Test: add fixture for rejected "begin", "moduleStart", "done" callbacks

I'm adding this as a CLI fixture instead of an HTML fixture because
we don't currently have a good way of expecting a failure in an HTML
test run. I've confirmed that the "hanging" appearance described in
#1391 is equivalent to the
"Process exited before tests finished running" message reported.

Once we switch to capturing TAP by default, this will make the HTML
tests much easier to verify no matter whether the pass/fail outcome.

Ref #1391.

test/cli/cli-main.js

@@ -38,6 +38,7 @@ const fixtureCases = {
   'uncaught error in "moduleDone" callback"': ['qunit', 'bad-callbacks/moduleDone-throw.js'],
   // FIXME: Details of testStart() error are swallowed
   'uncaught error in "testStart" callback"': ['qunit', 'bad-callbacks/testStart-throw.js'],
+  'rejection from callbacks': ['qunit', 'callbacks-rejected.js'],
 
   'QUnit.hooks context': ['qunit', 'hooks-global-context.js'],
 

test/cli/fixtures/callbacks-rejected.js

@@ -0,0 +1,37 @@
+var caught = [];
+
+QUnit.on('error', function (e) {
+  caught.push(e.message);
+});
+
+QUnit.begin(function () {
+  return Promise.reject(new Error('begin'));
+});
+
+QUnit.moduleStart(function () {
+  return Promise.reject(new Error('moduleStart'));
+});
+
+QUnit.testStart(function () {
+  return Promise.reject(new Error('testStart'));
+});
+
+QUnit.done(function () {
+  setTimeout(function () {
+    console.log('Caught errors from ' + caught.join(', '));
+  }, 100);
+});
+
+QUnit.done(function () {
+  return Promise.reject(new Error('done'));
+});
+
+QUnit.test('one', function (assert) {
+  assert.ok(true);
+});
+
+QUnit.module('example', function () {
+  QUnit.test('two', function (assert) {
+    assert.ok(true);
+  });
+});

test/cli/fixtures/expected/tap-outputs.js

@@ -303,6 +303,25 @@ Error: Process exited before tests finished running
 # stderr
 Error: Process exited before tests finished running
 
+# exit code: 1`,
+
+  'qunit callbacks-rejected.js':
+`TAP version 13
+not ok 1 global failure
+  ---
+  message: Error: begin
+  severity: failed
+  stack: |
+    Error: begin
+        at /qunit/test/cli/fixtures/callbacks-rejected.js:8:25
+        at qunit.js
+        at internal
+  ...
+Bail out! Error: begin
+
+# stderr
+Error: Process exited before tests finished running
+
 # exit code: 1`,
 
   'qunit no-tests':