diff --git a/README.md b/README.md index 78646b5..78fa9c6 100644 --- a/README.md +++ b/README.md @@ -7,6 +7,43 @@ This module is used for writing unit tests for your applications, you can access It aims to be fully compatibe with the [node.js assert module](http://nodejs.org/api/assert.html), same API and same behavior, just adding support for web browsers. The API and code may contain traces of the [CommonJS Unit Testing 1.0 spec](http://wiki.commonjs.org/wiki/Unit_Testing/1.0) which they were based on, but both have evolved significantly since then. +A `strict` and a `legacy` mode exist, while it is recommended to only use `strict mode`. + +## Strict mode + +When using the `strict mode`, any `assert` function will use the equality used in the strict function mode. So `assert.deepEqual()` will, for example, work the same as `assert.deepStrictEqual()`. + +It can be accessed using: + +```js +const assert = require('assert').strict; +``` + +## Legacy mode + +> Deprecated: Use strict mode instead. + +When accessing `assert` directly instead of using the `strict` property, the +[Abstract Equality Comparison](https://tc39.github.io/ecma262/#sec-abstract-equality-comparison) will be used for any function without a +"strict" in its name (e.g. `assert.deepEqual()`). + +It can be accessed using: + +```js +const assert = require('assert'); +``` + +It is recommended to use the `strict mode` instead as the Abstract Equality Comparison can often have surprising results. Especially +in case of `assert.deepEqual()` as the used comparison rules there are very lax. + +E.g. + +```js +// WARNING: This does not throw an AssertionError! +assert.deepEqual(/a/gi, new Date()); +``` + + ## assert.fail(actual, expected, message, operator) Throws an exception that displays the values for actual and expected separated by the provided operator. diff --git a/assert.js b/assert.js index 8e52d7f..a9aa6ad 100644 --- a/assert.js +++ b/assert.js @@ -1,5 +1,7 @@ 'use strict'; +var objectAssign = require('object-assign'); + // compare and isBuffer taken from https://github.com/feross/buffer/blob/680e9e5e488f22aac27599a57dc844a6315928dd/index.js // original notice: @@ -483,6 +485,18 @@ assert.doesNotThrow = function(block, /*optional*/error, /*optional*/message) { assert.ifError = function(err) { if (err) throw err; }; +// Expose a strict only variant of assert +function strict(value, message) { + if (!value) fail(value, true, message, '==', strict); +} +assert.strict = objectAssign(strict, assert, { + equal: assert.strictEqual, + deepEqual: assert.deepStrictEqual, + notEqual: assert.notStrictEqual, + notDeepEqual: assert.notDeepStrictEqual +}); +assert.strict.strict = assert.strict; + var objectKeys = Object.keys || function (obj) { var keys = []; for (var key in obj) { diff --git a/package.json b/package.json index 1bc8353..a2a6cce 100644 --- a/package.json +++ b/package.json @@ -13,6 +13,7 @@ }, "main": "./assert.js", "dependencies": { + "object-assign": "^4.1.1", "util": "0.10.3" }, "devDependencies": { diff --git a/test.js b/test.js index 8c7c5a4..a4940e1 100644 --- a/test.js +++ b/test.js @@ -342,4 +342,19 @@ function tests (assert, what) { assert.equal(e.toString().split('\n')[0], 'AssertionError: oh no'); } }); + + test('assert - strict mode', function () { + var assertStrict = assert.strict; + + assertStrict.throws(makeBlock(assertStrict.equal, 1, true), assertStrict.AssertionError); + assertStrict.notEqual(0, false); + assertStrict.throws(makeBlock(assertStrict.deepEqual, 1, true), assertStrict.AssertionError); + assertStrict.notDeepEqual(0, false); + assertStrict.equal(assertStrict.strict, assertStrict.strict.strict); + assertStrict.equal(assertStrict.equal, assertStrict.strictEqual); + assertStrict.equal(assertStrict.deepEqual, assertStrict.deepStrictEqual); + assertStrict.equal(assertStrict.notEqual, assertStrict.notStrictEqual); + assertStrict.equal(assertStrict.notDeepEqual, assertStrict.notDeepStrictEqual); + assertStrict.equal(Object.keys(assertStrict).length, Object.keys(assert).length); + }); }