Integrate pyright language server

crates/zed/src/languages/python.rs

@@ -0,0 +1,97 @@
+use super::installation::{npm_install_packages, npm_package_latest_version};
+use anyhow::{anyhow, Context, Result};
+use client::http::HttpClient;
+use futures::{future::BoxFuture, FutureExt, StreamExt};
+use language::{LanguageServerName, LspAdapter};
+use smol::fs;
+use std::{
+    any::Any,
+    path::{Path, PathBuf},
+    sync::Arc,
+};
+use util::{ResultExt, TryFutureExt};
+
+pub struct PythonLspAdapter;
+
+impl PythonLspAdapter {
+    const BIN_PATH: &'static str = "node_modules/pyright/langserver.index.js";
+}
+
+impl LspAdapter for PythonLspAdapter {
+    fn name(&self) -> LanguageServerName {
+        LanguageServerName("pyright".into())
+    }
+
+    fn server_args(&self) -> &[&str] {
+        &["--stdio"]
+    }
+
+    fn fetch_latest_server_version(
+        &self,
+        _: Arc<dyn HttpClient>,
+    ) -> BoxFuture<'static, Result<Box<dyn 'static + Any + Send>>> {
+        async move { Ok(Box::new(npm_package_latest_version("pyright").await?) as Box<_>) }.boxed()
+    }
+
+    fn fetch_server_binary(
+        &self,
+        version: Box<dyn 'static + Send + Any>,
+        _: Arc<dyn HttpClient>,
+        container_dir: Arc<Path>,
+    ) -> BoxFuture<'static, Result<PathBuf>> {
+        let version = version.downcast::<String>().unwrap();
+        async move {
+            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([("pyright", 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)
+        }
+        .boxed()
+    }
+
+    fn cached_server_binary(
+        &self,
+        container_dir: Arc<Path>,
+    ) -> BoxFuture<'static, 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
+                ))
+            }
+        }
+        .log_err()
+        .boxed()
+    }
+}