@giancosta86/more-jest
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TypeScript utilities for Jest
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# more-jest
_TypeScript utilities for Jest_
[](https://badge.fury.io/js/@giancosta86%2Fmore-jest)
[](/LICENSE)
**more-jest** is a TypeScript library providing enhanced TypeScript support for Jest.
## Installation
The package on NPM is:
> @giancosta86/omnicourse
The public API entirely resides in the root package index, so you shouldn't reference specific modules.
### Matchers
To use the matchers provided by `more-jest` within a project, one needs to:
1. Add the following attribute to the object exported by `jest.config.js`:
```typescript
setupFilesAfterEnv: ["@giancosta86/more-jest/dist/all"],
```
1. Add this line to a `global.d.ts` file within the project root directory:
```typescript
import "@giancosta86/more-jest";
```
1. Add `"./global.d.ts"` to the `include` array in `tsconfig.json`
## Usage
### Equality.addTesterFor(classType)
Takes a parameter of class `T` containing a method defined as:
```typescript
equals(other: T): boolean {}
```
and registers into Jest an _equality tester_ that:
- returns `undefined` if either equality operand is not an instance of class `T`
- otherwise, returns calls `optionalEquals()` as defined by [@giancosta86/swanlake](https://github.com/giancosta86/swan-lake)
### Equality.test
Runs a suite of equality-related tests, inside a `describe` block having title «equality».
It takes the following parameters:
- a factory used to create a **reference object** and its _equal copies_
- a factory used to create a **different object**, not equal to the reference instance
### Comparison.test
Runs a suite of comparison-related tests based on a `Comp` algorithm, within a «comparison» `describe` block.
It takes an object with the following parameters:
- `comp`: the `Comp` object to be tested
- `scrambledItems`: the items in any chaotic state
- `sortedItems`: the items in the expected order
### Matchers
- `.toBeTrimmed()`: expects that a string be trimmed
- `.toEqualSequence(expected)`: expects that an iterable has the same items, in the same order, as the given iterable. The iterables can be of different types
- `.toHaveSameJson(expected)`: expects that a value be serialized to JSON as the given object
## See also
- [swan-lake](https://github.com/giancosta86/swan-lake)
- [more-jest-io](https://github.com/giancosta86/more-jest-io) - this library's **I/O**-related counterpart
- [jest-extended](https://jest-extended.jestcommunity.dev/) - Additional Jest matchers