astro: Ensure Typescript is present (#14849)

The current Astro Extension fails to load properly if it can't find a
`tsserver.js` file in the current workspaces' `node_modules` folder.
This happens pretty frequently, either if `typescript` is not installed
in the project (which it isn't by default), or if `node_modules` is not
in the workspace root.

This PR adds a fallback method of installing `typescript` alongside the
extensions' language server if it is not found in the workspaces'
`node_modules`, as well as correctly setting the `tsdk` path in the
initialization options.

Release Notes:

- N/A

---------

Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

Cargo.lock

@@ -13855,6 +13855,7 @@ dependencies = [
 name = "zed_astro"
 version = "0.0.3"
 dependencies = [
+ "serde",
  "zed_extension_api 0.0.6",
 ]
 

extensions/astro/Cargo.toml

@@ -13,4 +13,5 @@ path = "src/astro.rs"
 crate-type = ["cdylib"]
 
 [dependencies]
+serde = { version = "1.0", features = ["derive"] }
 zed_extension_api = "0.0.6"

extensions/astro/extension.toml

@@ -3,7 +3,7 @@ name = "Astro"
 description = "Astro support."
 version = "0.0.3"
 schema_version = 1
-authors = ["Alvaro Gaona <alvgaona@gmail.com>"]
+authors = ["Alvaro Gaona <alvgaona@gmail.com>", "0xk1f0 <dev@k1f0.dev>"]
 repository = "https://github.com/zed-industries/zed"
 
 [language_servers.astro-language-server]

extensions/astro/src/astro.rs

@@ -1,11 +1,29 @@
+use std::collections::HashMap;
 use std::{env, fs};
+
+use serde::Deserialize;
 use zed_extension_api::{self as zed, serde_json, Result};
 
 const SERVER_PATH: &str = "node_modules/@astrojs/language-server/bin/nodeServer.js";
 const PACKAGE_NAME: &str = "@astrojs/language-server";
 
+const TYPESCRIPT_PACKAGE_NAME: &str = "typescript";
+
+/// The relative path to TypeScript's SDK.
+const TYPESCRIPT_TSDK_PATH: &str = "node_modules/typescript/lib";
+
+#[derive(Debug, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct PackageJson {
+    #[serde(default)]
+    dependencies: HashMap<String, String>,
+    #[serde(default)]
+    dev_dependencies: HashMap<String, String>,
+}
+
 struct AstroExtension {
     did_find_server: bool,
+    typescript_tsdk_path: String,
 }
 
 impl AstroExtension {
@@ -13,9 +31,14 @@ impl AstroExtension {
         fs::metadata(SERVER_PATH).map_or(false, |stat| stat.is_file())
     }
 
-    fn server_script_path(&mut self, language_server_id: &zed::LanguageServerId) -> Result<String> {
+    fn server_script_path(
+        &mut self,
+        language_server_id: &zed::LanguageServerId,
+        worktree: &zed::Worktree,
+    ) -> Result<String> {
         let server_exists = self.server_exists();
         if self.did_find_server && server_exists {
+            self.install_typescript_if_needed(worktree)?;
             return Ok(SERVER_PATH.to_string());
         }
 
@@ -49,24 +72,71 @@ impl AstroExtension {
             }
         }
 
+        self.install_typescript_if_needed(worktree)?;
         self.did_find_server = true;
         Ok(SERVER_PATH.to_string())
     }
+
+    /// Returns whether a local copy of TypeScript exists in the worktree.
+    fn typescript_exists_for_worktree(&self, worktree: &zed::Worktree) -> Result<bool> {
+        let package_json = worktree.read_text_file("package.json")?;
+        let package_json: PackageJson = serde_json::from_str(&package_json)
+            .map_err(|err| format!("failed to parse package.json: {err}"))?;
+
+        let dev_dependencies = &package_json.dev_dependencies;
+        let dependencies = &package_json.dependencies;
+
+        // Since the extension is not allowed to read the filesystem within the project
+        // except through the worktree (which does not contains `node_modules`), we check
+        // the `package.json` to see if `typescript` is listed in the dependencies.
+        Ok(dev_dependencies.contains_key(TYPESCRIPT_PACKAGE_NAME)
+            || dependencies.contains_key(TYPESCRIPT_PACKAGE_NAME))
+    }
+
+    fn install_typescript_if_needed(&mut self, worktree: &zed::Worktree) -> Result<()> {
+        if self
+            .typescript_exists_for_worktree(worktree)
+            .unwrap_or_default()
+        {
+            println!("found local TypeScript installation at '{TYPESCRIPT_TSDK_PATH}'");
+            return Ok(());
+        }
+
+        let installed_typescript_version =
+            zed::npm_package_installed_version(TYPESCRIPT_PACKAGE_NAME)?;
+        let latest_typescript_version = zed::npm_package_latest_version(TYPESCRIPT_PACKAGE_NAME)?;
+
+        if installed_typescript_version.as_ref() != Some(&latest_typescript_version) {
+            println!("installing {TYPESCRIPT_PACKAGE_NAME}@{latest_typescript_version}");
+            zed::npm_install_package(TYPESCRIPT_PACKAGE_NAME, &latest_typescript_version)?;
+        } else {
+            println!("typescript already installed");
+        }
+
+        self.typescript_tsdk_path = env::current_dir()
+            .unwrap()
+            .join(TYPESCRIPT_TSDK_PATH)
+            .to_string_lossy()
+            .to_string();
+
+        Ok(())
+    }
 }
 
 impl zed::Extension for AstroExtension {
     fn new() -> Self {
         Self {
             did_find_server: false,
+            typescript_tsdk_path: TYPESCRIPT_TSDK_PATH.to_owned(),
         }
     }
 
     fn language_server_command(
         &mut self,
         language_server_id: &zed::LanguageServerId,
-        _worktree: &zed::Worktree,
+        worktree: &zed::Worktree,
     ) -> Result<zed::Command> {
-        let server_path = self.server_script_path(language_server_id)?;
+        let server_path = self.server_script_path(language_server_id, worktree)?;
         Ok(zed::Command {
             command: zed::node_binary_path()?,
             args: vec![
@@ -89,7 +159,7 @@ impl zed::Extension for AstroExtension {
         Ok(Some(serde_json::json!({
             "provideFormatter": true,
             "typescript": {
-                "tsdk": "node_modules/typescript/lib"
+                "tsdk": self.typescript_tsdk_path
             }
         })))
     }