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]>

2 files changed, 2 insertions, 8 deletions

diff --git a/editors/code/src/commands/runnables.ts b/editors/code/src/commands/runnables.ts
index 3589edcee..c4df24c79 100644
--- a/editors/code/src/commands/runnables.ts
+++ b/editors/code/src/commands/runnables.ts
@@ -17,6 +17,7 @@ interface Runnable {
     bin: string;
     args: string[];
     env: { [index: string]: string };
+    cwd?: string;
 }
 
 class RunnableQuickPick implements vscode.QuickPickItem {
@@ -49,7 +50,7 @@ function createTask(spec: Runnable): vscode.Task {
     };
 
     const execOption: vscode.ShellExecutionOptions = {
-        cwd: '.',
+        cwd: spec.cwd || '.',
         env: definition.env
     };
     const exec = new vscode.ShellExecution(
diff --git a/editors/code/src/server.ts b/editors/code/src/server.ts
index f319f148a..5e9a19340 100644
--- a/editors/code/src/server.ts
+++ b/editors/code/src/server.ts
@@ -17,13 +17,6 @@ export class Server {
         let folder: string = '.';
         if (workspace.workspaceFolders !== undefined) {
             folder = workspace.workspaceFolders[0].uri.fsPath.toString();
-
-            if (workspace.workspaceFolders.length > 1) {
-                // Tell the user that we do not support multi-root workspaces yet
-                window.showWarningMessage(
-                    'Multi-root workspaces are not currently supported'
-                );
-            }
         }
 
         const run: lc.Executable = {