errors: improve the description of ERR_INVALID_ARG_VALUE

joyeecheung · MylesBorins · commit 9cb3f10315ed · 2018-02-26T18:34:19.000-05:00
- Allow user to customize why the argument is invalid - Display the argument with util.inspect so null bytes can be displayed properly. Backport-PR-URL: #18916 PR-URL: #18358 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Jon Moss <me@jonathanmoss.me>
diff --git a/lib/internal/errors.js b/lib/internal/errors.js
@@ -17,7 +17,13 @@ const { kMaxLength } = process.binding('buffer');
 const { defineProperty } = Object;
 
 // Lazily loaded
-var util = null;
+var util_ = null;
+function lazyUtil() {
+  if (!util_) {
+    util_ = require('util');
+  }
+  return util_;
+}
 
 function makeNodeError(Base) {
   return class NodeError extends Base {
@@ -68,11 +74,11 @@ class AssertionError extends Error {
     if (message) {
       super(message);
     } else {
+      const util = lazyUtil();
       if (actual && actual.stack && actual instanceof Error)
         actual = `${actual.name}: ${actual.message}`;
       if (expected && expected.stack && expected instanceof Error)
         expected = `${expected.name}: ${expected.message}`;
-      if (util === null) util = require('util');
       super(`${util.inspect(actual).slice(0, 128)} ` +
         `${operator} ${util.inspect(expected).slice(0, 128)}`);
     }
@@ -107,7 +113,7 @@ function message(key, args) {
   if (typeof msg === 'function') {
     fmt = msg;
   } else {
-    if (util === null) util = require('util');
+    const util = lazyUtil();
     fmt = util.format;
     if (args === undefined || args.length === 0)
       return msg;
@@ -263,8 +269,14 @@ E('ERR_INSPECTOR_CLOSED', 'Session was closed');
 E('ERR_INSPECTOR_NOT_AVAILABLE', 'Inspector is not available');
 E('ERR_INSPECTOR_NOT_CONNECTED', 'Session is not connected');
 E('ERR_INVALID_ARG_TYPE', invalidArgType);
-E('ERR_INVALID_ARG_VALUE', (name, value) =>
-  `The value "${String(value)}" is invalid for argument "${name}"`);
+E('ERR_INVALID_ARG_VALUE', (name, value, reason = 'is invalid') => {
+  const util = lazyUtil();
+  let inspected = util.inspect(value);
+  if (inspected.length > 128) {
+    inspected = inspected.slice(0, 128) + '...';
+  }
+  return `The argument '${name}' ${reason}. Received ${inspected}`;
+}),
 E('ERR_INVALID_ARRAY_LENGTH',
   (name, len, actual) => {
     internalAssert(typeof actual === 'number', 'actual must be a number');
diff --git a/test/parallel/test-internal-errors.js b/test/parallel/test-internal-errors.js
@@ -334,10 +334,20 @@ assert.strictEqual(
 }
 
 {
-  const error = new errors.Error('ERR_INVALID_ARG_VALUE', 'foo', 'bar');
+  const error = new errors.Error('ERR_INVALID_ARG_VALUE', 'foo', '\u0000bar');
   assert.strictEqual(
     error.message,
-    'The value "bar" is invalid for argument "foo"'
+    'The argument \'foo\' is invalid. Received \'\\u0000bar\''
+  );
+}
+
+{
+  const error = new errors.Error(
+    'ERR_INVALID_ARG_VALUE',
+    'foo', { a: 1 }, 'must have property \'b\'');
+  assert.strictEqual(
+    error.message,
+    'The argument \'foo\' must have property \'b\'. Received { a: 1 }'
   );
 }
 
