From c93e2678f0c896c9d7f85b2174ec307601373fb8 Mon Sep 17 00:00:00 2001 From: Brian White Date: Thu, 15 Oct 2015 15:55:42 -0400 Subject: [PATCH] util: fix constructor/instanceof checks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit These new checks are similar to the one introduced in 089d68861, but for other types of objects. Specifically, if an object was created in a different context, the constructor object will not be the same as the constructor object in the current context, so we have to compare constructor names instead. PR-URL: https://github.com/nodejs/node/pull/3385 Reviewed-By: Evan Lucas Reviewed-By: James M Snell Reviewed-By: Michaƫl Zasso --- lib/util.js | 20 ++++++++++++-------- test/parallel/test-util-inspect.js | 10 ++++++++++ 2 files changed, 22 insertions(+), 8 deletions(-) diff --git a/lib/util.js b/lib/util.js index 0ccfca0304af9c..c07edfe87d6405 100644 --- a/lib/util.js +++ b/lib/util.js @@ -198,6 +198,7 @@ function ensureDebugIsInitialized() { function inspectPromise(p) { ensureDebugIsInitialized(); + // Only create a mirror if the object is a Promise. if (!binding.isPromise(p)) return null; const mirror = Debug.MakeMirror(p, true); @@ -292,16 +293,19 @@ function formatValue(ctx, value, recurseTimes) { var constructor = getConstructorOf(value); var base = '', empty = false, braces, formatter; + // We can't compare constructors for various objects using a comparison like + // `constructor === Array` because the object could have come from a different + // context and thus the constructor won't match. Instead we check the + // constructor names (including those up the prototype chain where needed) to + // determine object types. if (Array.isArray(value)) { - // We can't use `constructor === Array` because this could - // have come from a Debug context. - // Otherwise, an Array will print "Array [...]". + // Unset the constructor to prevent "Array [...]" for ordinary arrays. if (constructor && constructor.name === 'Array') constructor = null; braces = ['[', ']']; empty = value.length === 0; formatter = formatArray; - } else if (value instanceof Set) { + } else if (objectToString(value) === '[object Set]') { braces = ['{', '}']; // With `showHidden`, `length` will display as a hidden property for // arrays. For consistency's sake, do the same for `size`, even though this @@ -310,7 +314,7 @@ function formatValue(ctx, value, recurseTimes) { keys.unshift('size'); empty = value.size === 0; formatter = formatSet; - } else if (value instanceof Map) { + } else if (objectToString(value) === '[object Map]') { braces = ['{', '}']; // Ditto. if (ctx.showHidden) @@ -318,8 +322,7 @@ function formatValue(ctx, value, recurseTimes) { empty = value.size === 0; formatter = formatMap; } else { - // Only create a mirror if the object superficially looks like a Promise. - var promiseInternals = value instanceof Promise && inspectPromise(value); + var promiseInternals = inspectPromise(value); if (promiseInternals) { braces = ['{', '}']; formatter = formatPromise; @@ -335,7 +338,8 @@ function formatValue(ctx, value, recurseTimes) { empty = false; formatter = formatCollectionIterator; } else { - if (constructor === Object) + // Unset the constructor to prevent "Object {...}" for ordinary objects. + if (constructor && constructor.name === 'Object') constructor = null; braces = ['{', '}']; empty = true; // No other data than keys. diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js index 320d5e444ad80a..5831c40e77e930 100644 --- a/test/parallel/test-util-inspect.js +++ b/test/parallel/test-util-inspect.js @@ -141,6 +141,16 @@ for (const o of vals) { assert.strictEqual(util.inspect(valsOutput), '[ [ 1, 2 ] ]'); +// test for other constructors in different context +var obj = require('vm').runInNewContext('(function(){return {}})()', {}); +assert.strictEqual(util.inspect(obj), '{}'); +obj = require('vm').runInNewContext('var m=new Map();m.set(1,2);m', {}); +assert.strictEqual(util.inspect(obj), 'Map { 1 => 2 }'); +obj = require('vm').runInNewContext('var s=new Set();s.add(1);s.add(2);s', {}); +assert.strictEqual(util.inspect(obj), 'Set { 1, 2 }'); +obj = require('vm').runInNewContext('fn=function(){};new Promise(fn,fn)', {}); +assert.strictEqual(util.inspect(obj), 'Promise { }'); + // test for property descriptors var getter = Object.create(null, { a: {