Auto merge of #15830 - davidbarsky:davidbarsky/allow-companion-extension-to-call-rust-analyzer, r=davidbarsky

code: expose workspaces to other extensions; remove `addProject` command

This (mostly red) PR does three things:
- Exposes two methods to companion extensions (`setWorkspaces` and `notifyRustAnalyzer`).
    - `setWorkspaces` is needed to update `linkedProjects` _without_ writing workspace/global configuration.
    - `notifyRustAnalyzer` to get the server to pull the new configuration.
- Makes `Ctx` implement `RustAnalyzerExtensionApi` to prevent accidental regressions.
- Remove `rust-analyzer.addProject`, as that will live in a buck2 companion extension. No need for that to be in rust-analyzer!

I can see the utility of combining `notifyRustAnalyzer` and `setWorkspaces` into a single method (`updateWorkspacesAndNotify()`?), but I don't feel strongly about this. My feeling is that this API could be easily changed in the future.

editors/code/package.json

@@ -209,11 +209,6 @@
                 "title": "Rebuild proc macros and build scripts",
                 "category": "rust-analyzer"
             },
-            {
-                "command": "rust-analyzer.addProject",
-                "title": "Add current file's crate to workspace",
-                "category": "rust-analyzer"
-            },
             {
                 "command": "rust-analyzer.restartServer",
                 "title": "Restart server",

editors/code/src/commands.ts

@@ -870,28 +870,6 @@ export function rebuildProcMacros(ctx: CtxInit): Cmd {
     return async () => ctx.client.sendRequest(ra.rebuildProcMacros);
 }
 
-export function addProject(ctx: CtxInit): Cmd {
-    return async () => {
-        const extensionName = ctx.config.discoverProjectRunner;
-        // this command shouldn't be enabled in the first place if this isn't set.
-        if (!extensionName) {
-            return;
-        }
-
-        const command = `${extensionName}.discoverWorkspaceCommand`;
-        const project: JsonProject = await vscode.commands.executeCommand(command);
-
-        ctx.addToDiscoveredWorkspaces([project]);
-
-        // this is a workaround to avoid needing writing the `rust-project.json` into
-        // a workspace-level VS Code-specific settings folder. We'd like to keep the
-        // `rust-project.json` entirely in-memory.
-        await ctx.client?.sendNotification(lc.DidChangeConfigurationNotification.type, {
-            settings: "",
-        });
-    };
-}
-
 async function showReferencesImpl(
     client: LanguageClient | undefined,
     uri: string,

editors/code/src/ctx.ts

@@ -1,5 +1,5 @@
 import * as vscode from "vscode";
-import type * as lc from "vscode-languageclient/node";
+import * as lc from "vscode-languageclient/node";
 import * as ra from "./lsp_ext";
 
 import { Config, prepareVSCodeConfig } from "./config";
@@ -22,6 +22,7 @@ import {
 import { execRevealDependency } from "./commands";
 import { PersistentState } from "./persistent_state";
 import { bootstrap } from "./bootstrap";
+import type { RustAnalyzerExtensionApi } from "./main";
 
 // We only support local folders, not eg. Live Share (`vlsl:` scheme), so don't activate if
 // only those are in use. We use "Empty" to represent these scenarios
@@ -64,7 +65,7 @@ export type CtxInit = Ctx & {
     readonly client: lc.LanguageClient;
 };
 
-export class Ctx {
+export class Ctx implements RustAnalyzerExtensionApi {
     readonly statusBar: vscode.StatusBarItem;
     config: Config;
     readonly workspace: Workspace;
@@ -189,8 +190,11 @@ export class Ctx {
             if (this.config.discoverProjectRunner) {
                 const command = `${this.config.discoverProjectRunner}.discoverWorkspaceCommand`;
                 log.info(`running command: ${command}`);
-                const project: JsonProject = await vscode.commands.executeCommand(command);
-                this.addToDiscoveredWorkspaces([project]);
+                const uris = vscode.workspace.textDocuments
+                    .filter(isRustDocument)
+                    .map((document) => document.uri);
+                const projects: JsonProject[] = await vscode.commands.executeCommand(command, uris);
+                this.setWorkspaces(projects);
             }
 
             if (this.workspace.kind === "Detached Files") {
@@ -342,15 +346,17 @@ export class Ctx {
         return this._serverPath;
     }
 
-    addToDiscoveredWorkspaces(workspaces: JsonProject[]) {
-        for (const workspace of workspaces) {
-            const index = this.config.discoveredWorkspaces.indexOf(workspace);
-            if (~index) {
-                this.config.discoveredWorkspaces[index] = workspace;
-            } else {
-                this.config.discoveredWorkspaces.push(workspace);
-            }
+    setWorkspaces(workspaces: JsonProject[]) {
+        this.config.discoveredWorkspaces = workspaces;
     }
+
+    async notifyRustAnalyzer(): Promise<void> {
+        // this is a workaround to avoid needing writing the `rust-project.json` into
+        // a workspace-level VS Code-specific settings folder. We'd like to keep the
+        // `rust-project.json` entirely in-memory.
+        await this.client?.sendNotification(lc.DidChangeConfigurationNotification.type, {
+            settings: "",
+        });
     }
 
     private updateCommands(forceDisable?: "disable") {

editors/code/src/main.ts

@@ -9,8 +9,12 @@ import { setContextValue } from "./util";
 
 const RUST_PROJECT_CONTEXT_NAME = "inRustProject";
 
+// This API is not stable and may break in between minor releases.
 export interface RustAnalyzerExtensionApi {
     readonly client?: lc.LanguageClient;
+
+    setWorkspaces(workspaces: JsonProject[]): void;
+    notifyRustAnalyzer(): Promise<void>;
 }
 
 export async function deactivate() {
@@ -152,7 +156,6 @@ function createCommands(): Record<string, CommandFactory> {
         shuffleCrateGraph: { enabled: commands.shuffleCrateGraph },
         reloadWorkspace: { enabled: commands.reloadWorkspace },
         rebuildProcMacros: { enabled: commands.rebuildProcMacros },
-        addProject: { enabled: commands.addProject },
         matchingBrace: { enabled: commands.matchingBrace },
         joinLines: { enabled: commands.joinLines },
         parentModule: { enabled: commands.parentModule },