Make language loading more robust (#2350)

## 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/languages/LanguageDefinitions.ts

@@ -5,12 +5,15 @@ import {
   Range,
   TextDocument,
   getCursorlessRepoRoot,
+  isTesting,
+  showError,
 } from "@cursorless/common";
 import { join } from "path";
 import { SyntaxNode } from "web-tree-sitter";
 import { TreeSitter } from "../typings/TreeSitter";
 import { ide } from "../singletons/ide.singleton";
 import { LanguageDefinition } from "./LanguageDefinition";
+import { toString } from "lodash";
 
 /**
  * Sentinel value to indicate that a language doesn't have
@@ -78,9 +81,20 @@ export class LanguageDefinitions {
       ({ document }) => document.languageId,
     );
 
-    await Promise.all(
-      languageIds.map((languageId) => this.loadLanguage(languageId)),
-    );
+    try {
+      await Promise.all(
+        languageIds.map((languageId) => this.loadLanguage(languageId)),
+      );
+    } catch (err) {
+      showError(
+        ide().messages,
+        "Failed to load language definitions",
+        toString(err),
+      );
+      if (isTesting()) {
+        throw err;
+      }
+    }
   }
 
   public async loadLanguage(languageId: string): Promise<void> {
@@ -100,11 +114,8 @@ export class LanguageDefinitions {
   }
 
   private async reloadLanguageDefinitions(): Promise<void> {
-    const languageIds = Array.from(this.languageDefinitions.keys());
     this.languageDefinitions.clear();
-    await Promise.all(
-      languageIds.map((languageId) => this.loadLanguage(languageId)),
-    );
+    await this.loadAllLanguages();
     this.notifier.notifyListeners();
   }