Add yaml language server

crates/zed/src/languages.rs

@@ -14,8 +14,8 @@ mod lua;
 mod python;
 mod ruby;
 mod rust;
-
 mod typescript;
+mod yaml;
 
 // 1. Add tree-sitter-{language} parser to zed crate
 // 2. Create a language directory in zed/crates/zed/src/languages and add the language to init function below
@@ -131,8 +131,8 @@ pub fn init(languages: Arc<LanguageRegistry>) {
         (
             "yaml",
             tree_sitter_yaml::language(),
-            None, //
+            Some(Box::new(yaml::YamlLspAdapter)),
-        )
+        ),
     ] {
         languages.register(name, load_config(name), grammar, lsp_adapter, load_queries);
     }

crates/zed/src/languages/yaml.rs

@@ -0,0 +1,94 @@
+use std::{any::Any, path::PathBuf, sync::Arc};
+
+use anyhow::{anyhow, Context, Result};
+use async_trait::async_trait;
+use client::http::HttpClient;
+use futures::StreamExt;
+use serde_json::json;
+use smol::fs;
+
+use language::{LanguageServerName, LspAdapter};
+use util::ResultExt;
+
+use super::installation::{npm_install_packages, npm_package_latest_version};
+
+pub struct YamlLspAdapter;
+
+impl YamlLspAdapter {
+    const BIN_PATH: &'static str = "node_modules/yaml-language-server/bin/yaml-language-server";
+}
+
+#[async_trait]
+impl LspAdapter for YamlLspAdapter {
+    async fn name(&self) -> LanguageServerName {
+        LanguageServerName("yaml-language-server".into())
+    }
+
+    async fn server_args(&self) -> Vec<String> {
+        vec!["--stdio".into()]
+    }
+
+    async fn fetch_latest_server_version(
+        &self,
+        _: Arc<dyn HttpClient>,
+    ) -> Result<Box<dyn 'static + Any + Send>> {
+        Ok(Box::new(npm_package_latest_version("yaml-language-server").await?) as Box<_>)
+    }
+
+    async fn fetch_server_binary(
+        &self,
+        version: Box<dyn 'static + Send + Any>,
+        _: Arc<dyn HttpClient>,
+        container_dir: PathBuf,
+    ) -> Result<PathBuf> {
+        let version = version.downcast::<String>().unwrap();
+        let version_dir = container_dir.join(version.as_str());
+        fs::create_dir_all(&version_dir)
+            .await
+            .context("failed to create version directory")?;
+        let binary_path = version_dir.join(Self::BIN_PATH);
+
+        if fs::metadata(&binary_path).await.is_err() {
+            npm_install_packages([("yaml-language-server", version.as_str())], &version_dir)
+                .await?;
+
+            if let Some(mut entries) = fs::read_dir(&container_dir).await.log_err() {
+                while let Some(entry) = entries.next().await {
+                    if let Some(entry) = entry.log_err() {
+                        let entry_path = entry.path();
+                        if entry_path.as_path() != version_dir {
+                            fs::remove_dir_all(&entry_path).await.log_err();
+                        }
+                    }
+                }
+            }
+        }
+
+        Ok(binary_path)
+    }
+
+    async fn cached_server_binary(&self, container_dir: PathBuf) -> Option<PathBuf> {
+        (|| async move {
+            let mut last_version_dir = None;
+            let mut entries = fs::read_dir(&container_dir).await?;
+            while let Some(entry) = entries.next().await {
+                let entry = entry?;
+                if entry.file_type().await?.is_dir() {
+                    last_version_dir = Some(entry.path());
+                }
+            }
+            let last_version_dir = last_version_dir.ok_or_else(|| anyhow!("no cached binary"))?;
+            let bin_path = last_version_dir.join(Self::BIN_PATH);
+            if bin_path.exists() {
+                Ok(bin_path)
+            } else {
+                Err(anyhow!(
+                    "missing executable in directory {:?}",
+                    last_version_dir
+                ))
+            }
+        })()
+        .await
+        .log_err()
+    }
+}