Jest Sorted

Inspired by jest-sorted. This packages extends jest.expect with 1 custom matcher, toBeSortedBy

Examples

``js
expect([{ id: 1 }, { id: 2 }, { id: 3 }]).toBeSortedBy({ key: 'id' });
expect([{ count: '10' }, { count: '5' }]).toBeSortedBy({
key: 'count',
descending: true,
coerce: true,
});
`

Installation

With npm:

`sh
npm install -D @netly/jest-sorted-by
`

With yarn:

`sh
yarn add -D @netly/jest-sorted-by
`

Setup

$3

Add @netly/jest-sorted-by to your Jest setupFilesAfterEnv configuration. See for help

For example, add the following to your package.json at the root level. See configuring jest for more info.

`json
"jest": {
"setupFilesAfterEnv": ["@netly/jest-sorted-by"]
}
`


If you are already using another test framework, like jest-chain, then you should create a test setup file and require each of the frameworks you are using.

For example:

`js
// ./testSetup.js
require('@netly/jest-sorted-by');
require('jest-chain');
require('any other test framework libraries you are using');
`

Then in your Jest config:

`json
"jest": {
"setupTestFrameworkScriptFile": "./testSetup.js"
}
`

Usage

#### options

The following options can be passed as an object to alter the assertions behavior

- descending : boolean - Asserts the array is sorted in descending order. (Defaults to false)

`js
expect([3, 2, 1]).toBeSortedBy({ descending: true });
`

- key : string - Will use the value from the passed key in an array of objects.

`js
expect([{ id: 1 }, { id: 2 }, { id: 3 }]).toBeSortedBy({ key: 'id' });
`

- strict : boolean - Fails the assertion if a passed key option does not exist in the object. (Defaults to false) Note: will use undefined for all missing keys and equal values are considered sorted.

`js
expect([{ id: 1 }, { id: 2 }, { id: 3 }]).toBeSortedBy({
key: 'nothing',
strict: false,
});
`

- comparator : function - A custom function to use for comparison. (Default comparison is a simple greater / less than). In some cases you may want to check values are sorted by a different condition. The function will take 2 elements from the array (a,b) and should return:

- A negative number if a comes first.
- A positive number if b comes first.
- 0 if the values are sorted equally.

See the compareFunction of Array.prototype.sort for more info.

`js
const doubleDigitsFirst = (a, b) => {
if (a >= 10 && b < 10) {
return -1;
}
if (b >= 10 && a < 10) {
return 1;
}
return 0;
};

expect([10, 20, 1, 2]).toBeSortedBy({
compare: doubleDigitsFirst,
});
``