vitest-fail-on-console

Utility to make vitest tests fail when console.error(), console.warn(), etc. are used

What problem is this solving?

Vitest doesn't fail the tests when there is a console.error. In large codebase, we can end up with the test output overloaded by a lot of errors, warnings, etc.. To prevent this, we want to fail each test that is logging to the console. We also want to conserve a clear output of the original error.

This is what this utility is doing.

How this project is different from jest-fail-on-console?

There is several changes between jest-fail-on-console and vitest-fail-on-console:

• TypeScript typed functions, arguments, and variables - see types.ts
• refactoring of the whole codebase
• refactoring of test/specs

This repository has been developed and publish to keep and maintain a Vitest version of the original idea behind jest-fail-on-console credited at the bottom of this file.

Install

yarn add -D vitest-fail-on-console

or

npm install -D vitest-fail-on-console

How to use

In a file used in the setupFiles option of Vitest's config file (vitest.config.ts), add this code:

// tests/setup.ts
import failOnConsole from 'vitest-fail-on-console'

failOnConsole()

// or with options:
failOnConsole({
  shouldFailOnWarn: false,
})

// vitest.config.ts
import { defineConfig } from "vitest/config";
export default defineConfig({
    test: {
        environment: "node",
        setupFiles: ["tests/setup.ts"],
    },
});

But I have some expected console errors/warning

If a console.error() is expected, then you should assert for it:

test('should log an error', () => {
  vi.spyOn(console, 'error').mockImplementation(() => {})
  // do your logic
  expect(console.error).toHaveBeenCalledWith('your error message')
})

Options

You can pass an object with options to the function:

errorMessage

Use this if you want to override the default error message of this library.

// signature
type errorMessage = (
  methodName: 'assert' | 'debug' | 'error' | 'info' | 'log' | 'warn',
  bold: (string: string) => string
) => string

shouldFailOnAssert

Use this to make a test fail when a console.assert() is logged.

• Type: boolean
• Default: false

shouldFailOnDebug

Use this to make a test fail when a console.debug() is logged.

• Type: boolean
• Default: false

shouldFailOnError

Use this to make a test fail when a console.error() is logged.

• Type: boolean
• Default: true

shouldFailOnInfo

Use this to make a test fail when a console.info() is logged.

• Type: boolean
• Default: false

shouldFailOnLog

Use this to make a test fail when a console.log() is logged.

• Type: boolean
• Default: false

shouldFailOnWarn

Use this to make a test fail when a console.warn() is logged.

• Type: boolean
• Default: true

silenceMessage

// signature
type silenceMessage = (
  message: string,
  methodName: 'assert' | 'debug' | 'error' | 'info' | 'log' | 'warn'
) => boolean

This function is called for every console method supported by this utility. If true is returned, the message will not show in the console and the test won't fail.

Example:

failOnConsole({
  silenceMessage: (errorMessage) => {
    if (/Not implemented: navigation/.test(errorMessage)) {
      return true
    }
    return false
  },
})

skipTest

Use this if you want to ignore checks introduced by this library for specific tests determined by the return of the callback function. Return false if you do not want to skip console checks for the specific test and return true if you would like to skip it.

const ignoreList = [/.*components\/SomeComponent.test.tsx/]
const ignoreNameList = ['some component some test name']

failOnConsole({
  skipTest: ({ testPath, testName }) => {
    for (const pathExp of ignoreList) {
      const result = pathExp.test(testPath)
      if (result) return true
    }

    if (ignoreNameList.includes(testName)) {
      return true
    }
    
    return false
  },
})

afterEachDelay

Use this to make sure test fails even when the console warning is called after the test finished executing. This is useful for debugging flaky tests. It's recommended to turn it off for CI (or set it to a low value) as it will slow down test execution

• Type: number
• Default: 0

failOnConsole({
  afterEachDelay: !process.env.CI ? 1000 : 0,
})

License

MIT

Credits

Most of the logic is taken from :

• React's setupTests file
• jest-fail-on-console