.. | ||
docs/rules | ||
lib | ||
node_modules | ||
CHANGELOG.md | ||
LICENSE | ||
package.json | ||
README.md |
Installation
$ yarn add --dev eslint eslint-plugin-jest
Note: If you installed ESLint globally then you must also install
eslint-plugin-jest
globally.
Usage
Add jest
to the plugins section of your .eslintrc
configuration file. You
can omit the eslint-plugin-
prefix:
{
"plugins": ["jest"]
}
Then configure the rules you want to use under the rules section.
{
"rules": {
"jest/no-disabled-tests": "warn",
"jest/no-focused-tests": "error",
"jest/no-identical-title": "error",
"jest/prefer-to-have-length": "warn",
"jest/valid-expect": "error"
}
}
You can also tell ESLint about the environment variables provided by Jest by doing:
{
"env": {
"jest/globals": true
}
}
The behaviour of some rules (specifically no-deprecated-functions
) change
depending on the version of jest
being used.
This setting is detected automatically based off the version of the jest
package installed in node_modules
, but it can also be provided explicitly if
desired:
{
"settings": {
"jest": {
"version": 26
}
}
}
Shareable configurations
Recommended
This plugin exports a recommended configuration that enforces good testing practices.
To enable this configuration use the extends
property in your .eslintrc
config file:
{
"extends": ["plugin:jest/recommended"]
}
Style
This plugin also exports a configuration named style
, which adds some
stylistic rules, such as prefer-to-be-null
, which enforces usage of toBeNull
over toBe(null)
.
To enable this configuration use the extends
property in your .eslintrc
config file:
{
"extends": ["plugin:jest/style"]
}
See ESLint documentation for more information about extending configuration files.
All
If you want to enable all rules instead of only some you can do so by adding the
all
configuration to your .eslintrc
config file:
{
"extends": ["plugin:jest/all"]
}
While the recommended
and style
configurations only change in major versions
the all
configuration may change in any release and is thus unsuited for
installations requiring long-term consistency.
Rules
Rule | Description | Configurations | Fixable |
---|---|---|---|
consistent-test-it | Have control over test and it usages |
||
expect-expect | Enforce assertion to be made in a test body | ||
lowercase-name | Enforce lowercase test names | ||
no-alias-methods | Disallow alias methods | ||
no-commented-out-tests | Disallow commented out tests | ||
no-conditional-expect | Prevent calling expect conditionally |
||
no-deprecated-functions | Disallow use of deprecated functions | ||
no-disabled-tests | Disallow disabled tests | ||
no-duplicate-hooks | Disallow duplicate setup and teardown hooks | ||
no-export | Disallow using exports in files containing tests |
||
no-focused-tests | Disallow focused tests | ||
no-hooks | Disallow setup and teardown hooks | ||
no-identical-title | Disallow identical titles | ||
no-if | Disallow conditional logic | ||
no-interpolation-in-snapshots | Disallow string interpolation inside snapshots | ||
no-jasmine-globals | Disallow Jasmine globals | ||
no-jest-import | Disallow importing Jest | ||
no-large-snapshots | disallow large snapshots | ||
no-mocks-import | Disallow manually importing from __mocks__ |
||
no-restricted-matchers | Disallow specific matchers & modifiers | ||
no-standalone-expect | Disallow using expect outside of it or test blocks |
||
no-test-callback | Avoid using a callback in asynchronous tests | ||
no-test-prefixes | Use .only and .skip over f and x |
||
no-test-return-statement | Disallow explicitly returning from tests | ||
prefer-called-with | Suggest using toBeCalledWith() or toHaveBeenCalledWith() |
||
prefer-expect-assertions | Suggest using expect.assertions() OR expect.hasAssertions() |
||
prefer-hooks-on-top | Suggest having hooks before any test cases | ||
prefer-spy-on | Suggest using jest.spyOn() |
||
prefer-strict-equal | Suggest using toStrictEqual() |
||
prefer-to-be-null | Suggest using toBeNull() |
||
prefer-to-be-undefined | Suggest using toBeUndefined() |
||
prefer-to-contain | Suggest using toContain() |
||
prefer-to-have-length | Suggest using toHaveLength() |
||
prefer-todo | Suggest using test.todo |
||
require-to-throw-message | Require a message for toThrow() |
||
require-top-level-describe | Require test cases and hooks to be inside a describe block |
||
valid-describe | Enforce valid describe() callback |
||
valid-expect | Enforce valid expect() usage |
||
valid-expect-in-promise | Enforce having return statement when testing with promises | ||
valid-title | Enforce valid titles |
Credit
Related Projects
eslint-plugin-jest-formatting
This project aims to provide formatting rules (auto-fixable where possible) to ensure consistency and readability in jest test suites.
https://github.com/dangreenisrael/eslint-plugin-jest-formatting