Change enableCargoWatchOnStartup to have three states

This fixes #1005.

Defaults to `ask` which prompts users each time whether to start `cargo watch`
or not. `enabled` always starts `cargo watch` and `disabled` does not.

3 files changed, 31 insertions, 16 deletions

diff --git a/editors/code/package.json b/editors/code/package.json
index 3e8cde388..facb633d9 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -169,9 +169,19 @@
                     "description": "Path to ra_lsp_server executable"
                 },
                 "rust-analyzer.enableCargoWatchOnStartup": {
-                    "type": "boolean",
-                    "default": "true",
-                    "description": "When enabled, ask the user whether to run `cargo watch` on startup"
+                    "type": "string",
+                    "default": "ask",
+                    "enum": [
+                        "ask",
+                        "enabled",
+                        "disabled"
+                    ],
+                    "enumDescriptions": [
+                        "Asks each time whether to run `cargo watch`",
+                        "`cargo watch` is always started",
+                        "Don't start `cargo watch`"
+                    ],
+                    "description": "Whether to run `cargo watch` on startup"
                 },
                 "rust-analyzer.trace.server": {
                     "type": "string",
diff --git a/editors/code/src/commands/runnables.ts b/editors/code/src/commands/runnables.ts
index ea2883ad4..420635f41 100644
--- a/editors/code/src/commands/runnables.ts
+++ b/editors/code/src/commands/runnables.ts
@@ -153,22 +153,25 @@ export const autoCargoWatchTask: vscode.Task = {
  * that, when accepted, allow us to `cargo install cargo-watch` and then run it.
  */
 export async function interactivelyStartCargoWatch() {
-    if (!Server.config.enableCargoWatchOnStartup) {
+    if (Server.config.enableCargoWatchOnStartup === 'disabled') {
         return;
     }
 
-    const execPromise = util.promisify(child_process.exec);
-
-    const watch = await vscode.window.showInformationMessage(
-        'Start watching changes with cargo? (Executes `cargo watch`, provides inline diagnostics)',
-        'yes',
-        'no'
-    );
-    if (watch === 'no') {
-        return;
+    if (Server.config.enableCargoWatchOnStartup === 'ask') {
+        const watch = await vscode.window.showInformationMessage(
+            'Start watching changes with cargo? (Executes `cargo watch`, provides inline diagnostics)',
+            'yes',
+            'no'
+        );
+        if (watch === 'no') {
+            return;
+        }
     }
 
+    const execPromise = util.promisify(child_process.exec);
+
     const { stderr } = await execPromise('cargo watch --version').catch(e => e);
+
     if (stderr.includes('no such subcommand: `watch`')) {
         const msg =
             'The `cargo-watch` subcommand is not installed. Install? (takes ~1-2 minutes)';
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index d8795f3b0..420589068 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -4,12 +4,14 @@ import { Server } from './server';
 
 const RA_LSP_DEBUG = process.env.__RA_LSP_SERVER_DEBUG;
 
+export type CargoWatchOptions = 'ask' | 'enabled' | 'disabled';
+
 export class Config {
     public highlightingOn = true;
     public enableEnhancedTyping = true;
     public raLspServerPath = RA_LSP_DEBUG || 'ra_lsp_server';
     public showWorkspaceLoadedNotification = true;
-    public enableCargoWatchOnStartup = true;
+    public enableCargoWatchOnStartup: CargoWatchOptions = 'ask';
 
     private prevEnhancedTyping: null | boolean = null;
 
@@ -71,9 +73,9 @@ export class Config {
         }
 
         if (config.has('enableCargoWatchOnStartup')) {
-            this.enableCargoWatchOnStartup = config.get<boolean>(
+            this.enableCargoWatchOnStartup = config.get<CargoWatchOptions>(
                 'enableCargoWatchOnStartup',
-                true
+                'ask'
             );
         }
     }