# node-assert-plus **Repository Path**: mirrors_addons/node-assert-plus ## Basic Information - **Project Name**: node-assert-plus - **Description**: Extra assertions on top of node's assert module - **Primary Language**: Unknown - **License**: MIT - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2020-05-03 - **Last Updated**: 2025-08-16 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # assert-plus This library is a thin wrapper over the Node built-in `assert` module, providing two main enhancements: 1. the ability to disable assertions with the environment variable `NODE_NDEBUG` 2. some API wrappers for argument testing; e.g., `assert.string(myArg, 'myArg')`. As a simple example: ```javascript var assert = require('assert-plus'); function fooAccount(options, callback) { assert.object(options, 'options'); assert.number(options.id, 'options.id'); assert.bool(options.isManager, 'options.isManager'); assert.string(options.name, 'options.name'); assert.arrayOfString(options.email, 'options.email'); assert.func(callback, 'callback'); // Do stuff callback(null, {}); } ``` See [CONTRIBUTING.md](CONTRIBUTING.md) for details on how to submit changes. ## API All methods that *aren't* part of node's core assert API are simply assumed to take an argument, and then a string 'name' that's not a message; `AssertionError` will be thrown if the assertion fails with a message like: AssertionError: foo (string) is required at test (/home/mark/work/foo/foo.js:3:9) at Object. (/home/mark/work/foo/foo.js:15:1) at Module._compile (module.js:446:26) at Object..js (module.js:464:10) at Module.load (module.js:353:31) at Function._load (module.js:311:12) at Array.0 (module.js:484:10) at EventEmitter._tickCallback (node.js:190:38) from: ```javascript function test(foo) { assert.string(foo, 'foo'); } ``` There you go. You can check that arrays are of a homogeneous type with `Arrayof$Type`: ```javascript function test(foo) { assert.arrayOfString(foo, 'foo'); } ``` You can assert IFF an argument is not `undefined` (i.e., an optional arg): ```javascript assert.optionalString(foo, 'foo'); ``` Lastly, you can opt-out of assertion checking altogether by setting the environment variable `NODE_NDEBUG=1`. This is pseudo-useful if you have lots of assertions, and don't want to pay `typeof ()` taxes to v8 in production. Be advised: The standard functions re-exported from `assert` are also disabled in assert-plus if NDEBUG is specified. Using them directly from the `assert` module avoids this behavior. The complete list of APIs is: * `assert.array` * `assert.bool` * `assert.buffer` * `assert.func` * `assert.number` * `assert.finite` * `assert.object` * `assert.string` * `assert.stream` * `assert.date` * `assert.regexp` * `assert.uuid` * `assert.arrayOfArray` * `assert.arrayOfBool` * `assert.arrayOfBuffer` * `assert.arrayOfFunc` * `assert.arrayOfNumber` * `assert.arrayOfFinite` * `assert.arrayOfObject` * `assert.arrayOfString` * `assert.arrayOfStream` * `assert.arrayOfDate` * `assert.arrayOfRegexp` * `assert.arrayOfUuid` * `assert.optionalArray` * `assert.optionalBool` * `assert.optionalBuffer` * `assert.optionalFunc` * `assert.optionalNumber` * `assert.optionalFinite` * `assert.optionalObject` * `assert.optionalString` * `assert.optionalStream` * `assert.optionalDate` * `assert.optionalRegexp` * `assert.optionalUuid` * `assert.optionalArrayOfArray` * `assert.optionalArrayOfBool` * `assert.optionalArrayOfBuffer` * `assert.optionalArrayOfFunc` * `assert.optionalArrayOfNumber` * `assert.optionalArrayOfFinite` * `assert.optionalArrayOfObject` * `assert.optionalArrayOfString` * `assert.optionalArrayOfStream` * `assert.optionalArrayOfDate` * `assert.optionalArrayOfRegexp` * `assert.optionalArrayOfUuid` * `assert.AssertionError` * `assert.fail` * `assert.ok` * `assert.equal` * `assert.notEqual` * `assert.deepEqual` * `assert.notDeepEqual` * `assert.strictEqual` * `assert.notStrictEqual` * `assert.throws` * `assert.doesNotThrow` * `assert.ifError` ## Installation npm install assert-plus ## License The MIT License (MIT) Copyright (c) 2018, Joyent, Inc. and assert-plus authors Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.