assert: restore TypeError if no arguments

In Node 7.x, calling `throw new assert.AssertionError()` resulted in a
TypeError.

In current master, the same call does not result in an error but, due to
the default option, it results in uninformative output ("undefined
undefined undefined").

This change removes the default argument, restoring a TypeError if there
is no argument. This also will restore our test coverage to 100%. (The
default argument is not tested in our current test suite.)

PR-URL: #12843
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Joyee Cheung <[email protected]>
Reviewed-By: Refael Ackermann <[email protected]>
Reviewed-By: James M Snell <[email protected]>

lib/assert.js

@@ -47,7 +47,7 @@ const assert = module.exports = ok;
 
 // TODO(jasnell): Consider moving AssertionError into internal/errors.js
 class AssertionError extends Error {
-  constructor(options = {}) {
+  constructor(options) {
     if (typeof options !== 'object' || options === null) {
       // Lazy because the errors module itself uses assertions, leading to
       // a circular dependency. This can be eliminated by moving this class

test/parallel/test-assert.js

@@ -707,12 +707,16 @@ assert.throws(() => {
   code: 'ERR_ASSERTION',
   message: new RegExp(`^'${'A'.repeat(127)} === ''$`)}));
 
-[1, true, false, '', null, Infinity, Symbol('test')].forEach((input) => {
-  assert.throws(
-    () => new assert.AssertionError(input),
-    common.expectsError({
-      code: 'ERR_INVALID_ARG_TYPE',
-      type: TypeError,
-      message: /^The "options" argument must be of type object$/
-    }));
-});
+{
+  // bad args to AssertionError constructor should throw TypeError
+  const args = [1, true, false, '', null, Infinity, Symbol('test'), undefined];
+  args.forEach((input) => {
+    assert.throws(
+      () => new assert.AssertionError(input),
+      common.expectsError({
+        code: 'ERR_INVALID_ARG_TYPE',
+        type: TypeError,
+        message: /^The "options" argument must be of type object$/
+      }));
+  });
+}