assert: add rejects() and doesNotReject()

Implement asynchronous equivalent for assert.throws() and
assert.doesNotThrow().

PR-URL: https://github.com/nodejs/node/pull/18023
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Shingo Inoue <leko.noor@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

test/parallel/test-assert-async.js

@@ -0,0 +1,66 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const { promisify } = require('util');
+const wait = promisify(setTimeout);
+
+/* eslint-disable prefer-common-expectserror, no-restricted-properties */
+
+// Test assert.rejects() and assert.doesNotReject() by checking their
+// expected output and by verifying that they do not work sync
+
+assert.rejects(
+  () => assert.fail(),
+  common.expectsError({
+    code: 'ERR_ASSERTION',
+    type: assert.AssertionError,
+    message: 'Failed'
+  })
+);
+
+assert.doesNotReject(() => {});
+
+{
+  const promise = assert.rejects(async () => {
+    await wait(1);
+    assert.fail();
+  }, common.expectsError({
+    code: 'ERR_ASSERTION',
+    type: assert.AssertionError,
+    message: 'Failed'
+  }));
+  assert.doesNotReject(() => promise);
+}
+
+{
+  const promise = assert.doesNotReject(async () => {
+    await wait(1);
+    throw new Error();
+  });
+  assert.rejects(() => promise,
+                 (err) => {
+                   assert(err instanceof assert.AssertionError,
+                          `${err.name} is not instance of AssertionError`);
+                   assert.strictEqual(err.code, 'ERR_ASSERTION');
+                   assert(/^Got unwanted rejection\.\n$/.test(err.message));
+                   assert.strictEqual(err.operator, 'doesNotReject');
+                   assert.ok(!err.stack.includes('at Function.doesNotReject'));
+                   return true;
+                 }
+  );
+}
+
+{
+  const promise = assert.rejects(() => {});
+  assert.rejects(() => promise,
+                 (err) => {
+                   assert(err instanceof assert.AssertionError,
+                          `${err.name} is not instance of AssertionError`);
+                   assert.strictEqual(err.code, 'ERR_ASSERTION');
+                   assert(/^Missing expected rejection\.$/.test(err.message));
+                   assert.strictEqual(err.operator, 'rejects');
+                   assert.ok(!err.stack.includes('at Function.rejects'));
+                   return true;
+                 }
+  );
+}