util: fix iterable types with special prototype

The fallback should only be taken for a null prototype. If an iterable data type (e.g., Array) has a prototype without `Symbol.iterator`, just try the best to visualize it as object. PR-URL: #25457 Fixes: #25451 Reviewed-By: Gus Caplan <[email protected]> Reviewed-By: Anto Aravinth <[email protected]> Reviewed-By: James M Snell <[email protected]>
nodejs · Jan 23, 2019 · 338f456 · 338f456
1 parent 4c207d9
commit 338f456
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Showing 2 changed files with 22 additions and 16 deletions.
diff --git a/lib/internal/util/inspect.js b/lib/internal/util/inspect.js
@@ -463,28 +463,22 @@ function clazzWithNullPrototype(clazz, name) {
 function noPrototypeIterator(ctx, value, recurseTimes) {
  let newVal;
  if (isSet(value)) {
- const clazz = Object.getPrototypeOf(value) ||
- clazzWithNullPrototype(Set, 'Set');
+ const clazz = clazzWithNullPrototype(Set, 'Set');
  newVal = new clazz(setValues(value));
  } else if (isMap(value)) {
- const clazz = Object.getPrototypeOf(value) ||
- clazzWithNullPrototype(Map, 'Map');
+ const clazz = clazzWithNullPrototype(Map, 'Map');
  newVal = new clazz(mapEntries(value));
  } else if (Array.isArray(value)) {
- const clazz = Object.getPrototypeOf(value) ||
- clazzWithNullPrototype(Array, 'Array');
+ const clazz = clazzWithNullPrototype(Array, 'Array');
  newVal = new clazz(value.length);
  } else if (isTypedArray(value)) {
- let clazz = Object.getPrototypeOf(value);
- if (!clazz) {
- const constructor = findTypedConstructor(value);
- clazz = clazzWithNullPrototype(constructor, constructor.name);
- }
+ const constructor = findTypedConstructor(value);
+ const clazz = clazzWithNullPrototype(constructor, constructor.name);
  newVal = new clazz(value);
  }
- if (newVal) {
+ if (newVal !== undefined) {
  Object.defineProperties(newVal, Object.getOwnPropertyDescriptors(value));
- return formatValue(ctx, newVal, recurseTimes);
+ return formatRaw(ctx, newVal, recurseTimes);
  }
 }
 
@@ -728,9 +722,11 @@ function formatRaw(ctx, value, recurseTimes, typedArray) {
  } else {
  // The input prototype got manipulated. Special handle these. We have to
  // rebuild the information so we are able to display everything.
- const specialIterator = noPrototypeIterator(ctx, value, recurseTimes);
- if (specialIterator) {
- return specialIterator;
+ if (constructor === null) {
+ const specialIterator = noPrototypeIterator(ctx, value, recurseTimes);
+ if (specialIterator) {
+ return specialIterator;
+ }
  }
  if (isMapIterator(value)) {
  braces = [`[${tag || 'Map Iterator'}] {`, '}'];

diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
@@ -1853,6 +1853,16 @@ assert.strictEqual(
  util.inspect(new StorageObject()),
  '<[Object: null prototype] {}> {}'
  );
+
+ obj = [1, 2, 3];
+ Object.setPrototypeOf(obj, Number.prototype);
+ assert.strictEqual(inspect(obj), "Number { '0': 1, '1': 2, '2': 3 }");
+
+ Object.setPrototypeOf(obj, Object.create(null));
+ assert.strictEqual(
+ inspect(obj),
+ "<[Object: null prototype] {}> { '0': 1, '1': 2, '2': 3 }"
+ );
 }
 
 // Check that the fallback always works.