test_runner: handle errors not bound to tests

This commit addresses a previously untested branch of the code.
It is possible when using the test runner that an error occurs
outside of a test. In this case, the test runner would simply
rethrow the error. This commit updates the logic to handle the
error in the same fashion as other uncaughtExceptions.

PR-URL: #46962
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>

lib/internal/test_runner/harness.js

@@ -39,17 +39,21 @@ function createProcessEventHandler(eventName, rootTest) {
     // Check if this error is coming from a test. If it is, fail the test.
     const test = testResources.get(executionAsyncId());
 
-    if (!test) {
-      throw err;
-    }
-
-    if (test.finished) {
-      // If the test is already finished, report this as a top level
-      // diagnostic since this is a malformed test.
-      const msg = `Warning: Test "${test.name}" generated asynchronous ` +
-        'activity after the test ended. This activity created the error ' +
-        `"${err}" and would have caused the test to fail, but instead ` +
-        `triggered an ${eventName} event.`;
+    if (!test || test.finished) {
+      // If the test is already finished or the resource that created the error
+      // is not mapped to a Test, report this as a top level diagnostic.
+      let msg;
+
+      if (test) {
+        msg = `Warning: Test "${test.name}" generated asynchronous ` +
+          'activity after the test ended. This activity created the error ' +
+          `"${err}" and would have caused the test to fail, but instead ` +
+          `triggered an ${eventName} event.`;
+      } else {
+        msg = 'Warning: A resource generated asynchronous activity after ' +
+          `the test ended. This activity created the error "${err}" which ` +
+          `triggered an ${eventName} event, caught by the test runner.`;
+      }
 
       rootTest.diagnostic(msg);
       process.exitCode = 1;

test/message/test_runner_output.js

@@ -383,3 +383,9 @@ test('unfinished test with unhandledRejection', async () => {
     setTimeout(() => Promise.reject(new Error('bar')));
   });
 });
+
+// Verify that uncaught exceptions outside of any tests are handled after the
+// test harness has finished bootstrapping itself.
+setImmediate(() => {
+  throw new Error('uncaught from outside of a test');
+});

test/message/test_runner_output.out

@@ -637,6 +637,7 @@ not ok 65 - invalid subtest fail
 1..65
 # Warning: Test "unhandled rejection - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: rejected from unhandled rejection fail" and would have caused the test to fail, but instead triggered an unhandledRejection event.
 # Warning: Test "async unhandled rejection - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: rejected from async unhandled rejection fail" and would have caused the test to fail, but instead triggered an unhandledRejection event.
+# Warning: A resource generated asynchronous activity after the test ended. This activity created the error "Error: uncaught from outside of a test" which triggered an uncaughtException event, caught by the test runner.
 # Warning: Test "immediate throw - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: thrown from immediate throw fail" and would have caused the test to fail, but instead triggered an uncaughtException event.
 # Warning: Test "immediate reject - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: rejected from immediate reject fail" and would have caused the test to fail, but instead triggered an unhandledRejection event.
 # Warning: Test "callback called twice in different ticks" generated asynchronous activity after the test ended. This activity created the error "Error [ERR_TEST_FAILURE]: callback invoked multiple times" and would have caused the test to fail, but instead triggered an uncaughtException event.

test/message/test_runner_output_cli.out

@@ -636,6 +636,7 @@ not ok 65 - invalid subtest fail
   ...
 # Warning: Test "unhandled rejection - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: rejected from unhandled rejection fail" and would have caused the test to fail, but instead triggered an unhandledRejection event.
 # Warning: Test "async unhandled rejection - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: rejected from async unhandled rejection fail" and would have caused the test to fail, but instead triggered an unhandledRejection event.
+# Warning: A resource generated asynchronous activity after the test ended. This activity created the error "Error: uncaught from outside of a test" which triggered an uncaughtException event, caught by the test runner.
 # Warning: Test "immediate throw - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: thrown from immediate throw fail" and would have caused the test to fail, but instead triggered an uncaughtException event.
 # Warning: Test "immediate reject - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: rejected from immediate reject fail" and would have caused the test to fail, but instead triggered an unhandledRejection event.
 # Warning: Test "callback called twice in different ticks" generated asynchronous activity after the test ended. This activity created the error "Error [ERR_TEST_FAILURE]: callback invoked multiple times" and would have caused the test to fail, but instead triggered an uncaughtException event.

test/message/test_runner_output_spec_reporter.out

@@ -270,6 +270,7 @@
 
  Warning: Test "unhandled rejection - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: rejected from unhandled rejection fail" and would have caused the test to fail, but instead triggered an unhandledRejection event.
  Warning: Test "async unhandled rejection - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: rejected from async unhandled rejection fail" and would have caused the test to fail, but instead triggered an unhandledRejection event.
+ Warning: A resource generated asynchronous activity after the test ended. This activity created the error "Error: uncaught from outside of a test" which triggered an uncaughtException event, caught by the test runner.
  Warning: Test "immediate throw - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: thrown from immediate throw fail" and would have caused the test to fail, but instead triggered an uncaughtException event.
  Warning: Test "immediate reject - passes but warns" generated asynchronous activity after the test ended. This activity created the error "Error: rejected from immediate reject fail" and would have caused the test to fail, but instead triggered an unhandledRejection event.
  Warning: Test "callback called twice in different ticks" generated asynchronous activity after the test ended. This activity created the error "Error [ERR_TEST_FAILURE]: callback invoked multiple times" and would have caused the test to fail, but instead triggered an uncaughtException event.