---


Problem

In many testing libraries it is possible to supply a custom message for a given expectation, this is currently not
possible in Jest.

For example:

``js
test('returns 2 when adding 1 and 1', () => {
expect(1 + 1, 'Woah this should be 2!').toBe(3);
});
`

This will throw the following error in Jest:

`sh
Expect takes at most one argument.
`

Solution

jest-expect-message allows you to call expect with a second argument of a String message.

For example the same test as above:

`js
test('returns 2 when adding 1 and 1', () => {
expect(1 + 1, 'Woah this should be 2!').toBe(3);
});
`

With jest-expect-message this will fail with your custom error message:

`sh
● returns 2 when adding 1 and 1

Custom message:
Woah this should be 2!

expect(received).toBe(expected) // Object.is equality

Expected: 3
Received: 2
`

Installation

With npm:
`sh
npm install --save-dev jest-expect-message
`

With yarn:
`sh
yarn add -D jest-expect-message
`

Setup

Add jest-expect-message to your Jest setupFilesAfterEnv configuration.
See for help

$3

`json
"jest": {
"setupFilesAfterEnv": ["jest-expect-message"]
}
`

$3

`json
"jest": {
"setupTestFrameworkScriptFile": "jest-expect-message"
}
`

Usage

- expect(actual, message)
- actual: The value you would normally pass into an expect to assert against with a given matcher.
- message: String, the custom message you want to be printed should the expect fail.

`js
test('returns 2 when adding 1 and 1', () => {
expect(1 + 1, 'Woah this should be 2!').toBe(3);
});
``

Contributors

|
_{Matt Phillips}
💻 📖 💡 🤔 🚇") ⚠️ 🔧 |
_{Alex Neo}
💻 |
| :---: | :---: |

LICENSE

MIT