Extract Terraform extension (#10479)

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

Release Notes:

- Removed built-in support for Terraform, in favor of making it
available as
an extension. The Terraform extension will be suggested for download
when you
open a `.tf`, `.tfvars`, or `.hcl` file.

extensions/terraform/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "zed_terraform"
+version = "0.0.1"
+edition = "2021"
+publish = false
+license = "Apache-2.0"
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/terraform.rs"
+crate-type = ["cdylib"]
+
+[dependencies]
+zed_extension_api = "0.0.6"

extensions/terraform/LICENSE-APACHE

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

extensions/terraform/extension.toml

@@ -0,0 +1,16 @@
+id = "terraform"
+name = "Terraform"
+description = "Terraform support."
+version = "0.0.1"
+schema_version = 1
+authors = ["Caius Durling <dev@caius.name>", "Daniel Banck <dbanck@users.noreply.github.com>"]
+repository = "https://github.com/zed-industries/zed"
+
+[language_servers.terraform-ls]
+name = "Terraform Language Server"
+languages = ["Terraform", "Terraform Vars"]
+language_ids = { Terraform = "terraform", "Terraform Vars" = "terraform-vars" }
+
+[grammars.hcl]
+repository = "https://github.com/MichaHoffmann/tree-sitter-hcl"
+commit = "e936d3fef8bac884661472dce71ad82284761eb1"

extensions/terraform/languages/hcl/config.toml

@@ -0,0 +1,14 @@
+name = "HCL"
+grammar = "hcl"
+path_suffixes = ["hcl"]
+line_comments = ["# ", "// "]
+block_comment = ["/*", "*/"]
+autoclose_before = ",}])"
+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 = false, not_in = ["comment", "string"] },
+    { start = "/*", end = " */", close = true, newline = false, not_in = ["comment", "string"] },
+]

extensions/terraform/languages/hcl/highlights.scm

@@ -0,0 +1,117 @@
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/cb79d2446196d25607eb1d982c96939abdf67b8e/queries/hcl/highlights.scm
+; highlights.scm
+[
+  "!"
+  "\*"
+  "/"
+  "%"
+  "\+"
+  "-"
+  ">"
+  ">="
+  "<"
+  "<="
+  "=="
+  "!="
+  "&&"
+  "||"
+] @operator
+
+[
+  "{"
+  "}"
+  "["
+  "]"
+  "("
+  ")"
+] @punctuation.bracket
+
+[
+  "."
+  ".*"
+  ","
+  "[*]"
+] @punctuation.delimiter
+
+[
+  (ellipsis)
+  "\?"
+  "=>"
+] @punctuation.special
+
+[
+  ":"
+  "="
+] @punctuation
+
+[
+  "for"
+  "endfor"
+  "in"
+  "if"
+  "else"
+  "endif"
+] @keyword
+
+[
+  (quoted_template_start) ; "
+  (quoted_template_end) ; "
+  (template_literal) ; non-interpolation/directive content
+] @string
+
+[
+  (heredoc_identifier) ; END
+  (heredoc_start) ; << or <<-
+] @punctuation.delimiter
+
+[
+  (template_interpolation_start) ; ${
+  (template_interpolation_end) ; }
+  (template_directive_start) ; %{
+  (template_directive_end) ; }
+  (strip_marker) ; ~
+] @punctuation.special
+
+(numeric_lit) @number
+
+(bool_lit) @boolean
+
+(null_lit) @constant
+
+(comment) @comment
+
+(identifier) @variable
+
+(body
+  (block
+    (identifier) @keyword))
+
+(body
+  (block
+    (body
+      (block
+        (identifier) @type))))
+
+(function_call
+  (identifier) @function)
+
+(attribute
+  (identifier) @variable)
+
+; { key: val }
+;
+; highlight identifier keys as though they were block attributes
+(object_elem
+  key:
+    (expression
+      (variable_expr
+        (identifier) @variable)))
+
+; var.foo, data.bar
+;
+; first element in get_attr is a variable.builtin or a reference to a variable.builtin
+(expression
+  (variable_expr
+    (identifier) @variable)
+  (get_attr
+    (identifier) @variable))

extensions/terraform/languages/hcl/indents.scm

@@ -0,0 +1,11 @@
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/hcl/indents.scm
+[
+  (block)
+  (object)
+  (tuple)
+  (function_call)
+] @indent
+
+(_ "[" "]" @end) @indent
+(_ "(" ")" @end) @indent
+(_ "{" "}" @end) @indent

extensions/terraform/languages/hcl/injections.scm

@@ -0,0 +1,6 @@
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/hcl/injections.scm
+
+(heredoc_template
+  (template_literal) @content
+  (heredoc_identifier) @language
+  (#downcase! @language))

extensions/terraform/languages/terraform-vars/config.toml

@@ -0,0 +1,14 @@
+name = "Terraform Vars"
+grammar = "hcl"
+path_suffixes = ["tfvars"]
+line_comments = ["# ", "// "]
+block_comment = ["/*", "*/"]
+autoclose_before = ",}])"
+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 = false, not_in = ["comment", "string"] },
+    { start = "/*", end = " */", close = true, newline = false, not_in = ["comment", "string"] },
+]

extensions/terraform/languages/terraform-vars/highlights.scm

@@ -0,0 +1,159 @@
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/cb79d2446196d25607eb1d982c96939abdf67b8e/queries/hcl/highlights.scm
+; highlights.scm
+[
+  "!"
+  "\*"
+  "/"
+  "%"
+  "\+"
+  "-"
+  ">"
+  ">="
+  "<"
+  "<="
+  "=="
+  "!="
+  "&&"
+  "||"
+] @operator
+
+[
+  "{"
+  "}"
+  "["
+  "]"
+  "("
+  ")"
+] @punctuation.bracket
+
+[
+  "."
+  ".*"
+  ","
+  "[*]"
+] @punctuation.delimiter
+
+[
+  (ellipsis)
+  "\?"
+  "=>"
+] @punctuation.special
+
+[
+  ":"
+  "="
+] @punctuation
+
+[
+  "for"
+  "endfor"
+  "in"
+  "if"
+  "else"
+  "endif"
+] @keyword
+
+[
+  (quoted_template_start) ; "
+  (quoted_template_end) ; "
+  (template_literal) ; non-interpolation/directive content
+] @string
+
+[
+  (heredoc_identifier) ; END
+  (heredoc_start) ; << or <<-
+] @punctuation.delimiter
+
+[
+  (template_interpolation_start) ; ${
+  (template_interpolation_end) ; }
+  (template_directive_start) ; %{
+  (template_directive_end) ; }
+  (strip_marker) ; ~
+] @punctuation.special
+
+(numeric_lit) @number
+
+(bool_lit) @boolean
+
+(null_lit) @constant
+
+(comment) @comment
+
+(identifier) @variable
+
+(body
+  (block
+    (identifier) @keyword))
+
+(body
+  (block
+    (body
+      (block
+        (identifier) @type))))
+
+(function_call
+  (identifier) @function)
+
+(attribute
+  (identifier) @variable)
+
+; { key: val }
+;
+; highlight identifier keys as though they were block attributes
+(object_elem
+  key:
+    (expression
+      (variable_expr
+        (identifier) @variable)))
+
+; var.foo, data.bar
+;
+; first element in get_attr is a variable.builtin or a reference to a variable.builtin
+(expression
+  (variable_expr
+    (identifier) @variable)
+  (get_attr
+    (identifier) @variable))
+
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/cb79d2446196d25607eb1d982c96939abdf67b8e/queries/terraform/highlights.scm
+; Terraform specific references
+;
+;
+; local/module/data/var/output
+(expression
+  (variable_expr
+    (identifier) @variable
+    (#any-of? @variable "data" "var" "local" "module" "output"))
+  (get_attr
+    (identifier) @variable))
+
+; path.root/cwd/module
+(expression
+  (variable_expr
+    (identifier) @type
+    (#eq? @type "path"))
+  (get_attr
+    (identifier) @variable
+    (#any-of? @variable "root" "cwd" "module")))
+
+; terraform.workspace
+(expression
+  (variable_expr
+    (identifier) @type
+    (#eq? @type "terraform"))
+  (get_attr
+    (identifier) @variable
+    (#any-of? @variable "workspace")))
+
+; Terraform specific keywords
+; FIXME: ideally only for identifiers under a `variable` block to minimize false positives
+((identifier) @type
+  (#any-of? @type "bool" "string" "number" "object" "tuple" "list" "map" "set" "any"))
+
+(object_elem
+  val:
+    (expression
+      (variable_expr
+        (identifier) @type
+        (#any-of? @type "bool" "string" "number" "object" "tuple" "list" "map" "set" "any"))))

extensions/terraform/languages/terraform-vars/indents.scm

@@ -0,0 +1,14 @@
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/hcl/indents.scm
+[
+  (block)
+  (object)
+  (tuple)
+  (function_call)
+] @indent
+
+(_ "[" "]" @end) @indent
+(_ "(" ")" @end) @indent
+(_ "{" "}" @end) @indent
+
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/terraform/indents.scm
+; inherits: hcl

extensions/terraform/languages/terraform-vars/injections.scm

@@ -0,0 +1,9 @@
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/hcl/injections.scm
+
+(heredoc_template
+  (template_literal) @content
+  (heredoc_identifier) @language
+  (#downcase! @language))
+
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/terraform/injections.scm
+; inherits: hcl

extensions/terraform/languages/terraform/config.toml

@@ -0,0 +1,15 @@
+name = "Terraform"
+grammar = "hcl"
+path_suffixes = ["tf"]
+line_comments = ["# ", "// "]
+block_comment = ["/*", "*/"]
+autoclose_before = ",}])"
+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 = false, not_in = ["comment", "string"] },
+    { start = "/*", end = " */", close = true, newline = false, not_in = ["comment", "string"] },
+]
+tab_size = 2

extensions/terraform/languages/terraform/highlights.scm

@@ -0,0 +1,159 @@
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/cb79d2446196d25607eb1d982c96939abdf67b8e/queries/hcl/highlights.scm
+; highlights.scm
+[
+  "!"
+  "\*"
+  "/"
+  "%"
+  "\+"
+  "-"
+  ">"
+  ">="
+  "<"
+  "<="
+  "=="
+  "!="
+  "&&"
+  "||"
+] @operator
+
+[
+  "{"
+  "}"
+  "["
+  "]"
+  "("
+  ")"
+] @punctuation.bracket
+
+[
+  "."
+  ".*"
+  ","
+  "[*]"
+] @punctuation.delimiter
+
+[
+  (ellipsis)
+  "\?"
+  "=>"
+] @punctuation.special
+
+[
+  ":"
+  "="
+] @punctuation
+
+[
+  "for"
+  "endfor"
+  "in"
+  "if"
+  "else"
+  "endif"
+] @keyword
+
+[
+  (quoted_template_start) ; "
+  (quoted_template_end) ; "
+  (template_literal) ; non-interpolation/directive content
+] @string
+
+[
+  (heredoc_identifier) ; END
+  (heredoc_start) ; << or <<-
+] @punctuation.delimiter
+
+[
+  (template_interpolation_start) ; ${
+  (template_interpolation_end) ; }
+  (template_directive_start) ; %{
+  (template_directive_end) ; }
+  (strip_marker) ; ~
+] @punctuation.special
+
+(numeric_lit) @number
+
+(bool_lit) @boolean
+
+(null_lit) @constant
+
+(comment) @comment
+
+(identifier) @variable
+
+(body
+  (block
+    (identifier) @keyword))
+
+(body
+  (block
+    (body
+      (block
+        (identifier) @type))))
+
+(function_call
+  (identifier) @function)
+
+(attribute
+  (identifier) @variable)
+
+; { key: val }
+;
+; highlight identifier keys as though they were block attributes
+(object_elem
+  key:
+    (expression
+      (variable_expr
+        (identifier) @variable)))
+
+; var.foo, data.bar
+;
+; first element in get_attr is a variable.builtin or a reference to a variable.builtin
+(expression
+  (variable_expr
+    (identifier) @variable)
+  (get_attr
+    (identifier) @variable))
+
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/cb79d2446196d25607eb1d982c96939abdf67b8e/queries/terraform/highlights.scm
+; Terraform specific references
+;
+;
+; local/module/data/var/output
+(expression
+  (variable_expr
+    (identifier) @variable
+    (#any-of? @variable "data" "var" "local" "module" "output"))
+  (get_attr
+    (identifier) @variable))
+
+; path.root/cwd/module
+(expression
+  (variable_expr
+    (identifier) @type
+    (#eq? @type "path"))
+  (get_attr
+    (identifier) @variable
+    (#any-of? @variable "root" "cwd" "module")))
+
+; terraform.workspace
+(expression
+  (variable_expr
+    (identifier) @type
+    (#eq? @type "terraform"))
+  (get_attr
+    (identifier) @variable
+    (#any-of? @variable "workspace")))
+
+; Terraform specific keywords
+; FIXME: ideally only for identifiers under a `variable` block to minimize false positives
+((identifier) @type
+  (#any-of? @type "bool" "string" "number" "object" "tuple" "list" "map" "set" "any"))
+
+(object_elem
+  val:
+    (expression
+      (variable_expr
+        (identifier) @type
+        (#any-of? @type "bool" "string" "number" "object" "tuple" "list" "map" "set" "any"))))

extensions/terraform/languages/terraform/indents.scm

@@ -0,0 +1,14 @@
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/hcl/indents.scm
+[
+  (block)
+  (object)
+  (tuple)
+  (function_call)
+] @indent
+
+(_ "[" "]" @end) @indent
+(_ "(" ")" @end) @indent
+(_ "{" "}" @end) @indent
+
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/terraform/indents.scm
+; inherits: hcl

extensions/terraform/languages/terraform/injections.scm

@@ -0,0 +1,9 @@
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/hcl/injections.scm
+
+(heredoc_template
+  (template_literal) @content
+  (heredoc_identifier) @language
+  (#downcase! @language))
+
+; https://github.com/nvim-treesitter/nvim-treesitter/blob/ce4adf11cfe36fc5b0e5bcdce0c7c6e8fbc9798a/queries/terraform/injections.scm
+; inherits: hcl

extensions/terraform/src/terraform.rs

@@ -0,0 +1,101 @@
+use std::fs;
+use zed::LanguageServerId;
+use zed_extension_api::{self as zed, Result};
+
+struct TerraformExtension {
+    cached_binary_path: Option<String>,
+}
+
+impl TerraformExtension {
+    fn language_server_binary_path(
+        &mut self,
+        language_server_id: &LanguageServerId,
+        worktree: &zed::Worktree,
+    ) -> Result<String> {
+        if let Some(path) = &self.cached_binary_path {
+            if fs::metadata(path).map_or(false, |stat| stat.is_file()) {
+                return Ok(path.clone());
+            }
+        }
+
+        if let Some(path) = worktree.which("terraform-ls") {
+            self.cached_binary_path = Some(path.clone());
+            return Ok(path);
+        }
+
+        zed::set_language_server_installation_status(
+            &language_server_id,
+            &zed::LanguageServerInstallationStatus::CheckingForUpdate,
+        );
+        let release = zed::latest_github_release(
+            "hashicorp/terraform-ls",
+            zed::GithubReleaseOptions {
+                require_assets: false,
+                pre_release: false,
+            },
+        )?;
+
+        let (platform, arch) = zed::current_platform();
+        let download_url = format!(
+            "https://releases.hashicorp.com/terraform-ls/{version}/terraform-ls_{version}_{os}_{arch}.zip",
+            version = release.version.strip_prefix('v').unwrap_or(&release.version),
+            os = match platform {
+                zed::Os::Mac => "darwin",
+                zed::Os::Linux => "linux",
+                zed::Os::Windows => "windows",
+            },
+            arch = match arch {
+                zed::Architecture::Aarch64 => "arm64",
+                zed::Architecture::X86 => "386",
+                zed::Architecture::X8664 => "amd64",
+            },
+        );
+
+        let version_dir = format!("terraform-ls-{}", release.version);
+        let binary_path = format!("{version_dir}/terraform-ls");
+
+        if !fs::metadata(&binary_path).map_or(false, |stat| stat.is_file()) {
+            zed::set_language_server_installation_status(
+                &language_server_id,
+                &zed::LanguageServerInstallationStatus::Downloading,
+            );
+
+            zed::download_file(&download_url, &version_dir, zed::DownloadedFileType::Zip)
+                .map_err(|e| format!("failed to download file: {e}"))?;
+
+            let entries =
+                fs::read_dir(".").map_err(|e| format!("failed to list working directory {e}"))?;
+            for entry in entries {
+                let entry = entry.map_err(|e| format!("failed to load directory entry {e}"))?;
+                if entry.file_name().to_str() != Some(&version_dir) {
+                    fs::remove_dir_all(&entry.path()).ok();
+                }
+            }
+        }
+
+        self.cached_binary_path = Some(binary_path.clone());
+        Ok(binary_path)
+    }
+}
+
+impl zed::Extension for TerraformExtension {
+    fn new() -> Self {
+        Self {
+            cached_binary_path: None,
+        }
+    }
+
+    fn language_server_command(
+        &mut self,
+        language_server_id: &LanguageServerId,
+        worktree: &zed::Worktree,
+    ) -> Result<zed::Command> {
+        Ok(zed::Command {
+            command: self.language_server_binary_path(language_server_id, worktree)?,
+            args: vec!["serve".to_string()],
+            env: Default::default(),
+        })
+    }
+}
+
+zed::register_extension!(TerraformExtension);