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]>

1 files changed, 12 insertions, 1 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()?;