAppContext) {
diff --git a/crates/language2/src/highlight_map.rs b/crates/language2/src/highlight_map.rs
index 8953fa571b..b394d0446e 100644
--- a/crates/language2/src/highlight_map.rs
+++ b/crates/language2/src/highlight_map.rs
@@ -76,36 +76,36 @@ impl Default for HighlightId {
     }
 }
 
-// #[cfg(test)]
-// mod tests {
-//     use super::*;
-//     use gpui2::color::Color;
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use gpui2::rgba;
 
-//     #[test]
-//     fn test_highlight_map() {
-//         let theme = SyntaxTheme::new(
-//             [
-//                 ("function", Color::from_u32(0x100000ff)),
-//                 ("function.method", Color::from_u32(0x200000ff)),
-//                 ("function.async", Color::from_u32(0x300000ff)),
-//                 ("variable.builtin.self.rust", Color::from_u32(0x400000ff)),
-//                 ("variable.builtin", Color::from_u32(0x500000ff)),
-//                 ("variable", Color::from_u32(0x600000ff)),
-//             ]
-//             .iter()
-//             .map(|(name, color)| (name.to_string(), (*color).into()))
-//             .collect(),
-//         );
+    #[test]
+    fn test_highlight_map() {
+        let theme = SyntaxTheme {
+            highlights: [
+                ("function", rgba(0x100000ff)),
+                ("function.method", rgba(0x200000ff)),
+                ("function.async", rgba(0x300000ff)),
+                ("variable.builtin.self.rust", rgba(0x400000ff)),
+                ("variable.builtin", rgba(0x500000ff)),
+                ("variable", rgba(0x600000ff)),
+            ]
+            .iter()
+            .map(|(name, color)| (name.to_string(), (*color).into()))
+            .collect(),
+        };
 
-//         let capture_names = &[
-//             "function.special".to_string(),
-//             "function.async.rust".to_string(),
-//             "variable.builtin.self".to_string(),
-//         ];
+        let capture_names = &[
+            "function.special".to_string(),
+            "function.async.rust".to_string(),
+            "variable.builtin.self".to_string(),
+        ];
 
-//         let map = HighlightMap::new(capture_names, &theme);
-//         assert_eq!(map.get(0).name(&theme), Some("function"));
-//         assert_eq!(map.get(1).name(&theme), Some("function.async"));
-//         assert_eq!(map.get(2).name(&theme), Some("variable.builtin"));
-//     }
-// }
+        let map = HighlightMap::new(capture_names, &theme);
+        assert_eq!(map.get(0).name(&theme), Some("function"));
+        assert_eq!(map.get(1).name(&theme), Some("function.async"));
+        assert_eq!(map.get(2).name(&theme), Some("variable.builtin"));
+    }
+}
diff --git a/crates/language2/src/syntax_map/syntax_map_tests.rs b/crates/language2/src/syntax_map/syntax_map_tests.rs
index 55b0b8b778..732ed7e936 100644
--- a/crates/language2/src/syntax_map/syntax_map_tests.rs
+++ b/crates/language2/src/syntax_map/syntax_map_tests.rs
@@ -1,1323 +1,1323 @@
-// use super::*;
-// use crate::LanguageConfig;
-// use rand::rngs::StdRng;
-// use std::{env, ops::Range, sync::Arc};
-// use text::Buffer;
-// use tree_sitter::Node;
-// use unindent::Unindent as _;
-// use util::test::marked_text_ranges;
-
-// #[test]
-// fn test_splice_included_ranges() {
-//     let ranges = vec![ts_range(20..30), ts_range(50..60), ts_range(80..90)];
-
-//     let (new_ranges, change) = splice_included_ranges(
-//         ranges.clone(),
-//         &[54..56, 58..68],
-//         &[ts_range(50..54), ts_range(59..67)],
-//     );
-//     assert_eq!(
-//         new_ranges,
-//         &[
-//             ts_range(20..30),
-//             ts_range(50..54),
-//             ts_range(59..67),
-//             ts_range(80..90),
-//         ]
-//     );
-//     assert_eq!(change, 1..3);
-
-//     let (new_ranges, change) = splice_included_ranges(ranges.clone(), &[70..71, 91..100], &[]);
-//     assert_eq!(
-//         new_ranges,
-//         &[ts_range(20..30), ts_range(50..60), ts_range(80..90)]
-//     );
-//     assert_eq!(change, 2..3);
-
-//     let (new_ranges, change) =
-//         splice_included_ranges(ranges.clone(), &[], &[ts_range(0..2), ts_range(70..75)]);
-//     assert_eq!(
-//         new_ranges,
-//         &[
-//             ts_range(0..2),
-//             ts_range(20..30),
-//             ts_range(50..60),
-//             ts_range(70..75),
-//             ts_range(80..90)
-//         ]
-//     );
-//     assert_eq!(change, 0..4);
-
-//     let (new_ranges, change) =
-//         splice_included_ranges(ranges.clone(), &[30..50], &[ts_range(25..55)]);
-//     assert_eq!(new_ranges, &[ts_range(25..55), ts_range(80..90)]);
-//     assert_eq!(change, 0..1);
-
-//     // does not create overlapping ranges
-//     let (new_ranges, change) =
-//         splice_included_ranges(ranges.clone(), &[0..18], &[ts_range(20..32)]);
-//     assert_eq!(
-//         new_ranges,
-//         &[ts_range(20..32), ts_range(50..60), ts_range(80..90)]
-//     );
-//     assert_eq!(change, 0..1);
-
-//     fn ts_range(range: Range<usize>) -> tree_sitter::Range {
-//         tree_sitter::Range {
-//             start_byte: range.start,
-//             start_point: tree_sitter::Point {
-//                 row: 0,
-//                 column: range.start,
-//             },
-//             end_byte: range.end,
-//             end_point: tree_sitter::Point {
-//                 row: 0,
-//                 column: range.end,
-//             },
-//         }
-//     }
-// }
-
-// #[gpui::test]
-// fn test_syntax_map_layers_for_range() {
-//     let registry = Arc::new(LanguageRegistry::test());
-//     let language = Arc::new(rust_lang());
-//     registry.add(language.clone());
-
-//     let mut buffer = Buffer::new(
-//         0,
-//         0,
-//         r#"
-//             fn a() {
-//                 assert_eq!(
-//                     b(vec![C {}]),
-//                     vec![d.e],
-//                 );
-//                 println!("{}", f(|_| true));
-//             }
-//         "#
-//         .unindent(),
-//     );
-
-//     let mut syntax_map = SyntaxMap::new();
-//     syntax_map.set_language_registry(registry.clone());
-//     syntax_map.reparse(language.clone(), &buffer);
-
-//     assert_layers_for_range(
-//         &syntax_map,
-//         &buffer,
-//         Point::new(2, 0)..Point::new(2, 0),
-//         &[
-//             "...(function_item ... (block (expression_statement (macro_invocation...",
-//             "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
-//         ],
-//     );
-//     assert_layers_for_range(
-//         &syntax_map,
-//         &buffer,
-//         Point::new(2, 14)..Point::new(2, 16),
-//         &[
-//             "...(function_item ...",
-//             "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
-//             "...(array_expression (struct_expression ...",
-//         ],
-//     );
-//     assert_layers_for_range(
-//         &syntax_map,
-//         &buffer,
-//         Point::new(3, 14)..Point::new(3, 16),
-//         &[
-//             "...(function_item ...",
-//             "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
-//             "...(array_expression (field_expression ...",
-//         ],
-//     );
-//     assert_layers_for_range(
-//         &syntax_map,
-//         &buffer,
-//         Point::new(5, 12)..Point::new(5, 16),
-//         &[
-//             "...(function_item ...",
-//             "...(call_expression ... (arguments (closure_expression ...",
-//         ],
-//     );
-
-//     // Replace a vec! macro invocation with a plain slice, removing a syntactic layer.
-//     let macro_name_range = range_for_text(&buffer, "vec!");
-//     buffer.edit([(macro_name_range, "&")]);
-//     syntax_map.interpolate(&buffer);
-//     syntax_map.reparse(language.clone(), &buffer);
-
-//     assert_layers_for_range(
-//             &syntax_map,
-//             &buffer,
-//             Point::new(2, 14)..Point::new(2, 16),
-//             &[
-//                 "...(function_item ...",
-//                 "...(tuple_expression (call_expression ... arguments: (arguments (reference_expression value: (array_expression...",
-//             ],
-//         );
-
-//     // Put the vec! macro back, adding back the syntactic layer.
-//     buffer.undo();
-//     syntax_map.interpolate(&buffer);
-//     syntax_map.reparse(language.clone(), &buffer);
-
-//     assert_layers_for_range(
-//         &syntax_map,
-//         &buffer,
-//         Point::new(2, 14)..Point::new(2, 16),
-//         &[
-//             "...(function_item ...",
-//             "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
-//             "...(array_expression (struct_expression ...",
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_dynamic_language_injection() {
-//     let registry = Arc::new(LanguageRegistry::test());
-//     let markdown = Arc::new(markdown_lang());
-//     registry.add(markdown.clone());
-//     registry.add(Arc::new(rust_lang()));
-//     registry.add(Arc::new(ruby_lang()));
-
-//     let mut buffer = Buffer::new(
-//         0,
-//         0,
-//         r#"
-//             This is a code block:
-
-//             ```rs
-//             fn foo() {}
-//             ```
-//         "#
-//         .unindent(),
-//     );
-
-//     let mut syntax_map = SyntaxMap::new();
-//     syntax_map.set_language_registry(registry.clone());
-//     syntax_map.reparse(markdown.clone(), &buffer);
-//     assert_layers_for_range(
-//             &syntax_map,
-//             &buffer,
-//             Point::new(3, 0)..Point::new(3, 0),
-//             &[
-//                 "...(fenced_code_block (fenced_code_block_delimiter) (info_string (language)) (code_fence_content) (fenced_code_block_delimiter...",
-//                 "...(function_item name: (identifier) parameters: (parameters) body: (block)...",
-//             ],
-//         );
-
-//     // Replace Rust with Ruby in code block.
-//     let macro_name_range = range_for_text(&buffer, "rs");
-//     buffer.edit([(macro_name_range, "ruby")]);
-//     syntax_map.interpolate(&buffer);
-//     syntax_map.reparse(markdown.clone(), &buffer);
-//     assert_layers_for_range(
-//             &syntax_map,
-//             &buffer,
-//             Point::new(3, 0)..Point::new(3, 0),
-//             &[
-//                 "...(fenced_code_block (fenced_code_block_delimiter) (info_string (language)) (code_fence_content) (fenced_code_block_delimiter...",
-//                 "...(call method: (identifier) arguments: (argument_list (call method: (identifier) arguments: (argument_list) block: (block)...",
-//             ],
-//         );
-
-//     // Replace Ruby with a language that hasn't been loaded yet.
-//     let macro_name_range = range_for_text(&buffer, "ruby");
-//     buffer.edit([(macro_name_range, "html")]);
-//     syntax_map.interpolate(&buffer);
-//     syntax_map.reparse(markdown.clone(), &buffer);
-//     assert_layers_for_range(
-//             &syntax_map,
-//             &buffer,
-//             Point::new(3, 0)..Point::new(3, 0),
-//             &[
-//                 "...(fenced_code_block (fenced_code_block_delimiter) (info_string (language)) (code_fence_content) (fenced_code_block_delimiter..."
-//             ],
-//         );
-//     assert!(syntax_map.contains_unknown_injections());
-
-//     registry.add(Arc::new(html_lang()));
-//     syntax_map.reparse(markdown.clone(), &buffer);
-//     assert_layers_for_range(
-//             &syntax_map,
-//             &buffer,
-//             Point::new(3, 0)..Point::new(3, 0),
-//             &[
-//                 "...(fenced_code_block (fenced_code_block_delimiter) (info_string (language)) (code_fence_content) (fenced_code_block_delimiter...",
-//                 "(fragment (text))",
-//             ],
-//         );
-//     assert!(!syntax_map.contains_unknown_injections());
-// }
-
-// #[gpui::test]
-// fn test_typing_multiple_new_injections() {
-//     let (buffer, syntax_map) = test_edit_sequence(
-//         "Rust",
-//         &[
-//             "fn a() { dbg }",
-//             "fn a() { dbg«!» }",
-//             "fn a() { dbg!«()» }",
-//             "fn a() { dbg!(«b») }",
-//             "fn a() { dbg!(b«.») }",
-//             "fn a() { dbg!(b.«c») }",
-//             "fn a() { dbg!(b.c«()») }",
-//             "fn a() { dbg!(b.c(«vec»)) }",
-//             "fn a() { dbg!(b.c(vec«!»)) }",
-//             "fn a() { dbg!(b.c(vec!«[]»)) }",
-//             "fn a() { dbg!(b.c(vec![«d»])) }",
-//             "fn a() { dbg!(b.c(vec![d«.»])) }",
-//             "fn a() { dbg!(b.c(vec![d.«e»])) }",
-//         ],
-//     );
-
-//     assert_capture_ranges(
-//         &syntax_map,
-//         &buffer,
-//         &["field"],
-//         "fn a() { dbg!(b.«c»(vec![d.«e»])) }",
-//     );
-// }
-
-// #[gpui::test]
-// fn test_pasting_new_injection_line_between_others() {
-//     let (buffer, syntax_map) = test_edit_sequence(
-//         "Rust",
-//         &[
-//             "
-//                 fn a() {
-//                     b!(B {});
-//                     c!(C {});
-//                     d!(D {});
-//                     e!(E {});
-//                     f!(F {});
-//                     g!(G {});
-//                 }
-//             ",
-//             "
-//                 fn a() {
-//                     b!(B {});
-//                     c!(C {});
-//                     d!(D {});
-//                 «    h!(H {});
-//                 »    e!(E {});
-//                     f!(F {});
-//                     g!(G {});
-//                 }
-//             ",
-//         ],
-//     );
-
-//     assert_capture_ranges(
-//         &syntax_map,
-//         &buffer,
-//         &["struct"],
-//         "
-//         fn a() {
-//             b!(«B {}»);
-//             c!(«C {}»);
-//             d!(«D {}»);
-//             h!(«H {}»);
-//             e!(«E {}»);
-//             f!(«F {}»);
-//             g!(«G {}»);
-//         }
-//         ",
-//     );
-// }
-
-// #[gpui::test]
-// fn test_joining_injections_with_child_injections() {
-//     let (buffer, syntax_map) = test_edit_sequence(
-//         "Rust",
-//         &[
-//             "
-//                 fn a() {
-//                     b!(
-//                         c![one.two.three],
-//                         d![four.five.six],
-//                     );
-//                     e!(
-//                         f![seven.eight],
-//                     );
-//                 }
-//             ",
-//             "
-//                 fn a() {
-//                     b!(
-//                         c![one.two.three],
-//                         d![four.five.six],
-//                     ˇ    f![seven.eight],
-//                     );
-//                 }
-//             ",
-//         ],
-//     );
-
-//     assert_capture_ranges(
-//         &syntax_map,
-//         &buffer,
-//         &["field"],
-//         "
-//         fn a() {
-//             b!(
-//                 c![one.«two».«three»],
-//                 d![four.«five».«six»],
-//                 f![seven.«eight»],
-//             );
-//         }
-//         ",
-//     );
-// }
-
-// #[gpui::test]
-// fn test_editing_edges_of_injection() {
-//     test_edit_sequence(
-//         "Rust",
-//         &[
-//             "
-//                 fn a() {
-//                     b!(c!())
-//                 }
-//             ",
-//             "
-//                 fn a() {
-//                     «d»!(c!())
-//                 }
-//             ",
-//             "
-//                 fn a() {
-//                     «e»d!(c!())
-//                 }
-//             ",
-//             "
-//                 fn a() {
-//                     ed!«[»c!()«]»
-//                 }
-//             ",
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_edits_preceding_and_intersecting_injection() {
-//     test_edit_sequence(
-//         "Rust",
-//         &[
-//             //
-//             "const aaaaaaaaaaaa: B = c!(d(e.f));",
-//             "const aˇa: B = c!(d(eˇ));",
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_non_local_changes_create_injections() {
-//     test_edit_sequence(
-//         "Rust",
-//         &[
-//             "
-//                 // a! {
-//                     static B: C = d;
-//                 // }
-//             ",
-//             "
-//                 ˇa! {
-//                     static B: C = d;
-//                 ˇ}
-//             ",
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_creating_many_injections_in_one_edit() {
-//     test_edit_sequence(
-//         "Rust",
-//         &[
-//             "
-//                 fn a() {
-//                     one(Two::three(3));
-//                     four(Five::six(6));
-//                     seven(Eight::nine(9));
-//                 }
-//             ",
-//             "
-//                 fn a() {
-//                     one«!»(Two::three(3));
-//                     four«!»(Five::six(6));
-//                     seven«!»(Eight::nine(9));
-//                 }
-//             ",
-//             "
-//                 fn a() {
-//                     one!(Two::three«!»(3));
-//                     four!(Five::six«!»(6));
-//                     seven!(Eight::nine«!»(9));
-//                 }
-//             ",
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_editing_across_injection_boundary() {
-//     test_edit_sequence(
-//         "Rust",
-//         &[
-//             "
-//                 fn one() {
-//                     two();
-//                     three!(
-//                         three.four,
-//                         five.six,
-//                     );
-//                 }
-//             ",
-//             "
-//                 fn one() {
-//                     two();
-//                     th«irty_five![»
-//                         three.four,
-//                         five.six,
-//                     «   seven.eight,
-//                     ];»
-//                 }
-//             ",
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_removing_injection_by_replacing_across_boundary() {
-//     test_edit_sequence(
-//         "Rust",
-//         &[
-//             "
-//                 fn one() {
-//                     two!(
-//                         three.four,
-//                     );
-//                 }
-//             ",
-//             "
-//                 fn one() {
-//                     t«en
-//                         .eleven(
-//                         twelve,
-//                     »
-//                         three.four,
-//                     );
-//                 }
-//             ",
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_combined_injections_simple() {
-//     let (buffer, syntax_map) = test_edit_sequence(
-//         "ERB",
-//         &[
-//             "
-//                 <body>
-//                     <% if @one %>
-//                         <div class=one>
-//                     <% else %>
-//                         <div class=two>
-//                     <% end %>
-//                     </div>
-//                 </body>
-//             ",
-//             "
-//                 <body>
-//                     <% if @one %>
-//                         <div class=one>
-//                     ˇ else ˇ
-//                         <div class=two>
-//                     <% end %>
-//                     </div>
-//                 </body>
-//             ",
-//             "
-//                 <body>
-//                     <% if @one «;» end %>
-//                     </div>
-//                 </body>
-//             ",
-//         ],
-//     );
-
-//     assert_capture_ranges(
-//         &syntax_map,
-//         &buffer,
-//         &["tag", "ivar"],
-//         "
-//             <«body»>
-//                 <% if «@one» ; end %>
-//                 </«div»>
-//             </«body»>
-//         ",
-//     );
-// }
-
-// #[gpui::test]
-// fn test_combined_injections_empty_ranges() {
-//     test_edit_sequence(
-//         "ERB",
-//         &[
-//             "
-//                 <% if @one %>
-//                 <% else %>
-//                 <% end %>
-//             ",
-//             "
-//                 <% if @one %>
-//                 ˇ<% end %>
-//             ",
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_combined_injections_edit_edges_of_ranges() {
-//     let (buffer, syntax_map) = test_edit_sequence(
-//         "ERB",
-//         &[
-//             "
-//                 <%= one @two %>
-//                 <%= three @four %>
-//             ",
-//             "
-//                 <%= one @two %ˇ
-//                 <%= three @four %>
-//             ",
-//             "
-//                 <%= one @two %«>»
-//                 <%= three @four %>
-//             ",
-//         ],
-//     );
-
-//     assert_capture_ranges(
-//         &syntax_map,
-//         &buffer,
-//         &["tag", "ivar"],
-//         "
-//             <%= one «@two» %>
-//             <%= three «@four» %>
-//         ",
-//     );
-// }
-
-// #[gpui::test]
-// fn test_combined_injections_splitting_some_injections() {
-//     let (_buffer, _syntax_map) = test_edit_sequence(
-//         "ERB",
-//         &[
-//             r#"
-//                 <%A if b(:c) %>
-//                 d
-//                 <% end %>
-//                 eee
-//                 <% f %>
-//             "#,
-//             r#"
-//                 <%« AAAAAAA %>
-//                 hhhhhhh
-//                 <%=» if b(:c) %>
-//                 d
-//                 <% end %>
-//                 eee
-//                 <% f %>
-//             "#,
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_combined_injections_editing_after_last_injection() {
-//     test_edit_sequence(
-//         "ERB",
-//         &[
-//             r#"
-//                 <% foo %>
-//                 <div></div>
-//                 <% bar %>
-//             "#,
-//             r#"
-//                 <% foo %>
-//                 <div></div>
-//                 <% bar %>«
-//                 more text»
-//             "#,
-//         ],
-//     );
-// }
-
-// #[gpui::test]
-// fn test_combined_injections_inside_injections() {
-//     let (buffer, syntax_map) = test_edit_sequence(
-//         "Markdown",
-//         &[
-//             r#"
-//                 here is
-//                 some
-//                 ERB code:
-
-//                 ```erb
-//                 <ul>
-//                 <% people.each do |person| %>
-//                     <li><%= person.name %></li>
-//                     <li><%= person.age %></li>
-//                 <% end %>
-//                 </ul>
-//                 ```
-//             "#,
-//             r#"
-//                 here is
-//                 some
-//                 ERB code:
-
-//                 ```erb
-//                 <ul>
-//                 <% people«2».each do |person| %>
-//                     <li><%= person.name %></li>
-//                     <li><%= person.age %></li>
-//                 <% end %>
-//                 </ul>
-//                 ```
-//             "#,
-//             // Inserting a comment character inside one code directive
-//             // does not cause the other code directive to become a comment,
-//             // because newlines are included in between each injection range.
-//             r#"
-//                 here is
-//                 some
-//                 ERB code:
-
-//                 ```erb
-//                 <ul>
-//                 <% people2.each do |person| %>
-//                     <li><%= «# »person.name %></li>
-//                     <li><%= person.age %></li>
-//                 <% end %>
-//                 </ul>
-//                 ```
-//             "#,
-//         ],
-//     );
-
-//     // Check that the code directive below the ruby comment is
-//     // not parsed as a comment.
-//     assert_capture_ranges(
-//         &syntax_map,
-//         &buffer,
-//         &["method"],
-//         "
-//             here is
-//             some
-//             ERB code:
-
-//             ```erb
-//             <ul>
-//             <% people2.«each» do |person| %>
-//                 <li><%= # person.name %></li>
-//                 <li><%= person.«age» %></li>
-//             <% end %>
-//             </ul>
-//             ```
-//         ",
-//     );
-// }
-
-// #[gpui::test]
-// fn test_empty_combined_injections_inside_injections() {
-//     let (buffer, syntax_map) = test_edit_sequence(
-//         "Markdown",
-//         &[r#"
-//             ```erb
-//             hello
-//             ```
-
-//             goodbye
-//         "#],
-//     );
-
-//     assert_layers_for_range(
-//         &syntax_map,
-//         &buffer,
-//         Point::new(0, 0)..Point::new(5, 0),
-//         &[
-//             "...(paragraph)...",
-//             "(template...",
-//             "(fragment...",
-//             // The ruby syntax tree should be empty, since there are
-//             // no interpolations in the ERB template.
-//             "(program)",
-//         ],
-//     );
-// }
-
-// #[gpui::test(iterations = 50)]
-// fn test_random_syntax_map_edits_rust_macros(rng: StdRng) {
-//     let text = r#"
-//         fn test_something() {
-//             let vec = vec![5, 1, 3, 8];
-//             assert_eq!(
-//                 vec
-//                     .into_iter()
-//                     .map(|i| i * 2)
-//                     .collect::<Vec<usize>>(),
-//                 vec![
-//                     5 * 2, 1 * 2, 3 * 2, 8 * 2
-//                 ],
-//             );
-//         }
-//     "#
-//     .unindent()
-//     .repeat(2);
-
-//     let registry = Arc::new(LanguageRegistry::test());
-//     let language = Arc::new(rust_lang());
-//     registry.add(language.clone());
-
-//     test_random_edits(text, registry, language, rng);
-// }
-
-// #[gpui::test(iterations = 50)]
-// fn test_random_syntax_map_edits_with_erb(rng: StdRng) {
-//     let text = r#"
-//         <div id="main">
-//         <% if one?(:two) %>
-//             <p class="three" four>
-//             <%= yield :five %>
-//             </p>
-//         <% elsif Six.seven(8) %>
-//             <p id="three" four>
-//             <%= yield :five %>
-//             </p>
-//         <% else %>
-//             <span>Ok</span>
-//         <% end %>
-//         </div>
-//     "#
-//     .unindent()
-//     .repeat(5);
-
-//     let registry = Arc::new(LanguageRegistry::test());
-//     let language = Arc::new(erb_lang());
-//     registry.add(language.clone());
-//     registry.add(Arc::new(ruby_lang()));
-//     registry.add(Arc::new(html_lang()));
-
-//     test_random_edits(text, registry, language, rng);
-// }
-
-// #[gpui::test(iterations = 50)]
-// fn test_random_syntax_map_edits_with_heex(rng: StdRng) {
-//     let text = r#"
-//         defmodule TheModule do
-//             def the_method(assigns) do
-//                 ~H"""
-//                 <%= if @empty do %>
-//                     <div class="h-4"></div>
-//                 <% else %>
-//                     <div class="max-w-2xl w-full animate-pulse">
-//                     <div class="flex-1 space-y-4">
-//                         <div class={[@bg_class, "h-4 rounded-lg w-3/4"]}></div>
-//                         <div class={[@bg_class, "h-4 rounded-lg"]}></div>
-//                         <div class={[@bg_class, "h-4 rounded-lg w-5/6"]}></div>
-//                     </div>
-//                     </div>
-//                 <% end %>
-//                 """
-//             end
-//         end
-//     "#
-//     .unindent()
-//     .repeat(3);
-
-//     let registry = Arc::new(LanguageRegistry::test());
-//     let language = Arc::new(elixir_lang());
-//     registry.add(language.clone());
-//     registry.add(Arc::new(heex_lang()));
-//     registry.add(Arc::new(html_lang()));
-
-//     test_random_edits(text, registry, language, rng);
-// }
-
-// fn test_random_edits(
-//     text: String,
-//     registry: Arc<LanguageRegistry>,
-//     language: Arc<Language>,
-//     mut rng: StdRng,
-// ) {
-//     let operations = env::var("OPERATIONS")
-//         .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
-//         .unwrap_or(10);
-
-//     let mut buffer = Buffer::new(0, 0, text);
-
-//     let mut syntax_map = SyntaxMap::new();
-//     syntax_map.set_language_registry(registry.clone());
-//     syntax_map.reparse(language.clone(), &buffer);
-
-//     let mut reference_syntax_map = SyntaxMap::new();
-//     reference_syntax_map.set_language_registry(registry.clone());
-
-//     log::info!("initial text:\n{}", buffer.text());
-
-//     for _ in 0..operations {
-//         let prev_buffer = buffer.snapshot();
-//         let prev_syntax_map = syntax_map.snapshot();
-
-//         buffer.randomly_edit(&mut rng, 3);
-//         log::info!("text:\n{}", buffer.text());
-
-//         syntax_map.interpolate(&buffer);
-//         check_interpolation(&prev_syntax_map, &syntax_map, &prev_buffer, &buffer);
-
-//         syntax_map.reparse(language.clone(), &buffer);
-
-//         reference_syntax_map.clear();
-//         reference_syntax_map.reparse(language.clone(), &buffer);
-//     }
-
-//     for i in 0..operations {
-//         let i = operations - i - 1;
-//         buffer.undo();
-//         log::info!("undoing operation {}", i);
-//         log::info!("text:\n{}", buffer.text());
-
-//         syntax_map.interpolate(&buffer);
-//         syntax_map.reparse(language.clone(), &buffer);
-
-//         reference_syntax_map.clear();
-//         reference_syntax_map.reparse(language.clone(), &buffer);
-//         assert_eq!(
-//             syntax_map.layers(&buffer).len(),
-//             reference_syntax_map.layers(&buffer).len(),
-//             "wrong number of layers after undoing edit {i}"
-//         );
-//     }
-
-//     let layers = syntax_map.layers(&buffer);
-//     let reference_layers = reference_syntax_map.layers(&buffer);
-//     for (edited_layer, reference_layer) in layers.into_iter().zip(reference_layers.into_iter()) {
-//         assert_eq!(
-//             edited_layer.node().to_sexp(),
-//             reference_layer.node().to_sexp()
-//         );
-//         assert_eq!(edited_layer.node().range(), reference_layer.node().range());
-//     }
-// }
-
-// fn check_interpolation(
-//     old_syntax_map: &SyntaxSnapshot,
-//     new_syntax_map: &SyntaxSnapshot,
-//     old_buffer: &BufferSnapshot,
-//     new_buffer: &BufferSnapshot,
-// ) {
-//     let edits = new_buffer
-//         .edits_since::<usize>(&old_buffer.version())
-//         .collect::<Vec<_>>();
-
-//     for (old_layer, new_layer) in old_syntax_map
-//         .layers
-//         .iter()
-//         .zip(new_syntax_map.layers.iter())
-//     {
-//         assert_eq!(old_layer.range, new_layer.range);
-//         let Some(old_tree) = old_layer.content.tree() else {
-//             continue;
-//         };
-//         let Some(new_tree) = new_layer.content.tree() else {
-//             continue;
-//         };
-//         let old_start_byte = old_layer.range.start.to_offset(old_buffer);
-//         let new_start_byte = new_layer.range.start.to_offset(new_buffer);
-//         let old_start_point = old_layer.range.start.to_point(old_buffer).to_ts_point();
-//         let new_start_point = new_layer.range.start.to_point(new_buffer).to_ts_point();
-//         let old_node = old_tree.root_node_with_offset(old_start_byte, old_start_point);
-//         let new_node = new_tree.root_node_with_offset(new_start_byte, new_start_point);
-//         check_node_edits(
-//             old_layer.depth,
-//             &old_layer.range,
-//             old_node,
-//             new_node,
-//             old_buffer,
-//             new_buffer,
-//             &edits,
-//         );
-//     }
-
-//     fn check_node_edits(
-//         depth: usize,
-//         range: &Range<Anchor>,
-//         old_node: Node,
-//         new_node: Node,
-//         old_buffer: &BufferSnapshot,
-//         new_buffer: &BufferSnapshot,
-//         edits: &[text::Edit<usize>],
-//     ) {
-//         assert_eq!(old_node.kind(), new_node.kind());
-
-//         let old_range = old_node.byte_range();
-//         let new_range = new_node.byte_range();
-
-//         let is_edited = edits
-//             .iter()
-//             .any(|edit| edit.new.start < new_range.end && edit.new.end > new_range.start);
-//         if is_edited {
-//             assert!(
-//                 new_node.has_changes(),
-//                 concat!(
-//                     "failed to mark node as edited.\n",
-//                     "layer depth: {}, old layer range: {:?}, new layer range: {:?},\n",
-//                     "node kind: {}, old node range: {:?}, new node range: {:?}",
-//                 ),
-//                 depth,
-//                 range.to_offset(old_buffer),
-//                 range.to_offset(new_buffer),
-//                 new_node.kind(),
-//                 old_range,
-//                 new_range,
-//             );
-//         }
-
-//         if !new_node.has_changes() {
-//             assert_eq!(
-//                 old_buffer
-//                     .text_for_range(old_range.clone())
-//                     .collect::<String>(),
-//                 new_buffer
-//                     .text_for_range(new_range.clone())
-//                     .collect::<String>(),
-//                 concat!(
-//                     "mismatched text for node\n",
-//                     "layer depth: {}, old layer range: {:?}, new layer range: {:?},\n",
-//                     "node kind: {}, old node range:{:?}, new node range:{:?}",
-//                 ),
-//                 depth,
-//                 range.to_offset(old_buffer),
-//                 range.to_offset(new_buffer),
-//                 new_node.kind(),
-//                 old_range,
-//                 new_range,
-//             );
-//         }
-
-//         for i in 0..new_node.child_count() {
-//             check_node_edits(
-//                 depth,
-//                 range,
-//                 old_node.child(i).unwrap(),
-//                 new_node.child(i).unwrap(),
-//                 old_buffer,
-//                 new_buffer,
-//                 edits,
-//             )
-//         }
-//     }
-// }
-
-// fn test_edit_sequence(language_name: &str, steps: &[&str]) -> (Buffer, SyntaxMap) {
-//     let registry = Arc::new(LanguageRegistry::test());
-//     registry.add(Arc::new(elixir_lang()));
-//     registry.add(Arc::new(heex_lang()));
-//     registry.add(Arc::new(rust_lang()));
-//     registry.add(Arc::new(ruby_lang()));
-//     registry.add(Arc::new(html_lang()));
-//     registry.add(Arc::new(erb_lang()));
-//     registry.add(Arc::new(markdown_lang()));
-
-//     let language = registry
-//         .language_for_name(language_name)
-//         .now_or_never()
-//         .unwrap()
-//         .unwrap();
-//     let mut buffer = Buffer::new(0, 0, Default::default());
-
-//     let mut mutated_syntax_map = SyntaxMap::new();
-//     mutated_syntax_map.set_language_registry(registry.clone());
-//     mutated_syntax_map.reparse(language.clone(), &buffer);
-
-//     for (i, marked_string) in steps.into_iter().enumerate() {
-//         let marked_string = marked_string.unindent();
-//         log::info!("incremental parse {i}: {marked_string:?}");
-//         buffer.edit_via_marked_text(&marked_string);
-
-//         // Reparse the syntax map
-//         mutated_syntax_map.interpolate(&buffer);
-//         mutated_syntax_map.reparse(language.clone(), &buffer);
-
-//         // Create a second syntax map from scratch
-//         log::info!("fresh parse {i}: {marked_string:?}");
-//         let mut reference_syntax_map = SyntaxMap::new();
-//         reference_syntax_map.set_language_registry(registry.clone());
-//         reference_syntax_map.reparse(language.clone(), &buffer);
-
-//         // Compare the mutated syntax map to the new syntax map
-//         let mutated_layers = mutated_syntax_map.layers(&buffer);
-//         let reference_layers = reference_syntax_map.layers(&buffer);
-//         assert_eq!(
-//             mutated_layers.len(),
-//             reference_layers.len(),
-//             "wrong number of layers at step {i}"
-//         );
-//         for (edited_layer, reference_layer) in
-//             mutated_layers.into_iter().zip(reference_layers.into_iter())
-//         {
-//             assert_eq!(
-//                 edited_layer.node().to_sexp(),
-//                 reference_layer.node().to_sexp(),
-//                 "different layer at step {i}"
-//             );
-//             assert_eq!(
-//                 edited_layer.node().range(),
-//                 reference_layer.node().range(),
-//                 "different layer at step {i}"
-//             );
-//         }
-//     }
-
-//     (buffer, mutated_syntax_map)
-// }
-
-// fn html_lang() -> Language {
-//     Language::new(
-//         LanguageConfig {
-//             name: "HTML".into(),
-//             path_suffixes: vec!["html".to_string()],
-//             ..Default::default()
-//         },
-//         Some(tree_sitter_html::language()),
-//     )
-//     .with_highlights_query(
-//         r#"
-//             (tag_name) @tag
-//             (erroneous_end_tag_name) @tag
-//             (attribute_name) @property
-//         "#,
-//     )
-//     .unwrap()
-// }
-
-// fn ruby_lang() -> Language {
-//     Language::new(
-//         LanguageConfig {
-//             name: "Ruby".into(),
-//             path_suffixes: vec!["rb".to_string()],
-//             ..Default::default()
-//         },
-//         Some(tree_sitter_ruby::language()),
-//     )
-//     .with_highlights_query(
-//         r#"
-//             ["if" "do" "else" "end"] @keyword
-//             (instance_variable) @ivar
-//             (call method: (identifier) @method)
-//         "#,
-//     )
-//     .unwrap()
-// }
-
-// fn erb_lang() -> Language {
-//     Language::new(
-//         LanguageConfig {
-//             name: "ERB".into(),
-//             path_suffixes: vec!["erb".to_string()],
-//             ..Default::default()
-//         },
-//         Some(tree_sitter_embedded_template::language()),
-//     )
-//     .with_highlights_query(
-//         r#"
-//             ["<%" "%>"] @keyword
-//         "#,
-//     )
-//     .unwrap()
-//     .with_injection_query(
-//         r#"
-//             (
-//                 (code) @content
-//                 (#set! "language" "ruby")
-//                 (#set! "combined")
-//             )
-
-//             (
-//                 (content) @content
-//                 (#set! "language" "html")
-//                 (#set! "combined")
-//             )
-//         "#,
-//     )
-//     .unwrap()
-// }
-
-// fn rust_lang() -> Language {
-//     Language::new(
-//         LanguageConfig {
-//             name: "Rust".into(),
-//             path_suffixes: vec!["rs".to_string()],
-//             ..Default::default()
-//         },
-//         Some(tree_sitter_rust::language()),
-//     )
-//     .with_highlights_query(
-//         r#"
-//             (field_identifier) @field
-//             (struct_expression) @struct
-//         "#,
-//     )
-//     .unwrap()
-//     .with_injection_query(
-//         r#"
-//             (macro_invocation
-//                 (token_tree) @content
-//                 (#set! "language" "rust"))
-//         "#,
-//     )
-//     .unwrap()
-// }
-
-// fn markdown_lang() -> Language {
-//     Language::new(
-//         LanguageConfig {
-//             name: "Markdown".into(),
-//             path_suffixes: vec!["md".into()],
-//             ..Default::default()
-//         },
-//         Some(tree_sitter_markdown::language()),
-//     )
-//     .with_injection_query(
-//         r#"
-//             (fenced_code_block
-//                 (info_string
-//                     (language) @language)
-//                 (code_fence_content) @content)
-//         "#,
-//     )
-//     .unwrap()
-// }
-
-// fn elixir_lang() -> Language {
-//     Language::new(
-//         LanguageConfig {
-//             name: "Elixir".into(),
-//             path_suffixes: vec!["ex".into()],
-//             ..Default::default()
-//         },
-//         Some(tree_sitter_elixir::language()),
-//     )
-//     .with_highlights_query(
-//         r#"
-
-//         "#,
-//     )
-//     .unwrap()
-// }
-
-// fn heex_lang() -> Language {
-//     Language::new(
-//         LanguageConfig {
-//             name: "HEEx".into(),
-//             path_suffixes: vec!["heex".into()],
-//             ..Default::default()
-//         },
-//         Some(tree_sitter_heex::language()),
-//     )
-//     .with_injection_query(
-//         r#"
-//         (
-//           (directive
-//             [
-//               (partial_expression_value)
-//               (expression_value)
-//               (ending_expression_value)
-//             ] @content)
-//           (#set! language "elixir")
-//           (#set! combined)
-//         )
-
-//         ((expression (expression_value) @content)
-//          (#set! language "elixir"))
-//         "#,
-//     )
-//     .unwrap()
-// }
-
-// fn range_for_text(buffer: &Buffer, text: &str) -> Range<usize> {
-//     let start = buffer.as_rope().to_string().find(text).unwrap();
-//     start..start + text.len()
-// }
-
-// #[track_caller]
-// fn assert_layers_for_range(
-//     syntax_map: &SyntaxMap,
-//     buffer: &BufferSnapshot,
-//     range: Range<Point>,
-//     expected_layers: &[&str],
-// ) {
-//     let layers = syntax_map
-//         .layers_for_range(range, &buffer)
-//         .collect::<Vec<_>>();
-//     assert_eq!(
-//         layers.len(),
-//         expected_layers.len(),
-//         "wrong number of layers"
-//     );
-//     for (i, (layer, expected_s_exp)) in layers.iter().zip(expected_layers.iter()).enumerate() {
-//         let actual_s_exp = layer.node().to_sexp();
-//         assert!(
-//             string_contains_sequence(
-//                 &actual_s_exp,
-//                 &expected_s_exp.split("...").collect::<Vec<_>>()
-//             ),
-//             "layer {i}:\n\nexpected: {expected_s_exp}\nactual:   {actual_s_exp}",
-//         );
-//     }
-// }
-
-// fn assert_capture_ranges(
-//     syntax_map: &SyntaxMap,
-//     buffer: &BufferSnapshot,
-//     highlight_query_capture_names: &[&str],
-//     marked_string: &str,
-// ) {
-//     let mut actual_ranges = Vec::<Range<usize>>::new();
-//     let captures = syntax_map.captures(0..buffer.len(), buffer, |grammar| {
-//         grammar.highlights_query.as_ref()
-//     });
-//     let queries = captures
-//         .grammars()
-//         .iter()
-//         .map(|grammar| grammar.highlights_query.as_ref().unwrap())
-//         .collect::<Vec<_>>();
-//     for capture in captures {
-//         let name = &queries[capture.grammar_index].capture_names()[capture.index as usize];
-//         if highlight_query_capture_names.contains(&name.as_str()) {
-//             actual_ranges.push(capture.node.byte_range());
-//         }
-//     }
-
-//     let (text, expected_ranges) = marked_text_ranges(&marked_string.unindent(), false);
-//     assert_eq!(text, buffer.text());
-//     assert_eq!(actual_ranges, expected_ranges);
-// }
-
-// pub fn string_contains_sequence(text: &str, parts: &[&str]) -> bool {
-//     let mut last_part_end = 0;
-//     for part in parts {
-//         if let Some(start_ix) = text[last_part_end..].find(part) {
-//             last_part_end = start_ix + part.len();
-//         } else {
-//             return false;
-//         }
-//     }
-//     true
-// }
+use super::*;
+use crate::LanguageConfig;
+use rand::rngs::StdRng;
+use std::{env, ops::Range, sync::Arc};
+use text::Buffer;
+use tree_sitter::Node;
+use unindent::Unindent as _;
+use util::test::marked_text_ranges;
+
+#[test]
+fn test_splice_included_ranges() {
+    let ranges = vec![ts_range(20..30), ts_range(50..60), ts_range(80..90)];
+
+    let (new_ranges, change) = splice_included_ranges(
+        ranges.clone(),
+        &[54..56, 58..68],
+        &[ts_range(50..54), ts_range(59..67)],
+    );
+    assert_eq!(
+        new_ranges,
+        &[
+            ts_range(20..30),
+            ts_range(50..54),
+            ts_range(59..67),
+            ts_range(80..90),
+        ]
+    );
+    assert_eq!(change, 1..3);
+
+    let (new_ranges, change) = splice_included_ranges(ranges.clone(), &[70..71, 91..100], &[]);
+    assert_eq!(
+        new_ranges,
+        &[ts_range(20..30), ts_range(50..60), ts_range(80..90)]
+    );
+    assert_eq!(change, 2..3);
+
+    let (new_ranges, change) =
+        splice_included_ranges(ranges.clone(), &[], &[ts_range(0..2), ts_range(70..75)]);
+    assert_eq!(
+        new_ranges,
+        &[
+            ts_range(0..2),
+            ts_range(20..30),
+            ts_range(50..60),
+            ts_range(70..75),
+            ts_range(80..90)
+        ]
+    );
+    assert_eq!(change, 0..4);
+
+    let (new_ranges, change) =
+        splice_included_ranges(ranges.clone(), &[30..50], &[ts_range(25..55)]);
+    assert_eq!(new_ranges, &[ts_range(25..55), ts_range(80..90)]);
+    assert_eq!(change, 0..1);
+
+    // does not create overlapping ranges
+    let (new_ranges, change) =
+        splice_included_ranges(ranges.clone(), &[0..18], &[ts_range(20..32)]);
+    assert_eq!(
+        new_ranges,
+        &[ts_range(20..32), ts_range(50..60), ts_range(80..90)]
+    );
+    assert_eq!(change, 0..1);
+
+    fn ts_range(range: Range<usize>) -> tree_sitter::Range {
+        tree_sitter::Range {
+            start_byte: range.start,
+            start_point: tree_sitter::Point {
+                row: 0,
+                column: range.start,
+            },
+            end_byte: range.end,
+            end_point: tree_sitter::Point {
+                row: 0,
+                column: range.end,
+            },
+        }
+    }
+}
+
+#[gpui2::test]
+fn test_syntax_map_layers_for_range() {
+    let registry = Arc::new(LanguageRegistry::test());
+    let language = Arc::new(rust_lang());
+    registry.add(language.clone());
+
+    let mut buffer = Buffer::new(
+        0,
+        0,
+        r#"
+            fn a() {
+                assert_eq!(
+                    b(vec![C {}]),
+                    vec![d.e],
+                );
+                println!("{}", f(|_| true));
+            }
+        "#
+        .unindent(),
+    );
+
+    let mut syntax_map = SyntaxMap::new();
+    syntax_map.set_language_registry(registry.clone());
+    syntax_map.reparse(language.clone(), &buffer);
+
+    assert_layers_for_range(
+        &syntax_map,
+        &buffer,
+        Point::new(2, 0)..Point::new(2, 0),
+        &[
+            "...(function_item ... (block (expression_statement (macro_invocation...",
+            "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
+        ],
+    );
+    assert_layers_for_range(
+        &syntax_map,
+        &buffer,
+        Point::new(2, 14)..Point::new(2, 16),
+        &[
+            "...(function_item ...",
+            "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
+            "...(array_expression (struct_expression ...",
+        ],
+    );
+    assert_layers_for_range(
+        &syntax_map,
+        &buffer,
+        Point::new(3, 14)..Point::new(3, 16),
+        &[
+            "...(function_item ...",
+            "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
+            "...(array_expression (field_expression ...",
+        ],
+    );
+    assert_layers_for_range(
+        &syntax_map,
+        &buffer,
+        Point::new(5, 12)..Point::new(5, 16),
+        &[
+            "...(function_item ...",
+            "...(call_expression ... (arguments (closure_expression ...",
+        ],
+    );
+
+    // Replace a vec! macro invocation with a plain slice, removing a syntactic layer.
+    let macro_name_range = range_for_text(&buffer, "vec!");
+    buffer.edit([(macro_name_range, "&")]);
+    syntax_map.interpolate(&buffer);
+    syntax_map.reparse(language.clone(), &buffer);
+
+    assert_layers_for_range(
+            &syntax_map,
+            &buffer,
+            Point::new(2, 14)..Point::new(2, 16),
+            &[
+                "...(function_item ...",
+                "...(tuple_expression (call_expression ... arguments: (arguments (reference_expression value: (array_expression...",
+            ],
+        );
+
+    // Put the vec! macro back, adding back the syntactic layer.
+    buffer.undo();
+    syntax_map.interpolate(&buffer);
+    syntax_map.reparse(language.clone(), &buffer);
+
+    assert_layers_for_range(
+        &syntax_map,
+        &buffer,
+        Point::new(2, 14)..Point::new(2, 16),
+        &[
+            "...(function_item ...",
+            "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
+            "...(array_expression (struct_expression ...",
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_dynamic_language_injection() {
+    let registry = Arc::new(LanguageRegistry::test());
+    let markdown = Arc::new(markdown_lang());
+    registry.add(markdown.clone());
+    registry.add(Arc::new(rust_lang()));
+    registry.add(Arc::new(ruby_lang()));
+
+    let mut buffer = Buffer::new(
+        0,
+        0,
+        r#"
+            This is a code block:
+
+            ```rs
+            fn foo() {}
+            ```
+        "#
+        .unindent(),
+    );
+
+    let mut syntax_map = SyntaxMap::new();
+    syntax_map.set_language_registry(registry.clone());
+    syntax_map.reparse(markdown.clone(), &buffer);
+    assert_layers_for_range(
+            &syntax_map,
+            &buffer,
+            Point::new(3, 0)..Point::new(3, 0),
+            &[
+                "...(fenced_code_block (fenced_code_block_delimiter) (info_string (language)) (code_fence_content) (fenced_code_block_delimiter...",
+                "...(function_item name: (identifier) parameters: (parameters) body: (block)...",
+            ],
+        );
+
+    // Replace Rust with Ruby in code block.
+    let macro_name_range = range_for_text(&buffer, "rs");
+    buffer.edit([(macro_name_range, "ruby")]);
+    syntax_map.interpolate(&buffer);
+    syntax_map.reparse(markdown.clone(), &buffer);
+    assert_layers_for_range(
+            &syntax_map,
+            &buffer,
+            Point::new(3, 0)..Point::new(3, 0),
+            &[
+                "...(fenced_code_block (fenced_code_block_delimiter) (info_string (language)) (code_fence_content) (fenced_code_block_delimiter...",
+                "...(call method: (identifier) arguments: (argument_list (call method: (identifier) arguments: (argument_list) block: (block)...",
+            ],
+        );
+
+    // Replace Ruby with a language that hasn't been loaded yet.
+    let macro_name_range = range_for_text(&buffer, "ruby");
+    buffer.edit([(macro_name_range, "html")]);
+    syntax_map.interpolate(&buffer);
+    syntax_map.reparse(markdown.clone(), &buffer);
+    assert_layers_for_range(
+            &syntax_map,
+            &buffer,
+            Point::new(3, 0)..Point::new(3, 0),
+            &[
+                "...(fenced_code_block (fenced_code_block_delimiter) (info_string (language)) (code_fence_content) (fenced_code_block_delimiter..."
+            ],
+        );
+    assert!(syntax_map.contains_unknown_injections());
+
+    registry.add(Arc::new(html_lang()));
+    syntax_map.reparse(markdown.clone(), &buffer);
+    assert_layers_for_range(
+            &syntax_map,
+            &buffer,
+            Point::new(3, 0)..Point::new(3, 0),
+            &[
+                "...(fenced_code_block (fenced_code_block_delimiter) (info_string (language)) (code_fence_content) (fenced_code_block_delimiter...",
+                "(fragment (text))",
+            ],
+        );
+    assert!(!syntax_map.contains_unknown_injections());
+}
+
+#[gpui2::test]
+fn test_typing_multiple_new_injections() {
+    let (buffer, syntax_map) = test_edit_sequence(
+        "Rust",
+        &[
+            "fn a() { dbg }",
+            "fn a() { dbg«!» }",
+            "fn a() { dbg!«()» }",
+            "fn a() { dbg!(«b») }",
+            "fn a() { dbg!(b«.») }",
+            "fn a() { dbg!(b.«c») }",
+            "fn a() { dbg!(b.c«()») }",
+            "fn a() { dbg!(b.c(«vec»)) }",
+            "fn a() { dbg!(b.c(vec«!»)) }",
+            "fn a() { dbg!(b.c(vec!«[]»)) }",
+            "fn a() { dbg!(b.c(vec![«d»])) }",
+            "fn a() { dbg!(b.c(vec![d«.»])) }",
+            "fn a() { dbg!(b.c(vec![d.«e»])) }",
+        ],
+    );
+
+    assert_capture_ranges(
+        &syntax_map,
+        &buffer,
+        &["field"],
+        "fn a() { dbg!(b.«c»(vec![d.«e»])) }",
+    );
+}
+
+#[gpui2::test]
+fn test_pasting_new_injection_line_between_others() {
+    let (buffer, syntax_map) = test_edit_sequence(
+        "Rust",
+        &[
+            "
+                fn a() {
+                    b!(B {});
+                    c!(C {});
+                    d!(D {});
+                    e!(E {});
+                    f!(F {});
+                    g!(G {});
+                }
+            ",
+            "
+                fn a() {
+                    b!(B {});
+                    c!(C {});
+                    d!(D {});
+                «    h!(H {});
+                »    e!(E {});
+                    f!(F {});
+                    g!(G {});
+                }
+            ",
+        ],
+    );
+
+    assert_capture_ranges(
+        &syntax_map,
+        &buffer,
+        &["struct"],
+        "
+        fn a() {
+            b!(«B {}»);
+            c!(«C {}»);
+            d!(«D {}»);
+            h!(«H {}»);
+            e!(«E {}»);
+            f!(«F {}»);
+            g!(«G {}»);
+        }
+        ",
+    );
+}
+
+#[gpui2::test]
+fn test_joining_injections_with_child_injections() {
+    let (buffer, syntax_map) = test_edit_sequence(
+        "Rust",
+        &[
+            "
+                fn a() {
+                    b!(
+                        c![one.two.three],
+                        d![four.five.six],
+                    );
+                    e!(
+                        f![seven.eight],
+                    );
+                }
+            ",
+            "
+                fn a() {
+                    b!(
+                        c![one.two.three],
+                        d![four.five.six],
+                    ˇ    f![seven.eight],
+                    );
+                }
+            ",
+        ],
+    );
+
+    assert_capture_ranges(
+        &syntax_map,
+        &buffer,
+        &["field"],
+        "
+        fn a() {
+            b!(
+                c![one.«two».«three»],
+                d![four.«five».«six»],
+                f![seven.«eight»],
+            );
+        }
+        ",
+    );
+}
+
+#[gpui2::test]
+fn test_editing_edges_of_injection() {
+    test_edit_sequence(
+        "Rust",
+        &[
+            "
+                fn a() {
+                    b!(c!())
+                }
+            ",
+            "
+                fn a() {
+                    «d»!(c!())
+                }
+            ",
+            "
+                fn a() {
+                    «e»d!(c!())
+                }
+            ",
+            "
+                fn a() {
+                    ed!«[»c!()«]»
+                }
+            ",
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_edits_preceding_and_intersecting_injection() {
+    test_edit_sequence(
+        "Rust",
+        &[
+            //
+            "const aaaaaaaaaaaa: B = c!(d(e.f));",
+            "const aˇa: B = c!(d(eˇ));",
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_non_local_changes_create_injections() {
+    test_edit_sequence(
+        "Rust",
+        &[
+            "
+                // a! {
+                    static B: C = d;
+                // }
+            ",
+            "
+                ˇa! {
+                    static B: C = d;
+                ˇ}
+            ",
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_creating_many_injections_in_one_edit() {
+    test_edit_sequence(
+        "Rust",
+        &[
+            "
+                fn a() {
+                    one(Two::three(3));
+                    four(Five::six(6));
+                    seven(Eight::nine(9));
+                }
+            ",
+            "
+                fn a() {
+                    one«!»(Two::three(3));
+                    four«!»(Five::six(6));
+                    seven«!»(Eight::nine(9));
+                }
+            ",
+            "
+                fn a() {
+                    one!(Two::three«!»(3));
+                    four!(Five::six«!»(6));
+                    seven!(Eight::nine«!»(9));
+                }
+            ",
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_editing_across_injection_boundary() {
+    test_edit_sequence(
+        "Rust",
+        &[
+            "
+                fn one() {
+                    two();
+                    three!(
+                        three.four,
+                        five.six,
+                    );
+                }
+            ",
+            "
+                fn one() {
+                    two();
+                    th«irty_five![»
+                        three.four,
+                        five.six,
+                    «   seven.eight,
+                    ];»
+                }
+            ",
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_removing_injection_by_replacing_across_boundary() {
+    test_edit_sequence(
+        "Rust",
+        &[
+            "
+                fn one() {
+                    two!(
+                        three.four,
+                    );
+                }
+            ",
+            "
+                fn one() {
+                    t«en
+                        .eleven(
+                        twelve,
+                    »
+                        three.four,
+                    );
+                }
+            ",
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_combined_injections_simple() {
+    let (buffer, syntax_map) = test_edit_sequence(
+        "ERB",
+        &[
+            "
+                <body>
+                    <% if @one %>
+                        <div class=one>
+                    <% else %>
+                        <div class=two>
+                    <% end %>
+                    </div>
+                </body>
+            ",
+            "
+                <body>
+                    <% if @one %>
+                        <div class=one>
+                    ˇ else ˇ
+                        <div class=two>
+                    <% end %>
+                    </div>
+                </body>
+            ",
+            "
+                <body>
+                    <% if @one «;» end %>
+                    </div>
+                </body>
+            ",
+        ],
+    );
+
+    assert_capture_ranges(
+        &syntax_map,
+        &buffer,
+        &["tag", "ivar"],
+        "
+            <«body»>
+                <% if «@one» ; end %>
+                </«div»>
+            </«body»>
+        ",
+    );
+}
+
+#[gpui2::test]
+fn test_combined_injections_empty_ranges() {
+    test_edit_sequence(
+        "ERB",
+        &[
+            "
+                <% if @one %>
+                <% else %>
+                <% end %>
+            ",
+            "
+                <% if @one %>
+                ˇ<% end %>
+            ",
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_combined_injections_edit_edges_of_ranges() {
+    let (buffer, syntax_map) = test_edit_sequence(
+        "ERB",
+        &[
+            "
+                <%= one @two %>
+                <%= three @four %>
+            ",
+            "
+                <%= one @two %ˇ
+                <%= three @four %>
+            ",
+            "
+                <%= one @two %«>»
+                <%= three @four %>
+            ",
+        ],
+    );
+
+    assert_capture_ranges(
+        &syntax_map,
+        &buffer,
+        &["tag", "ivar"],
+        "
+            <%= one «@two» %>
+            <%= three «@four» %>
+        ",
+    );
+}
+
+#[gpui2::test]
+fn test_combined_injections_splitting_some_injections() {
+    let (_buffer, _syntax_map) = test_edit_sequence(
+        "ERB",
+        &[
+            r#"
+                <%A if b(:c) %>
+                d
+                <% end %>
+                eee
+                <% f %>
+            "#,
+            r#"
+                <%« AAAAAAA %>
+                hhhhhhh
+                <%=» if b(:c) %>
+                d
+                <% end %>
+                eee
+                <% f %>
+            "#,
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_combined_injections_editing_after_last_injection() {
+    test_edit_sequence(
+        "ERB",
+        &[
+            r#"
+                <% foo %>
+                <div></div>
+                <% bar %>
+            "#,
+            r#"
+                <% foo %>
+                <div></div>
+                <% bar %>«
+                more text»
+            "#,
+        ],
+    );
+}
+
+#[gpui2::test]
+fn test_combined_injections_inside_injections() {
+    let (buffer, syntax_map) = test_edit_sequence(
+        "Markdown",
+        &[
+            r#"
+                here is
+                some
+                ERB code:
+
+                ```erb
+                <ul>
+                <% people.each do |person| %>
+                    <li><%= person.name %></li>
+                    <li><%= person.age %></li>
+                <% end %>
+                </ul>
+                ```
+            "#,
+            r#"
+                here is
+                some
+                ERB code:
+
+                ```erb
+                <ul>
+                <% people«2».each do |person| %>
+                    <li><%= person.name %></li>
+                    <li><%= person.age %></li>
+                <% end %>
+                </ul>
+                ```
+            "#,
+            // Inserting a comment character inside one code directive
+            // does not cause the other code directive to become a comment,
+            // because newlines are included in between each injection range.
+            r#"
+                here is
+                some
+                ERB code:
+
+                ```erb
+                <ul>
+                <% people2.each do |person| %>
+                    <li><%= «# »person.name %></li>
+                    <li><%= person.age %></li>
+                <% end %>
+                </ul>
+                ```
+            "#,
+        ],
+    );
+
+    // Check that the code directive below the ruby comment is
+    // not parsed as a comment.
+    assert_capture_ranges(
+        &syntax_map,
+        &buffer,
+        &["method"],
+        "
+            here is
+            some
+            ERB code:
+
+            ```erb
+            <ul>
+            <% people2.«each» do |person| %>
+                <li><%= # person.name %></li>
+                <li><%= person.«age» %></li>
+            <% end %>
+            </ul>
+            ```
+        ",
+    );
+}
+
+#[gpui2::test]
+fn test_empty_combined_injections_inside_injections() {
+    let (buffer, syntax_map) = test_edit_sequence(
+        "Markdown",
+        &[r#"
+            ```erb
+            hello
+            ```
+
+            goodbye
+        "#],
+    );
+
+    assert_layers_for_range(
+        &syntax_map,
+        &buffer,
+        Point::new(0, 0)..Point::new(5, 0),
+        &[
+            "...(paragraph)...",
+            "(template...",
+            "(fragment...",
+            // The ruby syntax tree should be empty, since there are
+            // no interpolations in the ERB template.
+            "(program)",
+        ],
+    );
+}
+
+#[gpui2::test(iterations = 50)]
+fn test_random_syntax_map_edits_rust_macros(rng: StdRng) {
+    let text = r#"
+        fn test_something() {
+            let vec = vec![5, 1, 3, 8];
+            assert_eq!(
+                vec
+                    .into_iter()
+                    .map(|i| i * 2)
+                    .collect::<Vec<usize>>(),
+                vec![
+                    5 * 2, 1 * 2, 3 * 2, 8 * 2
+                ],
+            );
+        }
+    "#
+    .unindent()
+    .repeat(2);
+
+    let registry = Arc::new(LanguageRegistry::test());
+    let language = Arc::new(rust_lang());
+    registry.add(language.clone());
+
+    test_random_edits(text, registry, language, rng);
+}
+
+#[gpui2::test(iterations = 50)]
+fn test_random_syntax_map_edits_with_erb(rng: StdRng) {
+    let text = r#"
+        <div id="main">
+        <% if one?(:two) %>
+            <p class="three" four>
+            <%= yield :five %>
+            </p>
+        <% elsif Six.seven(8) %>
+            <p id="three" four>
+            <%= yield :five %>
+            </p>
+        <% else %>
+            <span>Ok</span>
+        <% end %>
+        </div>
+    "#
+    .unindent()
+    .repeat(5);
+
+    let registry = Arc::new(LanguageRegistry::test());
+    let language = Arc::new(erb_lang());
+    registry.add(language.clone());
+    registry.add(Arc::new(ruby_lang()));
+    registry.add(Arc::new(html_lang()));
+
+    test_random_edits(text, registry, language, rng);
+}
+
+#[gpui2::test(iterations = 50)]
+fn test_random_syntax_map_edits_with_heex(rng: StdRng) {
+    let text = r#"
+        defmodule TheModule do
+            def the_method(assigns) do
+                ~H"""
+                <%= if @empty do %>
+                    <div class="h-4"></div>
+                <% else %>
+                    <div class="max-w-2xl w-full animate-pulse">
+                    <div class="flex-1 space-y-4">
+                        <div class={[@bg_class, "h-4 rounded-lg w-3/4"]}></div>
+                        <div class={[@bg_class, "h-4 rounded-lg"]}></div>
+                        <div class={[@bg_class, "h-4 rounded-lg w-5/6"]}></div>
+                    </div>
+                    </div>
+                <% end %>
+                """
+            end
+        end
+    "#
+    .unindent()
+    .repeat(3);
+
+    let registry = Arc::new(LanguageRegistry::test());
+    let language = Arc::new(elixir_lang());
+    registry.add(language.clone());
+    registry.add(Arc::new(heex_lang()));
+    registry.add(Arc::new(html_lang()));
+
+    test_random_edits(text, registry, language, rng);
+}
+
+fn test_random_edits(
+    text: String,
+    registry: Arc<LanguageRegistry>,
+    language: Arc<Language>,
+    mut rng: StdRng,
+) {
+    let operations = env::var("OPERATIONS")
+        .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
+        .unwrap_or(10);
+
+    let mut buffer = Buffer::new(0, 0, text);
+
+    let mut syntax_map = SyntaxMap::new();
+    syntax_map.set_language_registry(registry.clone());
+    syntax_map.reparse(language.clone(), &buffer);
+
+    let mut reference_syntax_map = SyntaxMap::new();
+    reference_syntax_map.set_language_registry(registry.clone());
+
+    log::info!("initial text:\n{}", buffer.text());
+
+    for _ in 0..operations {
+        let prev_buffer = buffer.snapshot();
+        let prev_syntax_map = syntax_map.snapshot();
+
+        buffer.randomly_edit(&mut rng, 3);
+        log::info!("text:\n{}", buffer.text());
+
+        syntax_map.interpolate(&buffer);
+        check_interpolation(&prev_syntax_map, &syntax_map, &prev_buffer, &buffer);
+
+        syntax_map.reparse(language.clone(), &buffer);
+
+        reference_syntax_map.clear();
+        reference_syntax_map.reparse(language.clone(), &buffer);
+    }
+
+    for i in 0..operations {
+        let i = operations - i - 1;
+        buffer.undo();
+        log::info!("undoing operation {}", i);
+        log::info!("text:\n{}", buffer.text());
+
+        syntax_map.interpolate(&buffer);
+        syntax_map.reparse(language.clone(), &buffer);
+
+        reference_syntax_map.clear();
+        reference_syntax_map.reparse(language.clone(), &buffer);
+        assert_eq!(
+            syntax_map.layers(&buffer).len(),
+            reference_syntax_map.layers(&buffer).len(),
+            "wrong number of layers after undoing edit {i}"
+        );
+    }
+
+    let layers = syntax_map.layers(&buffer);
+    let reference_layers = reference_syntax_map.layers(&buffer);
+    for (edited_layer, reference_layer) in layers.into_iter().zip(reference_layers.into_iter()) {
+        assert_eq!(
+            edited_layer.node().to_sexp(),
+            reference_layer.node().to_sexp()
+        );
+        assert_eq!(edited_layer.node().range(), reference_layer.node().range());
+    }
+}
+
+fn check_interpolation(
+    old_syntax_map: &SyntaxSnapshot,
+    new_syntax_map: &SyntaxSnapshot,
+    old_buffer: &BufferSnapshot,
+    new_buffer: &BufferSnapshot,
+) {
+    let edits = new_buffer
+        .edits_since::<usize>(&old_buffer.version())
+        .collect::<Vec<_>>();
+
+    for (old_layer, new_layer) in old_syntax_map
+        .layers
+        .iter()
+        .zip(new_syntax_map.layers.iter())
+    {
+        assert_eq!(old_layer.range, new_layer.range);
+        let Some(old_tree) = old_layer.content.tree() else {
+            continue;
+        };
+        let Some(new_tree) = new_layer.content.tree() else {
+            continue;
+        };
+        let old_start_byte = old_layer.range.start.to_offset(old_buffer);
+        let new_start_byte = new_layer.range.start.to_offset(new_buffer);
+        let old_start_point = old_layer.range.start.to_point(old_buffer).to_ts_point();
+        let new_start_point = new_layer.range.start.to_point(new_buffer).to_ts_point();
+        let old_node = old_tree.root_node_with_offset(old_start_byte, old_start_point);
+        let new_node = new_tree.root_node_with_offset(new_start_byte, new_start_point);
+        check_node_edits(
+            old_layer.depth,
+            &old_layer.range,
+            old_node,
+            new_node,
+            old_buffer,
+            new_buffer,
+            &edits,
+        );
+    }
+
+    fn check_node_edits(
+        depth: usize,
+        range: &Range<Anchor>,
+        old_node: Node,
+        new_node: Node,
+        old_buffer: &BufferSnapshot,
+        new_buffer: &BufferSnapshot,
+        edits: &[text::Edit<usize>],
+    ) {
+        assert_eq!(old_node.kind(), new_node.kind());
+
+        let old_range = old_node.byte_range();
+        let new_range = new_node.byte_range();
+
+        let is_edited = edits
+            .iter()
+            .any(|edit| edit.new.start < new_range.end && edit.new.end > new_range.start);
+        if is_edited {
+            assert!(
+                new_node.has_changes(),
+                concat!(
+                    "failed to mark node as edited.\n",
+                    "layer depth: {}, old layer range: {:?}, new layer range: {:?},\n",
+                    "node kind: {}, old node range: {:?}, new node range: {:?}",
+                ),
+                depth,
+                range.to_offset(old_buffer),
+                range.to_offset(new_buffer),
+                new_node.kind(),
+                old_range,
+                new_range,
+            );
+        }
+
+        if !new_node.has_changes() {
+            assert_eq!(
+                old_buffer
+                    .text_for_range(old_range.clone())
+                    .collect::<String>(),
+                new_buffer
+                    .text_for_range(new_range.clone())
+                    .collect::<String>(),
+                concat!(
+                    "mismatched text for node\n",
+                    "layer depth: {}, old layer range: {:?}, new layer range: {:?},\n",
+                    "node kind: {}, old node range:{:?}, new node range:{:?}",
+                ),
+                depth,
+                range.to_offset(old_buffer),
+                range.to_offset(new_buffer),
+                new_node.kind(),
+                old_range,
+                new_range,
+            );
+        }
+
+        for i in 0..new_node.child_count() {
+            check_node_edits(
+                depth,
+                range,
+                old_node.child(i).unwrap(),
+                new_node.child(i).unwrap(),
+                old_buffer,
+                new_buffer,
+                edits,
+            )
+        }
+    }
+}
+
+fn test_edit_sequence(language_name: &str, steps: &[&str]) -> (Buffer, SyntaxMap) {
+    let registry = Arc::new(LanguageRegistry::test());
+    registry.add(Arc::new(elixir_lang()));
+    registry.add(Arc::new(heex_lang()));
+    registry.add(Arc::new(rust_lang()));
+    registry.add(Arc::new(ruby_lang()));
+    registry.add(Arc::new(html_lang()));
+    registry.add(Arc::new(erb_lang()));
+    registry.add(Arc::new(markdown_lang()));
+
+    let language = registry
+        .language_for_name(language_name)
+        .now_or_never()
+        .unwrap()
+        .unwrap();
+    let mut buffer = Buffer::new(0, 0, Default::default());
+
+    let mut mutated_syntax_map = SyntaxMap::new();
+    mutated_syntax_map.set_language_registry(registry.clone());
+    mutated_syntax_map.reparse(language.clone(), &buffer);
+
+    for (i, marked_string) in steps.into_iter().enumerate() {
+        let marked_string = marked_string.unindent();
+        log::info!("incremental parse {i}: {marked_string:?}");
+        buffer.edit_via_marked_text(&marked_string);
+
+        // Reparse the syntax map
+        mutated_syntax_map.interpolate(&buffer);
+        mutated_syntax_map.reparse(language.clone(), &buffer);
+
+        // Create a second syntax map from scratch
+        log::info!("fresh parse {i}: {marked_string:?}");
+        let mut reference_syntax_map = SyntaxMap::new();
+        reference_syntax_map.set_language_registry(registry.clone());
+        reference_syntax_map.reparse(language.clone(), &buffer);
+
+        // Compare the mutated syntax map to the new syntax map
+        let mutated_layers = mutated_syntax_map.layers(&buffer);
+        let reference_layers = reference_syntax_map.layers(&buffer);
+        assert_eq!(
+            mutated_layers.len(),
+            reference_layers.len(),
+            "wrong number of layers at step {i}"
+        );
+        for (edited_layer, reference_layer) in
+            mutated_layers.into_iter().zip(reference_layers.into_iter())
+        {
+            assert_eq!(
+                edited_layer.node().to_sexp(),
+                reference_layer.node().to_sexp(),
+                "different layer at step {i}"
+            );
+            assert_eq!(
+                edited_layer.node().range(),
+                reference_layer.node().range(),
+                "different layer at step {i}"
+            );
+        }
+    }
+
+    (buffer, mutated_syntax_map)
+}
+
+fn html_lang() -> Language {
+    Language::new(
+        LanguageConfig {
+            name: "HTML".into(),
+            path_suffixes: vec!["html".to_string()],
+            ..Default::default()
+        },
+        Some(tree_sitter_html::language()),
+    )
+    .with_highlights_query(
+        r#"
+            (tag_name) @tag
+            (erroneous_end_tag_name) @tag
+            (attribute_name) @property
+        "#,
+    )
+    .unwrap()
+}
+
+fn ruby_lang() -> Language {
+    Language::new(
+        LanguageConfig {
+            name: "Ruby".into(),
+            path_suffixes: vec!["rb".to_string()],
+            ..Default::default()
+        },
+        Some(tree_sitter_ruby::language()),
+    )
+    .with_highlights_query(
+        r#"
+            ["if" "do" "else" "end"] @keyword
+            (instance_variable) @ivar
+            (call method: (identifier) @method)
+        "#,
+    )
+    .unwrap()
+}
+
+fn erb_lang() -> Language {
+    Language::new(
+        LanguageConfig {
+            name: "ERB".into(),
+            path_suffixes: vec!["erb".to_string()],
+            ..Default::default()
+        },
+        Some(tree_sitter_embedded_template::language()),
+    )
+    .with_highlights_query(
+        r#"
+            ["<%" "%>"] @keyword
+        "#,
+    )
+    .unwrap()
+    .with_injection_query(
+        r#"
+            (
+                (code) @content
+                (#set! "language" "ruby")
+                (#set! "combined")
+            )
+
+            (
+                (content) @content
+                (#set! "language" "html")
+                (#set! "combined")
+            )
+        "#,
+    )
+    .unwrap()
+}
+
+fn rust_lang() -> Language {
+    Language::new(
+        LanguageConfig {
+            name: "Rust".into(),
+            path_suffixes: vec!["rs".to_string()],
+            ..Default::default()
+        },
+        Some(tree_sitter_rust::language()),
+    )
+    .with_highlights_query(
+        r#"
+            (field_identifier) @field
+            (struct_expression) @struct
+        "#,
+    )
+    .unwrap()
+    .with_injection_query(
+        r#"
+            (macro_invocation
+                (token_tree) @content
+                (#set! "language" "rust"))
+        "#,
+    )
+    .unwrap()
+}
+
+fn markdown_lang() -> Language {
+    Language::new(
+        LanguageConfig {
+            name: "Markdown".into(),
+            path_suffixes: vec!["md".into()],
+            ..Default::default()
+        },
+        Some(tree_sitter_markdown::language()),
+    )
+    .with_injection_query(
+        r#"
+            (fenced_code_block
+                (info_string
+                    (language) @language)
+                (code_fence_content) @content)
+        "#,
+    )
+    .unwrap()
+}
+
+fn elixir_lang() -> Language {
+    Language::new(
+        LanguageConfig {
+            name: "Elixir".into(),
+            path_suffixes: vec!["ex".into()],
+            ..Default::default()
+        },
+        Some(tree_sitter_elixir::language()),
+    )
+    .with_highlights_query(
+        r#"
+
+        "#,
+    )
+    .unwrap()
+}
+
+fn heex_lang() -> Language {
+    Language::new(
+        LanguageConfig {
+            name: "HEEx".into(),
+            path_suffixes: vec!["heex".into()],
+            ..Default::default()
+        },
+        Some(tree_sitter_heex::language()),
+    )
+    .with_injection_query(
+        r#"
+        (
+          (directive
+            [
+              (partial_expression_value)
+              (expression_value)
+              (ending_expression_value)
+            ] @content)
+          (#set! language "elixir")
+          (#set! combined)
+        )
+
+        ((expression (expression_value) @content)
+         (#set! language "elixir"))
+        "#,
+    )
+    .unwrap()
+}
+
+fn range_for_text(buffer: &Buffer, text: &str) -> Range<usize> {
+    let start = buffer.as_rope().to_string().find(text).unwrap();
+    start..start + text.len()
+}
+
+#[track_caller]
+fn assert_layers_for_range(
+    syntax_map: &SyntaxMap,
+    buffer: &BufferSnapshot,
+    range: Range<Point>,
+    expected_layers: &[&str],
+) {
+    let layers = syntax_map
+        .layers_for_range(range, &buffer)
+        .collect::<Vec<_>>();
+    assert_eq!(
+        layers.len(),
+        expected_layers.len(),
+        "wrong number of layers"
+    );
+    for (i, (layer, expected_s_exp)) in layers.iter().zip(expected_layers.iter()).enumerate() {
+        let actual_s_exp = layer.node().to_sexp();
+        assert!(
+            string_contains_sequence(
+                &actual_s_exp,
+                &expected_s_exp.split("...").collect::<Vec<_>>()
+            ),
+            "layer {i}:\n\nexpected: {expected_s_exp}\nactual:   {actual_s_exp}",
+        );
+    }
+}
+
+fn assert_capture_ranges(
+    syntax_map: &SyntaxMap,
+    buffer: &BufferSnapshot,
+    highlight_query_capture_names: &[&str],
+    marked_string: &str,
+) {
+    let mut actual_ranges = Vec::<Range<usize>>::new();
+    let captures = syntax_map.captures(0..buffer.len(), buffer, |grammar| {
+        grammar.highlights_query.as_ref()
+    });
+    let queries = captures
+        .grammars()
+        .iter()
+        .map(|grammar| grammar.highlights_query.as_ref().unwrap())
+        .collect::<Vec<_>>();
+    for capture in captures {
+        let name = &queries[capture.grammar_index].capture_names()[capture.index as usize];
+        if highlight_query_capture_names.contains(&name.as_str()) {
+            actual_ranges.push(capture.node.byte_range());
+        }
+    }
+
+    let (text, expected_ranges) = marked_text_ranges(&marked_string.unindent(), false);
+    assert_eq!(text, buffer.text());
+    assert_eq!(actual_ranges, expected_ranges);
+}
+
+pub fn string_contains_sequence(text: &str, parts: &[&str]) -> bool {
+    let mut last_part_end = 0;
+    for part in parts {
+        if let Some(start_ix) = text[last_part_end..].find(part) {
+            last_part_end = start_ix + part.len();
+        } else {
+            return false;
+        }
+    }
+    true
+}