@ -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!