errors: make code and name properties settable

For internal errors, make `code` and `name` settable while keeping them non-own properties by default. PR-URL: nodejs#15694 Fixes: nodejs#15658 Reviewed-By: Evan Lucas <evanlucas@me.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Trott · Oct 12, 2017 · d4436a0 · d4436a0
1 parent eb7c6dc
commit d4436a0
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Showing 2 changed files with 66 additions and 25 deletions.
diff --git a/lib/internal/errors.js b/lib/internal/errors.js
@@ -11,18 +11,45 @@
 const kCode = Symbol('code');
 const messages = new Map();
 
+const { defineProperty } = Object;
+
 // Lazily loaded
 var util = null;
 
 function makeNodeError(Base) {
   return class NodeError extends Base {
     constructor(key, ...args) {
       super(message(key, args));
-      this[kCode] = this.code = key;
-      Object.defineProperty(this, 'name', {
+      defineProperty(this, kCode, {
         configurable: true,
         enumerable: false,
-        value: `${super.name} [${this[kCode]}]`,
+        value: key,
+        writable: true
+      });
+    }
+
+    get name() {
+      return `${super.name} [${this[kCode]}]`;
+    }
+
+    set name(value) {
+      defineProperty(this, 'name', {
+        configurable: true,
+        enumerable: true,
+        value,
+        writable: true
+      });
+    }
+
+    get code() {
+      return this[kCode];
+    }
+
+    set code(value) {
+      defineProperty(this, 'code', {
+        configurable: true,
+        enumerable: true,
+        value,
         writable: true
       });
     }

diff --git a/test/parallel/test-internal-errors.js b/test/parallel/test-internal-errors.js
@@ -240,40 +240,54 @@ assert.throws(
 // Test that `code` property is mutable and that changing it does not change the
 // name.
 {
-  const myError = new errors.Error('ERR_MISSING_ARGS', ['name']);
+  const myError = new errors.Error('ERR_MISSING_ARGS', ['Sterrance']);
   assert.strictEqual(myError.code, 'ERR_MISSING_ARGS');
+  assert.strictEqual(myError.hasOwnProperty('code'), false);
+  assert.strictEqual(myError.hasOwnProperty('name'), false);
+  assert.deepStrictEqual(Object.keys(myError), []);
   const initialName = myError.name;
   myError.code = 'FHQWHGADS';
   assert.strictEqual(myError.code, 'FHQWHGADS');
   assert.strictEqual(myError.name, initialName);
+  assert.deepStrictEqual(Object.keys(myError), ['code']);
   assert.ok(myError.name.includes('ERR_MISSING_ARGS'));
   assert.ok(!myError.name.includes('FHQWHGADS'));
 }
 
-// Test that `name` and `message` are mutable and that changing them alters 
-// `toString()` but not `console.log()` results, which is the behavior of
-// `Error` objects in the browser.
+// Test that `name` is mutable and that changing it alters `toString()` but not
+// `console.log()` results, which is the behavior of `Error` objects in the
+// browser. Note that `name` becomes enumerable after being assigned.
 {
-  function test(prop) {
-    let initialConsoleLog = '';
-    common.hijackStdout((data) => { initialConsoleLog += data; });
-    const myError = new errors.Error('ERR_MISSING_ARGS', ['name']);
-    const initialToString = myError.toString();
-    console.log(myError);
-    assert.notStrictEqual(initialConsoleLog, '');
+  const myError = new errors.Error('ERR_MISSING_ARGS', ['Sterrance']);
+  assert.deepStrictEqual(Object.keys(myError), []);
+  const initialToString = myError.toString();
 
-    common.restoreStdout();
+  myError.name = 'Fhqwhgads';
+  assert.deepStrictEqual(Object.keys(myError), ['name']);
+  assert.notStrictEqual(myError.toString(), initialToString);
+}
+
+// Test that `message` is mutable and that changing it alters `toString()` but
+// not `console.log()` results, which is the behavior of `Error` objects in the
+// browser. Note that `message` remains non-enumerable after being assigned.
+{
+  let initialConsoleLog = '';
+  common.hijackStdout((data) => { initialConsoleLog += data; });
+  const myError = new errors.Error('ERR_MISSING_ARGS', ['Sterrance']);
+  assert.deepStrictEqual(Object.keys(myError), []);
+  const initialToString = myError.toString();
+  console.log(myError);
+  assert.notStrictEqual(initialConsoleLog, '');
 
-    let subsequentConsoleLog = '';
-    common.hijackStdout((data) => { subsequentConsoleLog += data; });
-    myError[prop] = 'Fhqwhgads';
-    assert.notStrictEqual(myError.toString(), initialToString);
-    console.log(myError);
-    assert.strictEqual(subsequentConsoleLog, initialConsoleLog);
+  common.restoreStdout();
 
-    common.restoreStdout();
-  }
+  let subsequentConsoleLog = '';
+  common.hijackStdout((data) => { subsequentConsoleLog += data; });
+  myError.message = 'Fhqwhgads';
+  assert.deepStrictEqual(Object.keys(myError), []);
+  assert.notStrictEqual(myError.toString(), initialToString);
+  console.log(myError);
+  assert.strictEqual(subsequentConsoleLog, initialConsoleLog);
 
-  test('name');
-  test('message');
+  common.restoreStdout();
 }