nodejs · jasnell · Feb 10, 2017 · joyeecheung · Feb 11, 2017 · joyeecheung
diff --git a/doc/api/errors.md b/doc/api/errors.md
@@ -36,8 +36,8 @@ called.
 
 All JavaScript errors are handled as exceptions that *immediately* generate
 and throw an error using the standard JavaScript `throw` mechanism. These
-are handled using the [`try / catch` construct][try-catch] provided by the JavaScript
-language.
+are handled using the [`try / catch` construct][try-catch] provided by the
+JavaScript language.
 
 ```js
 // Throws with a ReferenceError because z is undefined
@@ -105,8 +105,8 @@ pass or fail).
 
 For *all* `EventEmitter` objects, if an `'error'` event handler is not
 provided, the error will be thrown, causing the Node.js process to report an
-unhandled exception and  crash unless either: The [`domain`][domains] module is used
-appropriately or a handler has been registered for the
+unhandled exception and  crash unless either: The [`domain`][domains] module is
+used appropriately or a handler has been registered for the
 [`process.on('uncaughtException')`][] event.
 
 ```js
@@ -255,15 +255,23 @@ will affect any stack trace captured *after* the value has been changed.
 If set to a non-number value, or set to a negative number, stack traces will
 not capture any frames.
 
-### error.message
+#### error.code
+
+* {string}
+
+The `error.code` property is a string label that identifies the kind of error.
+See [Node.js Error Codes][] for details about specific codes.
+
+#### error.message
 
 * {string}
 
-The `error.message` property is the string description of the error as set by calling `new Error(message)`.
-The `message` passed to the constructor will also appear in the first line of
-the stack trace of the `Error`, however changing this property after the
-`Error` object is created *may not* change the first line of the stack trace
-(for example, when `error.stack` is read before this property is changed).
+The `error.message` property is the string description of the error as set by
+calling `new Error(message)`. The `message` passed to the constructor will also
+appear in the first line of the stack trace of the `Error`, however changing
+this property after the `Error` object is created *may not* change the first
+line of the stack trace (for example, when `error.stack` is read before this
+property is changed).
 
 ```js
 const err = new Error('The message');
@@ -451,18 +459,18 @@ added properties.
 
 * {string}
 
-The `error.code` property is a string representing the error code, which is always
-`E` followed by a sequence of capital letters.
+The `error.code` property is a string representing the error code, which is
+typically `E` followed by a sequence of capital letters.
 
 #### error.errno
 
 * {string|number}
 
 The `error.errno` property is a number or a string.
-The number is a **negative** value which corresponds to the error code defined in
-[`libuv Error handling`]. See uv-errno.h header file (`deps/uv/include/uv-errno.h` in
-the Node.js source tree) for details.
-In case of a string, it is the same as `error.code`.
+The number is a **negative** value which corresponds to the error code defined
+in [`libuv Error handling`]. See uv-errno.h header file
+(`deps/uv/include/uv-errno.h` in the Node.js source tree) for details. In case
+of a string, it is the same as `error.code`.
 
 #### error.syscall
 
@@ -474,22 +482,22 @@ The `error.syscall` property is a string describing the [syscall][] that failed.
 
 * {string}
 
-When present (e.g. in `fs` or `child_process`), the `error.path` property is a string
-containing a relevant invalid pathname.
+When present (e.g. in `fs` or `child_process`), the `error.path` property is a
+string containing a relevant invalid pathname.
 
 #### error.address
 
 * {string}
 
-When present (e.g. in `net` or `dgram`), the `error.address` property is a string
-describing the address to which the connection failed.
+When present (e.g. in `net` or `dgram`), the `error.address` property is a
+string describing the address to which the connection failed.
 
 #### error.port
 
 * {number}
 
-When present (e.g. in `net` or `dgram`), the `error.port` property is a number representing
-the connection's port that is not available.
+When present (e.g. in `net` or `dgram`), the `error.port` property is a number
+representing the connection's port that is not available.
 
 ### Common System Errors
 
@@ -550,6 +558,53 @@ found [here][online].
   encountered by [`http`][] or [`net`][] -- often a sign that a `socket.end()`
   was not properly called.
 
+<a id="nodejs-error-codes"></a>
+## Node.js Error Codes
+
+<a id="ERR_INVALID_ARG_TYPE"></a>
+### ERR_INVALID_ARG_TYPE
+
+The `'ERR_INVALID_ARG_TYPE'` error code is used generically to identify that
+an argument of the wrong type has been passed to a Node.js API.
+
+<a id="ERR_INVALID_CALLBACK"></a>
+### ERR_INVALID_CALLBACK
+
+The `'ERR_INVALID_CALLBACK'` error code is used generically to identify that
+a callback function is required and has not been provided to a Node.js API.
+
+<a id="ERR_STDERR_CLOSE"></a>
+### ERR_STDERR_CLOSE
+
+An error using the `'ERR_STDERR_CLOSE'` code is thrown specifically when an
+attempt is made to close the `process.stderr` stream. By design, Node.js does
+not allow `stdout` or `stderr` Streams to be closed by user code.
+
+<a id="ERR_STDOUT_CLOSE"></a>
+### ERR_STDOUT_CLOSE
+
+An error using the `'ERR_STDOUT_CLOSE'` code is thrown specifically when an
+attempt is made to close the `process.stdout` stream. By design, Node.js does
+not allow `stdout` or `stderr` Streams to be closed by user code.
+
+<a id="ERR_UNKNOWN_STDIN_TYPE"></a>
+### ERR_UNKNOWN_STDIN_TYPE
+
+An error using the `'ERR_UNKNOWN_STDIN_TYPE'` code is thrown specifically when
+an attempt is made to launch a Node.js process with an unknown `stdin` file
+type. Errors of this kind cannot *typically* be caused by errors in user code,
+although it is not impossible. Occurrences of this error are most likely an
+indication of a bug within Node.js itself.
+
+<a id="ERR_UNKNOWN_STREAM_TYPE"></a>
+### ERR_UNKNOWN_STREAM_TYPE
+
+An error using the `'ERR_UNKNOWN_STREAM_TYPE'` code is thrown specifically when
+an attempt is made to launch a Node.js process with an unknown `stdout` or
+`stderr` file type. Errors of this kind cannot *typically* be caused by errors
+in user code, although it is not impossible. Occurrences of this error are most
+likely an indication of a bug within Node.js itself.
+
 [`fs.readdir`]: fs.html#fs_fs_readdir_path_options_callback
 [`fs.readFileSync`]: fs.html#fs_fs_readfilesync_file_options
 [`fs.unlink`]: fs.html#fs_fs_unlink_path_callback
@@ -562,6 +617,7 @@ found [here][online].
 [domains]: domain.html
 [event emitter-based]: events.html#events_class_eventemitter
 [file descriptors]: https://en.wikipedia.org/wiki/File_descriptor
+[Node.js Error Codes]: #nodejs-error-codes
 [online]: http://man7.org/linux/man-pages/man3/errno.3.html
 [stream-based]: stream.html
 [syscall]: http://man7.org/linux/man-pages/man2/syscall.2.html

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
@@ -80,4 +80,32 @@ module.exports = exports = {
 //
 // Note: Please try to keep these in alphabetical order
 E('ERR_ASSERTION', (msg) => msg);
+E('ERR_INVALID_ARG_TYPE', invalidArgType);
+E('ERR_INVALID_CALLBACK', 'callback must be a function');
+E('ERR_STDERR_CLOSE', 'process.stderr cannot be closed');
+E('ERR_STDOUT_CLOSE', 'process.stdout cannot be closed');
+E('ERR_UNKNOWN_STDIN_TYPE', 'Unknown stdin file type');
+E('ERR_UNKNOWN_STREAM_TYPE', 'Unknown stream file type');
 // Add new errors from here...
+
+function invalidArgType(name, expected, actual) {
+  assert(name, 'name is required');
+  assert(expected, 'expected is required');
+  var msg = `The "${name}" argument must be `;
+  if (Array.isArray(expected)) {
+    var len = expected.length;
+    expected = expected.map((i) => String(i));
+    if (len > 1) {
+      msg += `one of type ${expected.slice(0, len - 1).join(', ')}, or ` +
+             expected[len - 1];
+    } else {
+      msg += `of type ${expected[0]}`;
+    }
+  } else {
+    msg += `of type ${String(expected)}`;
+  }
+  if (arguments.length >= 3) {
+    msg += `. Received type ${actual !== null ? typeof actual : 'null'}`;
+  }
+  return msg;
+}
diff --git a/lib/internal/process/next_tick.js b/lib/internal/process/next_tick.js
@@ -10,6 +10,7 @@ exports.setup = setupNextTick;
 
 function setupNextTick() {
   const promises = require('internal/process/promises');
+  const errors = require('internal/errors');
   const emitPendingUnhandledRejections = promises.setup(scheduleMicrotasks);
   var nextTickQueue = [];
   var microtasksScheduled = false;
@@ -139,7 +140,7 @@ function setupNextTick() {
 
   function nextTick(callback) {
     if (typeof callback !== 'function')
-      throw new TypeError('callback is not a function');
+      throw new errors.TypeError('ERR_INVALID_CALLBACK');
     // on the way out, don't bother. it won't get fired anyway.
     if (process._exiting)
       return;

diff --git a/lib/internal/process/stdio.js b/lib/internal/process/stdio.js
@@ -2,14 +2,25 @@
 
 exports.setup = setupStdio;
 
+var errors;
+
+function lazyErrors() {
+  if (!errors)
+    errors = require('internal/errors');
+  return errors;
+}
+
 function setupStdio() {
-  var stdin, stdout, stderr;
+  var stdin;
+  var stdout;
+  var stderr;
 
   function getStdout() {
     if (stdout) return stdout;
     stdout = createWritableStdioStream(1);
     stdout.destroy = stdout.destroySoon = function(er) {
-      er = er || new Error('process.stdout cannot be closed.');
+      const errors = lazyErrors();
+      er = er || new errors.Error('ERR_STDOUT_CLOSE');
       stdout.emit('error', er);
     };
     if (stdout.isTTY) {
@@ -22,7 +33,8 @@ function setupStdio() {
     if (stderr) return stderr;
     stderr = createWritableStdioStream(2);
     stderr.destroy = stderr.destroySoon = function(er) {
-      er = er || new Error('process.stderr cannot be closed.');
+      const errors = lazyErrors();
+      er = er || new errors.Error('ERR_STDERR_CLOSE');
       stderr.emit('error', er);
     };
     if (stderr.isTTY) {
@@ -79,7 +91,8 @@ function setupStdio() {
 
       default:
         // Probably an error on in uv_guess_handle()
-        throw new Error('Implement me. Unknown stdin file type!');
+        const errors = lazyErrors();
+        throw new errors.Error('ERR_UNKNOWN_STDIN_TYPE');
     }
 
     // For supporting legacy API we put the FD here.
@@ -163,7 +176,8 @@ function createWritableStdioStream(fd) {
 
     default:
       // Probably an error on in uv_guess_handle()
-      throw new Error('Implement me. Unknown stream file type!');
+      const errors = lazyErrors();
+      throw new errors.Error('ERR_UNKNOWN_STREAM_TYPE');
   }
 
   // For supporting legacy API we put the FD here.

diff --git a/lib/internal/process/warning.js b/lib/internal/process/warning.js
@@ -5,11 +5,18 @@ const prefix = `(${process.release.name}:${process.pid}) `;
 
 exports.setup = setupProcessWarnings;
 
+var errors;
 var fs;
 var cachedFd;
 var acquiringFd = false;
 function nop() {}
 
+function lazyErrors() {
+  if (!errors)
+    errors = require('internal/errors');
+  return errors;
+}
+
 function lazyFs() {
   if (!fs)
     fs = require('fs');
@@ -105,6 +112,7 @@ function setupProcessWarnings() {
   // process.emitWarning(error)
   // process.emitWarning(str[, type[, code]][, ctor])
   process.emitWarning = function(warning, type, code, ctor) {
+    const errors = lazyErrors();
     if (typeof type === 'function') {
       ctor = type;
       code = undefined;
@@ -115,17 +123,18 @@ function setupProcessWarnings() {
       code = undefined;
     }
     if (code !== undefined && typeof code !== 'string')
-      throw new TypeError('\'code\' must be a String');
+      throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'code', 'string');
     if (type !== undefined && typeof type !== 'string')
-      throw new TypeError('\'type\' must be a String');
+      throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'type', 'string');
     if (warning === undefined || typeof warning === 'string') {
       warning = new Error(warning);
       warning.name = String(type || 'Warning');
       if (code !== undefined) warning.code = code;
       Error.captureStackTrace(warning, ctor || process.emitWarning);
     }
     if (!(warning instanceof Error)) {
-      throw new TypeError('\'warning\' must be an Error object or string.');
+      throw new errors.TypeError('ERR_INVALID_ARG_TYPE',
+                                 'warning', ['Error', 'string']);
     }
     if (warning.name === 'DeprecationWarning') {
       if (process.noDeprecation)

diff --git a/test/parallel/test-internal-errors.js b/test/parallel/test-internal-errors.js
@@ -130,3 +130,23 @@ assert.throws(
   () => errors.E('TEST_ERROR_USED_SYMBOL'),
   /^AssertionError: Error symbol: TEST_ERROR_USED_SYMBOL was already used\.$/
 );
+
+// // Test ERR_INVALID_ARG_TYPE
+assert.strictEqual(errors.message('ERR_INVALID_ARG_TYPE', ['a', 'b']),
+                   'The "a" argument must be of type b');
+assert.strictEqual(errors.message('ERR_INVALID_ARG_TYPE', ['a', ['b']]),
+                   'The "a" argument must be of type b');
+assert.strictEqual(errors.message('ERR_INVALID_ARG_TYPE', ['a', ['b', 'c']]),
+                   'The "a" argument must be one of type b, or c');
+assert.strictEqual(errors.message('ERR_INVALID_ARG_TYPE',
+                                  ['a', ['b', 'c', 'd']]),
+                   'The "a" argument must be one of type b, c, or d');
+assert.strictEqual(errors.message('ERR_INVALID_ARG_TYPE', ['a', 'b', 'c']),
+                   'The "a" argument must be of type b. Received type string');
+assert.strictEqual(errors.message('ERR_INVALID_ARG_TYPE',
+                                  ['a', 'b', undefined]),
+                   'The "a" argument must be of type b. Received type ' +
+                   'undefined');
+assert.strictEqual(errors.message('ERR_INVALID_ARG_TYPE',
+                                  ['a', 'b', null]),
+                   'The "a" argument must be of type b. Received type null');
diff --git a/test/parallel/test-process-emitwarning.js b/test/parallel/test-process-emitwarning.js
@@ -39,16 +39,19 @@ warningThrowToString.toString = function() {
 };
 process.emitWarning(warningThrowToString);
 
+const expectedError =
+  common.expectsError({code: 'ERR_INVALID_ARG_TYPE', type: TypeError});
+
 // TypeError is thrown on invalid input
-assert.throws(() => process.emitWarning(1), TypeError);
-assert.throws(() => process.emitWarning({}), TypeError);
-assert.throws(() => process.emitWarning(true), TypeError);
-assert.throws(() => process.emitWarning([]), TypeError);
-assert.throws(() => process.emitWarning('', {}), TypeError);
-assert.throws(() => process.emitWarning('', '', {}), TypeError);
-assert.throws(() => process.emitWarning('', 1), TypeError);
-assert.throws(() => process.emitWarning('', '', 1), TypeError);
-assert.throws(() => process.emitWarning('', true), TypeError);
-assert.throws(() => process.emitWarning('', '', true), TypeError);
-assert.throws(() => process.emitWarning('', []), TypeError);
-assert.throws(() => process.emitWarning('', '', []), TypeError);
+assert.throws(() => process.emitWarning(1), expectedError);
+assert.throws(() => process.emitWarning({}), expectedError);
+assert.throws(() => process.emitWarning(true), expectedError);
+assert.throws(() => process.emitWarning([]), expectedError);
+assert.throws(() => process.emitWarning('', {}), expectedError);
+assert.throws(() => process.emitWarning('', '', {}), expectedError);
+assert.throws(() => process.emitWarning('', 1), expectedError);
+assert.throws(() => process.emitWarning('', '', 1), expectedError);
+assert.throws(() => process.emitWarning('', true), expectedError);
+assert.throws(() => process.emitWarning('', '', true), expectedError);
+assert.throws(() => process.emitWarning('', []), expectedError);
+assert.throws(() => process.emitWarning('', '', []), expectedError);