Throw error instead of using fail method

extensions/ql-vscode/test/unit-tests/command-lint.test.ts

@@ -49,7 +49,7 @@ describe("commands declared in package.json", () => {
       expect(title).toBeDefined();
       commandTitles[command] = title!;
     } else {
-      fail(`Unexpected command name ${command}`);
+      throw new Error(`Unexpected command name ${command}`);
     }
   });
 

extensions/ql-vscode/test/unit-tests/pure/helpers-pure.test.ts

@@ -13,7 +13,7 @@ describe("helpers-pure", () => {
 
     try {
       await asyncFilter([1, 2, 3], rejects);
-      fail("Should have thrown");
+      throw new Error("Should have thrown");
     } catch (e) {
       expect(getErrorMessage(e)).toBe("opps");
     }

extensions/ql-vscode/test/vscode-tests/cli-integration/debugger/debug-controller.ts

@@ -310,11 +310,7 @@ export class DebugController
    */
   private async nextEvent(): Promise<AnyDebugEvent> {
     if (this.resolver !== undefined) {
-      const error = new Error(
-        "Attempt to wait for multiple debugger events at once.",
-      );
-      fail(error);
-      throw error;
+      throw new Error("Attempt to wait for multiple debugger events at once.");
     } else {
       if (this.nextEventIndex < this.eventQueue.length) {
         // No need to wait.