Merge #1137

1137: Adds support for multiple editor workspaces on initialization r=matklad a=jrvidal

OK, so this "simple hack" turned out to be way more contrived than I expected :joy:

### What works
This patch only handles multi-folder editor workspaces _on initialization_.
  * I've found that modifying the layout of a workspace in VSCode just reloads the extension, so this hack should be enough for now.
  * Not sure about how emacs-lsp behaves, but we fallback gracefully to the mono-folder workspace, so it should be fine.

### What doesn't work
* [x] `cargo watch` can only watch a single root folder with a `Cargo.toml`. I've left this part untouched but we could either warn that it's not supported or launch _multiple_ `cargo-watch` processes.
* [x] The `rust-analyzer/runnables` command is not functional, since we don't send the correct `cwd`.
* [x] Should we add some happy path test to `heavy_tests`?
* [ ] Going from a single `root` to multiple `roots` leaves us with a couple of `n * m` loops that smell a bit. The number of folders in the editor workspace is probably low though.

Co-authored-by: Roberto Vidal <[email protected]>

9 files changed, 142 insertions, 55 deletions

diff --git a/crates/ra_lsp_server/src/main.rs b/crates/ra_lsp_server/src/main.rs
index eb4091a3d..82f52a6e8 100644
--- a/crates/ra_lsp_server/src/main.rs
+++ b/crates/ra_lsp_server/src/main.rs
@@ -40,12 +40,23 @@ fn main_inner() -> Result<()> {
     run_server(ra_lsp_server::server_capabilities(), receiver, sender, |params, r, s| {
         let root = params.root_uri.and_then(|it| it.to_file_path().ok()).unwrap_or(cwd);
 
+        let workspace_roots = params
+            .workspace_folders
+            .map(|workspaces| {
+                workspaces
+                    .into_iter()
+                    .filter_map(|it| it.uri.to_file_path().ok())
+                    .collect::<Vec<_>>()
+            })
+            .filter(|workspaces| !workspaces.is_empty())
+            .unwrap_or_else(|| vec![root]);
+
         let opts = params
             .initialization_options
             .and_then(|v| InitializationOptions::deserialize(v).ok())
             .unwrap_or(InitializationOptions::default());
 
-        ra_lsp_server::main_loop(root, opts, r, s)
+        ra_lsp_server::main_loop(workspace_roots, opts, r, s)
     })?;
     log::info!("shutting down IO...");
     threads.join()?;
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 82410bee3..07ac4917a 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -48,7 +48,7 @@ enum Task {
 const THREADPOOL_SIZE: usize = 8;
 
 pub fn main_loop(
-    ws_root: PathBuf,
+    ws_roots: Vec<PathBuf>,
     options: InitializationOptions,
     msg_receiver: &Receiver<RawMessage>,
     msg_sender: &Sender<RawMessage>,
@@ -59,23 +59,26 @@ pub fn main_loop(
     // FIXME: support dynamic workspace loading.
     let workspaces = {
         let ws_worker = workspace_loader();
-        ws_worker.sender().send(ws_root.clone()).unwrap();
-        match ws_worker.receiver().recv().unwrap() {
-            Ok(ws) => vec![ws],
-            Err(e) => {
-                log::error!("loading workspace failed: {}", e);
-
-                show_message(
-                    req::MessageType::Error,
-                    format!("rust-analyzer failed to load workspace: {}", e),
-                    msg_sender,
-                );
-                Vec::new()
+        let mut loaded_workspaces = Vec::new();
+        for ws_root in &ws_roots {
+            ws_worker.sender().send(ws_root.clone()).unwrap();
+            match ws_worker.receiver().recv().unwrap() {
+                Ok(ws) => loaded_workspaces.push(ws),
+                Err(e) => {
+                    log::error!("loading workspace failed: {}", e);
+
+                    show_message(
+                        req::MessageType::Error,
+                        format!("rust-analyzer failed to load workspace: {}", e),
+                        msg_sender,
+                    );
+                }
             }
         }
+        loaded_workspaces
     };
 
-    let mut state = ServerWorldState::new(ws_root.clone(), workspaces);
+    let mut state = ServerWorldState::new(ws_roots, workspaces);
 
     log::info!("server initialized, serving requests");
 
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index b96deb061..41d1f759f 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -263,6 +263,7 @@ pub fn handle_runnables(
     let line_index = world.analysis().file_line_index(file_id);
     let offset = params.position.map(|it| it.conv_with(&line_index));
     let mut res = Vec::new();
+    let workspace_root = world.workspace_root_for(file_id);
     for runnable in world.analysis().runnables(file_id)? {
         if let Some(offset) = offset {
             if !runnable.range.contains_inclusive(offset) {
@@ -287,6 +288,7 @@ pub fn handle_runnables(
                 m.insert("RUST_BACKTRACE".to_string(), "short".to_string());
                 m
             },
+            cwd: workspace_root.map(|root| root.to_string_lossy().to_string()),
         };
         res.push(r);
     }
@@ -309,6 +311,7 @@ pub fn handle_runnables(
         bin: "cargo".to_string(),
         args: check_args,
         env: FxHashMap::default(),
+        cwd: workspace_root.map(|root| root.to_string_lossy().to_string()),
     });
     Ok(res)
 }
@@ -627,6 +630,7 @@ pub fn handle_code_lens(
     let line_index = world.analysis().file_line_index(file_id);
 
     let mut lenses: Vec<CodeLens> = Default::default();
+    let workspace_root = world.workspace_root_for(file_id);
 
     // Gather runnables
     for runnable in world.analysis().runnables(file_id)? {
@@ -647,6 +651,7 @@ pub fn handle_code_lens(
                 bin: "cargo".into(),
                 args,
                 env: Default::default(),
+                cwd: workspace_root.map(|root| root.to_string_lossy().to_string()),
             };
 
             let lens = CodeLens {
diff --git a/crates/ra_lsp_server/src/req.rs b/crates/ra_lsp_server/src/req.rs
index e0571fd78..4f35ab9b5 100644
--- a/crates/ra_lsp_server/src/req.rs
+++ b/crates/ra_lsp_server/src/req.rs
@@ -163,6 +163,7 @@ pub struct Runnable {
     pub bin: String,
     pub args: Vec<String>,
     pub env: FxHashMap<String, String>,
+    pub cwd: Option<String>,
 }
 
 #[derive(Serialize, Debug)]
diff --git a/crates/ra_lsp_server/src/server_world.rs b/crates/ra_lsp_server/src/server_world.rs
index 4b1d592bb..b2808b817 100644
--- a/crates/ra_lsp_server/src/server_world.rs
+++ b/crates/ra_lsp_server/src/server_world.rs
@@ -1,5 +1,5 @@
 use std::{
-    path::PathBuf,
+    path::{Path, PathBuf},
     sync::Arc,
 };
 
@@ -24,7 +24,7 @@ use crate::{
 #[derive(Debug)]
 pub struct ServerWorldState {
     pub roots_to_scan: usize,
-    pub root: PathBuf,
+    pub roots: Vec<PathBuf>,
     pub workspaces: Arc<Vec<ProjectWorkspace>>,
     pub analysis_host: AnalysisHost,
     pub vfs: Arc<RwLock<Vfs>>,
@@ -37,19 +37,20 @@ pub struct ServerWorld {
 }
 
 impl ServerWorldState {
-    pub fn new(root: PathBuf, workspaces: Vec<ProjectWorkspace>) -> ServerWorldState {
+    pub fn new(folder_roots: Vec<PathBuf>, workspaces: Vec<ProjectWorkspace>) -> ServerWorldState {
         let mut change = AnalysisChange::new();
 
         let mut roots = Vec::new();
-        roots.push(IncludeRustFiles::member(root.clone()));
+        roots.extend(folder_roots.iter().cloned().map(IncludeRustFiles::member));
         for ws in workspaces.iter() {
             roots.extend(IncludeRustFiles::from_roots(ws.to_roots()));
         }
 
-        let (mut vfs, roots) = Vfs::new(roots);
-        let roots_to_scan = roots.len();
-        for r in roots {
-            let is_local = vfs.root2path(r).starts_with(&root);
+        let (mut vfs, vfs_roots) = Vfs::new(roots);
+        let roots_to_scan = vfs_roots.len();
+        for r in vfs_roots {
+            let vfs_root_path = vfs.root2path(r);
+            let is_local = folder_roots.iter().any(|it| vfs_root_path.starts_with(it));
             change.add_root(SourceRootId(r.0.into()), is_local);
         }
 
@@ -68,7 +69,7 @@ impl ServerWorldState {
         analysis_host.apply_change(change);
         ServerWorldState {
             roots_to_scan,
-            root,
+            roots: folder_roots,
             workspaces: Arc::new(workspaces),
             analysis_host,
             vfs: Arc::new(RwLock::new(vfs)),
@@ -90,7 +91,8 @@ impl ServerWorldState {
             match c {
                 VfsChange::AddRoot { root, files } => {
                     let root_path = self.vfs.read().root2path(root);
-                    if root_path.starts_with(&self.root) {
+                    let is_local = self.roots.iter().any(|r| root_path.starts_with(r));
+                    if is_local {
                         self.roots_to_scan -= 1;
                         for (file, path, text) in files {
                             change.add_file(
@@ -193,4 +195,9 @@ impl ServerWorld {
         res.push_str(&self.analysis.status());
         res
     }
+
+    pub fn workspace_root_for(&self, file_id: FileId) -> Option<&Path> {
+        let path = self.vfs.read().file2path(VfsFile(file_id.0.into()));
+        self.workspaces.iter().find_map(|ws| ws.workspace_root_for(&path))
+    }
 }
diff --git a/crates/ra_lsp_server/tests/heavy_tests/main.rs b/crates/ra_lsp_server/tests/heavy_tests/main.rs
index 407719080..6f37a980d 100644
--- a/crates/ra_lsp_server/tests/heavy_tests/main.rs
+++ b/crates/ra_lsp_server/tests/heavy_tests/main.rs
@@ -14,7 +14,7 @@ use ra_lsp_server::req::{
 use serde_json::json;
 use tempfile::TempDir;
 
-use crate::support::{project, project_with_tmpdir};
+use crate::support::{project, Project};
 
 const LOG: &'static str = "";
 
@@ -62,6 +62,7 @@ fn foo() {
             "args": [ "test", "--", "foo", "--nocapture" ],
             "bin": "cargo",
             "env": { "RUST_BACKTRACE": "short" },
+            "cwd": null,
             "label": "test foo",
             "range": {
               "end": { "character": 1, "line": 2 },
@@ -75,6 +76,7 @@ fn foo() {
             ],
             "bin": "cargo",
             "env": {},
+            "cwd": null,
             "label": "cargo check --all",
             "range": {
               "end": {
@@ -93,25 +95,34 @@ fn foo() {
 
 #[test]
 fn test_runnables_project() {
-    let server = project(
-        r#"
-//- Cargo.toml
+    let code = r#"
+//- foo/Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
 
-//- src/lib.rs
+//- foo/src/lib.rs
 pub fn foo() {}
 
-//- tests/spam.rs
+//- foo/tests/spam.rs
 #[test]
 fn test_eggs() {}
-"#,
-    );
+
+//- bar/Cargo.toml
+[package]
+name = "bar"
+version = "0.0.0"
+
+//- bar/src/main.rs
+fn main() {}
+"#;
+
+    let server = Project::with_fixture(code).root("foo").root("bar").server();
+
     server.wait_until_workspace_is_loaded();
     server.request::<Runnables>(
         RunnablesParams {
-            text_document: server.doc_id("tests/spam.rs"),
+            text_document: server.doc_id("foo/tests/spam.rs"),
             position: None,
         },
         json!([
@@ -123,7 +134,8 @@ fn test_eggs() {}
             "range": {
               "end": { "character": 17, "line": 1 },
               "start": { "character": 0, "line": 0 }
-            }
+            },
+            "cwd": server.path().join("foo")
           },
           {
             "args": [
@@ -135,6 +147,7 @@ fn test_eggs() {}
             ],
             "bin": "cargo",
             "env": {},
+            "cwd": server.path().join("foo"),
             "label": "cargo check -p foo",
             "range": {
               "end": {
@@ -283,7 +296,9 @@ fn main() {{}}
 "#,
         PROJECT = project.to_string(),
     );
-    let server = project_with_tmpdir(tmp_dir, &code);
+
+    let server = Project::with_fixture(&code).tmp_dir(tmp_dir).server();
+
     server.wait_until_workspace_is_loaded();
     let empty_context = || CodeActionContext { diagnostics: Vec::new(), only: None };
     server.request::<CodeActionRequest>(
diff --git a/crates/ra_lsp_server/tests/heavy_tests/support.rs b/crates/ra_lsp_server/tests/heavy_tests/support.rs
index ab9db3dd4..b07882700 100644
--- a/crates/ra_lsp_server/tests/heavy_tests/support.rs
+++ b/crates/ra_lsp_server/tests/heavy_tests/support.rs
@@ -1,7 +1,7 @@
 use std::{
     cell::{Cell, RefCell},
     fs,
-    path::PathBuf,
+    path::{Path, PathBuf},
     sync::Once,
     time::Duration,
 };
@@ -26,26 +26,51 @@ use ra_lsp_server::{
     InitializationOptions,
 };
 
-pub fn project(fixture: &str) -> Server {
-    let tmp_dir = TempDir::new().unwrap();
-    project_with_tmpdir(tmp_dir, fixture)
+pub struct Project<'a> {
+    fixture: &'a str,
+    tmp_dir: Option<TempDir>,
+    roots: Vec<PathBuf>,
 }
 
-pub fn project_with_tmpdir(tmp_dir: TempDir, fixture: &str) -> Server {
-    static INIT: Once = Once::new();
-    INIT.call_once(|| {
-        let _ = Logger::with_env_or_str(crate::LOG).start().unwrap();
-    });
+impl<'a> Project<'a> {
+    pub fn with_fixture(fixture: &str) -> Project {
+        Project { fixture, tmp_dir: None, roots: vec![] }
+    }
 
-    let mut paths = vec![];
+    pub fn tmp_dir(mut self, tmp_dir: TempDir) -> Project<'a> {
+        self.tmp_dir = Some(tmp_dir);
+        self
+    }
 
-    for entry in parse_fixture(fixture) {
-        let path = tmp_dir.path().join(entry.meta);
-        fs::create_dir_all(path.parent().unwrap()).unwrap();
-        fs::write(path.as_path(), entry.text.as_bytes()).unwrap();
-        paths.push((path, entry.text));
+    pub fn root(mut self, path: &str) -> Project<'a> {
+        self.roots.push(path.into());
+        self
     }
-    Server::new(tmp_dir, paths)
+
+    pub fn server(self) -> Server {
+        let tmp_dir = self.tmp_dir.unwrap_or_else(|| TempDir::new().unwrap());
+        static INIT: Once = Once::new();
+        INIT.call_once(|| {
+            let _ = Logger::with_env_or_str(crate::LOG).start().unwrap();
+        });
+
+        let mut paths = vec![];
+
+        for entry in parse_fixture(self.fixture) {
+            let path = tmp_dir.path().join(entry.meta);
+            fs::create_dir_all(path.parent().unwrap()).unwrap();
+            fs::write(path.as_path(), entry.text.as_bytes()).unwrap();
+            paths.push((path, entry.text));
+        }
+
+        let roots = self.roots.into_iter().map(|root| tmp_dir.path().join(root)).collect();
+
+        Server::new(tmp_dir, roots, paths)
+    }
+}
+
+pub fn project(fixture: &str) -> Server {
+    Project::with_fixture(fixture).server()
 }
 
 pub struct Server {
@@ -56,14 +81,17 @@ pub struct Server {
 }
 
 impl Server {
-    fn new(dir: TempDir, files: Vec<(PathBuf, String)>) -> Server {
+    fn new(dir: TempDir, roots: Vec<PathBuf>, files: Vec<(PathBuf, String)>) -> Server {
         let path = dir.path().to_path_buf();
+
+        let roots = if roots.is_empty() { vec![path] } else { roots };
+
         let worker = Worker::<RawMessage, RawMessage>::spawn(
             "test server",
             128,
             move |mut msg_receiver, mut msg_sender| {
                 main_loop(
-                    path,
+                    roots,
                     InitializationOptions::default(),
                     &mut msg_receiver,
                     &mut msg_sender,
@@ -177,6 +205,10 @@ impl Server {
     fn send_notification(&self, not: RawNotification) {
         self.worker.as_ref().unwrap().sender().send(RawMessage::Notification(not)).unwrap();
     }
+
+    pub fn path(&self) -> &Path {
+        self.dir.path()
+    }
 }
 
 impl Drop for Server {
diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index 81cb506b7..71976071f 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -19,6 +19,7 @@ use crate::Result;
 pub struct CargoWorkspace {
     packages: Arena<Package, PackageData>,
     targets: Arena<Target, TargetData>,
+    pub(crate) workspace_root: PathBuf,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
@@ -165,7 +166,7 @@ impl CargoWorkspace {
             }
         }
 
-        Ok(CargoWorkspace { packages, targets })
+        Ok(CargoWorkspace { packages, targets, workspace_root: meta.workspace_root })
     }
 
     pub fn packages<'a>(&'a self) -> impl Iterator<Item = Package> + 'a {
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 3bad4f8d3..63eb7041e 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -255,6 +255,18 @@ impl ProjectWorkspace {
         }
         crate_graph
     }
+
+    pub fn workspace_root_for(&self, path: &Path) -> Option<&Path> {
+        match self {
+            ProjectWorkspace::Cargo { cargo, .. } => {
+                Some(cargo.workspace_root.as_ref()).filter(|root| path.starts_with(root))
+            }
+            ProjectWorkspace::Json { project: JsonProject { roots, .. } } => roots
+                .iter()
+                .find(|root| path.starts_with(&root.path))
+                .map(|root| root.path.as_ref()),
+        }
+    }
 }
 
 fn find_rust_project_json(path: &Path) -> Option<PathBuf> {