Multi-root workspace support and Fix TextMate grammar bugs

.github/copilot-instructions.md

@@ -0,0 +1,74 @@
+# Copilot Instructions
+
+## Build, Test, and Lint
+
+This is a multi-package monorepo (root, `client/`, `server/`, `scripts/`). Each has its own `node_modules` and `package.json`. The root `npm install` runs `npm install-clean` in all sub-packages via `postinstall`.
+
+```shell
+npm install          # install all packages (root + client + server + scripts)
+npm run build        # TypeScript compile all packages
+npm run lint         # ESLint all packages
+
+# Server unit tests (mocha, no build dependency)
+npm run test:server
+
+# Client UI tests (vscode-test-electron, requires webpack first)
+npm run webpack-prod
+npm run test:client
+
+# Run a single server test file directly
+cd server
+npx mocha --require ts-node/register src/test/<file>.test.ts
+
+# Package the extension
+npm run vsix
+```
+
+## Architecture
+
+This is a VS Code extension providing Language Server Protocol (LSP) support for the Power Query / M formula language.
+
+**Client** (`client/src/extension.ts`): Activates the extension, starts the language server over **Node IPC**, and manages the library symbol system. Exposes a `PowerQueryApi` for other extensions.
+
+**Server** (`server/src/server.ts`): Handles LSP requests — completion, hover, definition, formatting, diagnostics, rename, folding, document symbols, semantic tokens, and signature help. Request handling follows a consistent pattern: fetch document → create cancellation token → build a `PQLS.Analysis` → call the analysis API → map results to LSP types. Errors go through `ErrorUtils.handleError`.
+
+**Scripts** (`scripts/`): Standalone benchmark/tooling utilities, not part of the extension runtime.
+
+**Core dependencies** (Microsoft-owned, all three are used across the codebase):
+
+- `@microsoft/powerquery-parser` — Lexer, parser, and type validation
+- `@microsoft/powerquery-language-services` — Higher-level language service (Analysis, completions, hover, etc.)
+- `@microsoft/powerquery-formatter` — Code formatter (server-side only)
+
+### Library Symbol System
+
+External library symbols allow users to extend the M standard library with custom function definitions loaded from JSON files on disk. The flow:
+
+1. User configures `powerquery.client.additionalSymbolsDirectories` setting
+2. `LibrarySymbolManager` scans directories for `.json` files, parses them via `LibrarySymbolUtils`
+3. `LibrarySymbolClient` sends symbols to the server via custom LSP requests (`powerquery/addLibrarySymbols`, `powerquery/removeLibrarySymbols`)
+4. Server merges external symbols with built-in standard/SDK library in `SettingsUtils.getLibrary()`
+
+### Local Development with Sibling Packages
+
+Use `npm run link:start` to develop against locally-built copies of the parser, formatter, and language-services packages (via `npm link`). Use `npm run link:stop` to revert to published npm versions.
+
+## Code Conventions
+
+**TypeScript strictness** — The ESLint config enforces rules that are stricter than typical TypeScript projects:
+
+- `explicit-function-return-type`: All functions must have explicit return type annotations
+- `typedef`: Required on variables, parameters, properties, arrow parameters, and destructuring
+- `no-floating-promises`: All promises must be awaited or handled
+- `switch-exhaustiveness-check`: Switch statements must cover all cases
+- `sort-imports`: Imports must be sorted (separated groups allowed, case-insensitive)
+- `no-plusplus`: Use `+= 1` instead of `++`
+- `object-shorthand`: Always use shorthand properties/methods
+- `arrow-body-style`: Use concise arrow function bodies (no braces for single expressions)
+- `curly`: Always use braces for control flow, even single-line
+
+**Formatting** (Prettier): 120 char line width, 4-space indent, trailing commas, no parens on single arrow params.
+
+**Import aliases**: The codebase uses `PQP` for powerquery-parser, `PQLS` for powerquery-language-services, and `PQF` for powerquery-formatter.
+
+**Testing**: Server tests use Mocha (`describe`/`it`) with Chai `expect` and Node `assert`. Client tests use VS Code's test runner (`suite`/`test` TDD-style).

client/.vscode-test.js

@@ -7,7 +7,7 @@ const { defineConfig } = require('@vscode/test-cli');
 module.exports = defineConfig([
   {
     label: "UI Tests",
-    files: "lib/test/**/*.test.js",
+    files: "lib/test/**/!(multiRootWorkspace).test.js",
     workspaceFolder: "src/test/testFixture",
     extensionDevelopmentPath: "..",
     launchArgs: ["--profile-temp", "--disable-extensions"],
@@ -26,5 +26,19 @@ module.exports = defineConfig([
       //   },
       // }
     }
+  },
+  {
+    label: "Multi-root Workspace Tests",
+    files: "lib/test/**/multiRootWorkspace.test.js",
+    workspaceFolder: "src/test/multiRootFixture/test.code-workspace",
+    extensionDevelopmentPath: "..",
+    launchArgs: ["--profile-temp", "--disable-extensions"],
+
+    mocha: {
+      color: true,
+      ui: "tdd",
+      timeout: 20000,
+      slow: 10000,
+    }
   }
 ]);

client/src/extension.ts

@@ -63,7 +63,7 @@ export async function activate(context: vscode.ExtensionContext): Promise<PowerQ
     librarySymbolClient = new LibrarySymbolClient(client);
     librarySymbolManager = new LibrarySymbolManager(librarySymbolClient, client);
 
-    await configureSymbolDirectories();
+    await configureAllFolderSymbolDirectories();
 
     context.subscriptions.push(
         vscode.workspace.onDidChangeConfiguration(async (event: vscode.ConfigurationChangeEvent) => {
@@ -73,9 +73,20 @@ export async function activate(context: vscode.ExtensionContext): Promise<PowerQ
             );
 
             if (event.affectsConfiguration(symbolDirs)) {
-                await configureSymbolDirectories();
+                await configureAllFolderSymbolDirectories();
             }
         }),
+        vscode.workspace.onDidChangeWorkspaceFolders(async (event: vscode.WorkspaceFoldersChangeEvent) => {
+            await Promise.all(
+                event.removed.map((folder: vscode.WorkspaceFolder) =>
+                    librarySymbolManager.removeSymbolsForFolder(folder.uri.toString()),
+                ),
+            );
+
+            await Promise.all(
+                event.added.map((folder: vscode.WorkspaceFolder) => configureSymbolDirectoriesForFolder(folder)),
+            );
+        }),
     );
 
     return Object.freeze(librarySymbolClient);
@@ -85,18 +96,37 @@ export function deactivate(): Thenable<void> | undefined {
     return client?.stop();
 }
 
-async function configureSymbolDirectories(): Promise<void> {
-    const config: vscode.WorkspaceConfiguration = vscode.workspace.getConfiguration(ConfigurationConstant.BasePath);
+async function configureAllFolderSymbolDirectories(): Promise<void> {
+    const folders: readonly vscode.WorkspaceFolder[] | undefined = vscode.workspace.workspaceFolders;
+
+    if (!folders || folders.length === 0) {
+        // No workspace folders — read global config
+        const config: vscode.WorkspaceConfiguration = vscode.workspace.getConfiguration(ConfigurationConstant.BasePath);
+
+        const additionalSymbolsDirectories: string[] | undefined = config.get(
+            ConfigurationConstant.AdditionalSymbolsDirectories,
+        );
+
+        await librarySymbolManager.refreshSymbolDirectories(additionalSymbolsDirectories ?? []);
+
+        return;
+    }
+
+    await Promise.all(folders.map((folder: vscode.WorkspaceFolder) => configureSymbolDirectoriesForFolder(folder)));
+}
+
+async function configureSymbolDirectoriesForFolder(folder: vscode.WorkspaceFolder): Promise<void> {
+    const config: vscode.WorkspaceConfiguration = vscode.workspace.getConfiguration(
+        ConfigurationConstant.BasePath,
+        folder.uri,
+    );
 
     const additionalSymbolsDirectories: string[] | undefined = config.get(
         ConfigurationConstant.AdditionalSymbolsDirectories,
     );
 
-    // TODO: Should we fix/remove invalid and malformed directory path values?
-    // For example, a quoted path "c:\path\to\file" will be considered invalid and reported as an error.
-    // We could modify values and write them back to the original config locations.
-
-    await librarySymbolManager.refreshSymbolDirectories(additionalSymbolsDirectories ?? []);
-
-    // TODO: Configure file system watchers to detect library file changes.
+    await librarySymbolManager.refreshSymbolDirectoriesForFolder(
+        folder.uri.toString(),
+        additionalSymbolsDirectories ?? [],
+    );
 }