src: fix error message in async_hooks constructor

There are two minor issues in the AsyncHook constructor, if the object
passed in has an after and/or destroy property that are not functions
the errors thrown will still be:
TypeError [ERR_ASYNC_CALLBACK]: before must be a function

This commit updates the code and adds a unit test.

lib/async_hooks.js

@@ -45,9 +45,9 @@ class AsyncHook {
     if (before !== undefined && typeof before !== 'function')
       throw new errors.TypeError('ERR_ASYNC_CALLBACK', 'before');
     if (after !== undefined && typeof after !== 'function')
-      throw new errors.TypeError('ERR_ASYNC_CALLBACK', 'before');
+      throw new errors.TypeError('ERR_ASYNC_CALLBACK', 'after');
     if (destroy !== undefined && typeof destroy !== 'function')
-      throw new errors.TypeError('ERR_ASYNC_CALLBACK', 'before');
+      throw new errors.TypeError('ERR_ASYNC_CALLBACK', 'destroy');
     if (promiseResolve !== undefined && typeof promiseResolve !== 'function')
       throw new errors.TypeError('ERR_ASYNC_CALLBACK', 'promiseResolve');
 

test/parallel/test-async-hooks-constructor.js

@@ -0,0 +1,35 @@
+'use strict';
+
+// This tests that AsyncHooks throws an error if bad parameters are passed.
+
+const common = require('../common');
+const async_hooks = require('async_hooks');
+const non_function = 10;
+
+common.expectsError(() => {
+  async_hooks.createHook({ init: non_function });
+}, typeErrorForFunction('init'));
+
+common.expectsError(() => {
+  async_hooks.createHook({ before: non_function });
+}, typeErrorForFunction('before'));
+
+common.expectsError(() => {
+  async_hooks.createHook({ after: non_function });
+}, typeErrorForFunction('after'));
+
+common.expectsError(() => {
+  async_hooks.createHook({ destroy: non_function });
+}, typeErrorForFunction('destroy'));
+
+common.expectsError(() => {
+  async_hooks.createHook({ promiseResolve: non_function });
+}, typeErrorForFunction('promiseResolve'));
+
+function typeErrorForFunction(functionName) {
+  return {
+    code: 'ERR_ASYNC_CALLBACK',
+    type: TypeError,
+    message: `${functionName} must be a function`,
+  };
+}