Node.js Assert Module
Example
If an expression evaluates to 0 or false, an error is thrown and the program is terminated:
var assert = require('assert');
assert(5 > 7);
Run example »
Definition and Usage
The assert module provides a way of testing expressions. If the expression evaluates to 0, or false, an assertion failure is being caused, and the program is terminated.
This module was built to be used internally by Node.js.
Syntax
The syntax for including the assert module in your application:
var assert = require('assert');
Assert Methods
| Method | Description |
|---|---|
| assert() | Checks if a value is true. Same as assert.ok() |
| deepEqual() | Checks if two values are equal |
| deepStrictEqual() | Checks if two values are equal, using the strict equal operator (===) |
| doesNotThrow() | |
| equal() | Checks if two values are equal, using the equal operator (==) |
| fail() | Throws an Assertion Error |
| ifError() | Throws a specified error if the specified error evaluates to true |
| notDeepEqual() | Checks if two values are not equal |
| notDeepStrictEqual() | Checks if two values are not equal, using the strict not equal operator (!==) |
| notEqual() | Checks if two values are not equal, using the not equal operator (!=) |
| notStrictEqual() | Checks if two values are not equal, using the strict not equal operator (!==) |
| ok() | Checks if a value is true |
| strictEqual() | Checks if two values are equal, using the strict equal operator (===) |
| throws() |
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