Extract HTML support into an extension (#10130)

This PR extracts HTML support into an extension and removes the built-in
HTML support from Zed.

Release Notes:

- Removed built-in support for HTML, in favor of making it available as
an extension. The HTML extension will be suggested for download when you
open a `.html`, `.htm`, or `.shtml` file.

extensions/html/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "zed_html"
+version = "0.0.1"
+edition = "2021"
+publish = false
+license = "Apache-2.0"
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/html.rs"
+crate-type = ["cdylib"]
+
+[dependencies]
+zed_extension_api = "0.0.4"

extensions/html/LICENSE-APACHE

@@ -0,0 +1 @@
+../../LICENSE-APACHE

extensions/html/extension.toml

@@ -0,0 +1,15 @@
+id = "html"
+name = "HTML"
+description = "HTML support."
+version = "0.0.1"
+schema_version = 1
+authors = ["Isaac Clayton <slightknack@gmail.com>"]
+repository = "https://github.com/zed-industries/zed"
+
+[language_servers.vscode-html-language-server]
+name = "vscode-html-language-server"
+language = "HTML"
+
+[grammars.html]
+repository = "https://github.com/tree-sitter/tree-sitter-html"
+commit = "bfa075d83c6b97cd48440b3829ab8d24a2319809"

extensions/html/languages/html/brackets.scm

@@ -0,0 +1,2 @@
+("<" @open ">" @close)
+("\"" @open "\"" @close)

extensions/html/languages/html/config.toml

@@ -0,0 +1,15 @@
+name = "HTML"
+grammar = "html"
+path_suffixes = ["html", "htm", "shtml"]
+autoclose_before = ">})"
+block_comment = ["<!-- ", " -->"]
+brackets = [
+    { start = "{", end = "}", close = true, newline = true },
+    { start = "[", end = "]", close = true, newline = true },
+    { start = "(", end = ")", close = true, newline = true },
+    { start = "\"", end = "\"", close = true, newline = false, not_in = ["comment", "string"] },
+    { start = "<", end = ">", close = true, newline = true, not_in = ["comment", "string"] },
+    { start = "!--", end = " --", close = true, newline = false, not_in = ["comment", "string"] },
+]
+word_characters = ["-"]
+prettier_parser_name = "html"

extensions/html/languages/html/highlights.scm

@@ -0,0 +1,16 @@
+(tag_name) @keyword
+(erroneous_end_tag_name) @keyword
+(doctype) @constant
+(attribute_name) @property
+(attribute_value) @string
+(comment) @comment
+
+"=" @operator
+
+[
+  "<"
+  ">"
+  "<!"
+  "</"
+  "/>"
+] @punctuation.bracket

extensions/html/languages/html/indents.scm

@@ -0,0 +1,6 @@
+(start_tag ">" @end) @indent
+(self_closing_tag "/>" @end) @indent
+
+(element
+  (start_tag) @start
+  (end_tag)? @end) @indent

extensions/html/languages/html/injections.scm

@@ -0,0 +1,7 @@
+(script_element
+  (raw_text) @content
+  (#set! "language" "javascript"))
+
+(style_element
+  (raw_text) @content
+  (#set! "language" "css"))

extensions/html/languages/html/overrides.scm

@@ -0,0 +1,2 @@
+(comment) @comment
+(quoted_attribute_value) @string

extensions/html/src/html.rs

@@ -0,0 +1,86 @@
+use std::{env, fs};
+use zed_extension_api::{self as zed, Result};
+
+const SERVER_PATH: &str =
+    "node_modules/vscode-langservers-extracted/bin/vscode-html-language-server";
+const PACKAGE_NAME: &str = "vscode-langservers-extracted";
+
+struct HtmlExtension {
+    did_find_server: bool,
+}
+
+impl HtmlExtension {
+    fn server_exists(&self) -> bool {
+        fs::metadata(SERVER_PATH).map_or(false, |stat| stat.is_file())
+    }
+
+    fn server_script_path(&mut self, config: zed::LanguageServerConfig) -> Result<String> {
+        let server_exists = self.server_exists();
+        if self.did_find_server && server_exists {
+            return Ok(SERVER_PATH.to_string());
+        }
+
+        zed::set_language_server_installation_status(
+            &config.name,
+            &zed::LanguageServerInstallationStatus::CheckingForUpdate,
+        );
+        let version = zed::npm_package_latest_version(PACKAGE_NAME)?;
+
+        if !server_exists
+            || zed::npm_package_installed_version(PACKAGE_NAME)?.as_ref() != Some(&version)
+        {
+            zed::set_language_server_installation_status(
+                &config.name,
+                &zed::LanguageServerInstallationStatus::Downloading,
+            );
+            let result = zed::npm_install_package(PACKAGE_NAME, &version);
+            match result {
+                Ok(()) => {
+                    if !self.server_exists() {
+                        Err(format!(
+                            "installed package '{PACKAGE_NAME}' did not contain expected path '{SERVER_PATH}'",
+                        ))?;
+                    }
+                }
+                Err(error) => {
+                    if !self.server_exists() {
+                        Err(error)?;
+                    }
+                }
+            }
+        }
+
+        self.did_find_server = true;
+        Ok(SERVER_PATH.to_string())
+    }
+}
+
+impl zed::Extension for HtmlExtension {
+    fn new() -> Self {
+        Self {
+            did_find_server: false,
+        }
+    }
+
+    fn language_server_command(
+        &mut self,
+        config: zed::LanguageServerConfig,
+        _worktree: &zed::Worktree,
+    ) -> Result<zed::Command> {
+        let server_path = self.server_script_path(config)?;
+        Ok(zed::Command {
+            command: zed::node_binary_path()?,
+            args: vec![
+                env::current_dir()
+                    .unwrap()
+                    .join(&server_path)
+                    .to_string_lossy()
+                    .to_string(),
+                "--stdio".to_string(),
+            ],
+            env: Default::default(),
+        })
+    }
+}
+
+zed::register_extension!(HtmlExtension);