Query hot reloading during development (#1803)

- Depends on #1802

## Checklist

- [ ] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [ ] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [ ] I have not broken the cheatsheet

Author: pokey

packages/cursorless-engine/src/ScopeVisualizer/ScopeRangeWatcher.ts

@@ -1,12 +1,14 @@
-import { Disposable } from "@cursorless/common";
+import { Disposable, showError } from "@cursorless/common";
 import { pull } from "lodash";
 import {
   IterationScopeChangeEventCallback,
   IterationScopeRangeConfig,
   ScopeChangeEventCallback,
   ScopeRangeConfig,
+  ScopeRanges,
 } from "..";
 import { Debouncer } from "../core/Debouncer";
+import { LanguageDefinitions } from "../languages/LanguageDefinitions";
 import { ide } from "../singletons/ide.singleton";
 import { ScopeRangeProvider } from "./ScopeRangeProvider";
 
@@ -19,7 +21,10 @@ export class ScopeRangeWatcher {
   private debouncer = new Debouncer(() => this.onChange());
   private listeners: (() => void)[] = [];
 
-  constructor(private scopeRangeProvider: ScopeRangeProvider) {
+  constructor(
+    languageDefinitions: LanguageDefinitions,
+    private scopeRangeProvider: ScopeRangeProvider,
+  ) {
     this.disposables.push(
       // An Event which fires when the array of visible editors has changed.
       ide().onDidChangeVisibleTextEditors(this.debouncer.run),
@@ -32,6 +37,7 @@ export class ScopeRangeWatcher {
       // dirty-state changes.
       ide().onDidChangeTextDocument(this.debouncer.run),
       ide().onDidChangeTextEditorVisibleRanges(this.debouncer.run),
+      languageDefinitions.onDidChangeDefinition(this.debouncer.run),
       this.debouncer,
     );
 
@@ -54,10 +60,31 @@ export class ScopeRangeWatcher {
   ): Disposable {
     const fn = () => {
       ide().visibleTextEditors.forEach((editor) => {
-        callback(
-          editor,
-          this.scopeRangeProvider.provideScopeRanges(editor, config),
-        );
+        let scopeRanges: ScopeRanges[];
+        try {
+          scopeRanges = this.scopeRangeProvider.provideScopeRanges(
+            editor,
+            config,
+          );
+        } catch (err) {
+          showError(
+            ide().messages,
+            "ScopeRangeWatcher.provide",
+            (err as Error).message,
+          );
+          // If there was a problem getting scopes for an editor, we show an
+          // error and clear any scopes we might have shown last time. This is
+          // especially important during development, but also seems like the
+          // robust thing to do generally.
+          scopeRanges = [];
+
+          if (ide().runMode === "test") {
+            // Fail hard if we're in test mode; otherwise recover
+            throw err;
+          }
+        }
+
+        callback(editor, scopeRanges);
       });
     };
 

packages/cursorless-engine/src/cursorlessEngine.ts

@@ -35,7 +35,6 @@ export function createCursorlessEngine(
   const debug = new Debug(treeSitter);
 
   const rangeUpdater = new RangeUpdater();
-  ide.disposeOnExit(rangeUpdater);
 
   const snippets = new Snippets();
   snippets.init();
@@ -52,7 +51,9 @@ export function createCursorlessEngine(
 
   const testCaseRecorder = new TestCaseRecorder(hatTokenMap, storedTargets);
 
-  const languageDefinitions = new LanguageDefinitions(treeSitter);
+  const languageDefinitions = new LanguageDefinitions(fileSystem, treeSitter);
+
+  ide.disposeOnExit(rangeUpdater, languageDefinitions, hatTokenMap, debug);
 
   return {
     commandApi: {
@@ -108,7 +109,10 @@ function createScopeProvider(
     ),
   );
 
-  const rangeWatcher = new ScopeRangeWatcher(rangeProvider);
+  const rangeWatcher = new ScopeRangeWatcher(
+    languageDefinitions,
+    rangeProvider,
+  );
   const supportChecker = new ScopeSupportChecker(scopeHandlerFactory);
 
   return {

packages/cursorless-engine/src/languages/LanguageDefinition.ts

@@ -35,13 +35,10 @@ export class LanguageDefinition {
    */
   static create(
     treeSitter: TreeSitter,
+    queryDir: string,
     languageId: string,
   ): LanguageDefinition | undefined {
-    const languageQueryPath = join(
-      ide().assetsRoot,
-      "queries",
-      `${languageId}.scm`,
-    );
+    const languageQueryPath = join(queryDir, `${languageId}.scm`);
 
     if (!existsSync(languageQueryPath)) {
       return undefined;

packages/cursorless-engine/src/languages/LanguageDefinitions.ts

@@ -1,6 +1,15 @@
-import { Range, TextDocument } from "@cursorless/common";
+import {
+  Disposable,
+  FileSystem,
+  Notifier,
+  Range,
+  TextDocument,
+  getCursorlessRepoRoot,
+} from "@cursorless/common";
+import { join } from "path";
 import { SyntaxNode } from "web-tree-sitter";
 import { TreeSitter } from "..";
+import { ide } from "../singletons/ide.singleton";
 import { LanguageDefinition } from "./LanguageDefinition";
 
 /**
@@ -14,6 +23,8 @@ const LANGUAGE_UNDEFINED = Symbol("LANGUAGE_UNDEFINED");
  * constructing them as necessary
  */
 export class LanguageDefinitions {
+  private notifier: Notifier = new Notifier();
+
   /**
    * Maps from language id to {@link LanguageDefinition} or
    * {@link LANGUAGE_UNDEFINED} if language doesn't have new-style definitions.
@@ -28,8 +39,31 @@ export class LanguageDefinitions {
     string,
     LanguageDefinition | typeof LANGUAGE_UNDEFINED
   > = new Map();
+  private queryDir: string;
+  private disposables: Disposable[] = [];
+
+  constructor(
+    fileSystem: FileSystem,
+    private treeSitter: TreeSitter,
+  ) {
+    // Use the repo root as the root for development mode, so that we can
+    // we can make hot-reloading work for the queries
+    this.queryDir = join(
+      ide().runMode === "development"
+        ? getCursorlessRepoRoot()
+        : ide().assetsRoot,
+      "queries",
+    );
 
-  constructor(private treeSitter: TreeSitter) {}
+    if (ide().runMode === "development") {
+      this.disposables.push(
+        fileSystem.watchDir(this.queryDir, () => {
+          this.languageDefinitions.clear();
+          this.notifier.notifyListeners();
+        }),
+      );
+    }
+  }
 
   /**
    * Get a language definition for the given language id, if the language
@@ -44,7 +78,7 @@ export class LanguageDefinitions {
 
     if (definition == null) {
       definition =
-        LanguageDefinition.create(this.treeSitter, languageId) ??
+        LanguageDefinition.create(this.treeSitter, this.queryDir, languageId) ??
         LANGUAGE_UNDEFINED;
 
       this.languageDefinitions.set(languageId, definition);
@@ -59,4 +93,10 @@ export class LanguageDefinitions {
   public getNodeAtLocation(document: TextDocument, range: Range): SyntaxNode {
     return this.treeSitter.getNodeAtLocation(document, range);
   }
+
+  onDidChangeDefinition = this.notifier.registerListener;
+
+  dispose() {
+    this.disposables.forEach((disposable) => disposable.dispose());
+  }
 }

packages/cursorless-engine/src/processTargets/modifiers/scopeHandlers/TreeSitterScopeHandler/BaseTreeSitterScopeHandler.ts

@@ -3,6 +3,7 @@ import {
   Position,
   TextDocument,
   TextEditor,
+  showError,
 } from "@cursorless/common";
 import { uniqWith } from "lodash";
 import { TreeSitterQuery } from "../../../../languages/TreeSitterQuery";
@@ -15,6 +16,7 @@ import {
   ScopeIteratorRequirements,
 } from "../scopeHandler.types";
 import { mergeAdjacentBy } from "./mergeAdjacentBy";
+import { ide } from "../../../../singletons/ide.singleton";
 
 /** Base scope handler to use for both tree-sitter scopes and their iteration scopes */
 export abstract class BaseTreeSitterScopeHandler extends BaseScopeHandler {
@@ -65,9 +67,18 @@ export abstract class BaseTreeSitterScopeHandler extends BaseScopeHandler {
               targets.length > 1 &&
               !equivalentScopes.every((scope) => scope.allowMultiple)
             ) {
-              throw Error(
-                "Please use #allow-multiple! predicate in your query to allow multiple matches for this scope type",
+              const message =
+                "Please use #allow-multiple! predicate in your query to allow multiple matches for this scope type";
+
+              showError(
+                ide().messages,
+                "BaseTreeSitterScopeHandler.allow-multiple",
+                message,
               );
+
+              if (ide().runMode === "test") {
+                throw Error(message);
+              }
             }
 
             return targets;