(assert-module)=

# Assert module

For XPCShell tests and mochitests, `Assert` is already present as an
instantiated global to which you can refer - you don't need to construct it
yourself. You can immediately start using `Assert.ok` and similar methods as
test assertions.

The full class documentation follows, but it is perhaps worth noting that this
API is largely identical to
[NodeJS' assert module](https://nodejs.org/api/assert.html), with some
omissions/changes including strict mode and string matching.

```{js:autoclass} Assert
:members: ok, equal, notEqual, strictEqual, notStrictEqual, deepEqual, notDeepEqual,
          greater, less, greaterOrEqual, lessOrEqual, stringContains, stringMatches,
          throws, rejects, *
```