Vitest Fail on Console Utility

0.10.1 · active · verified Sun Apr 19

vitest-fail-on-console is a utility library for Vitest that enhances test reliability by automatically failing tests that emit `console.error()` or `console.warn()` messages. This prevents critical debugging information from being overlooked in large test suites and ensures that all console outputs are intentional or properly handled. Currently at version 0.10.1, the library maintains an active development pace with several releases occurring within a few months, indicating consistent updates and bug fixes. Unlike its Jest counterpart, `jest-fail-on-console`, this library is specifically refactored and typed with TypeScript for the Vitest ecosystem, providing robust type safety and a streamlined developer experience. It offers granular control over which console methods trigger failures and allows for custom messaging and conditional message allowances, ensuring flexibility for expected console outputs while enforcing strict logging discipline.

Common errors

```
TypeError: default is not a function
```
cause Attempting to import `failOnConsole` as a named export (e.g., `{ failOnConsole }`) or using CommonJS `require()` when the package is primarily an ESM default export.

fix Change your import statement to `import failOnConsole from 'vitest-fail-on-console';`.
```
Cannot find module 'vitest-fail-on-console' or its corresponding type declarations.
```
cause Module resolution failure due to incorrect `tsconfig.json` settings, outdated package version, or improper `package.json` exports configuration on older environments.

fix Update `vitest-fail-on-console` to the latest version. Verify `tsconfig.json` includes `"moduleResolution": "bundler"` or `"nodenext"` and `"module": "esnext"` (or similar for Vitest compatibility).
```
Test failed due to console.error being called: [your error message here]
```
cause A test executed code that resulted in `console.error()` (or `console.warn()`, `console.log()` etc., depending on configuration) being called, and this output was not explicitly allowed or mocked.

fix If the message is expected, use `vi.spyOn(console, 'error').mockImplementation(() => {})` and `expect(console.error).toHaveBeenCalledWith(...)` within your test, or configure the `allowMessage` option in `failOnConsole` to permit that specific message.

Warnings

gotcha When migrating or upgrading, users might encounter 'TypeError: default is not a function' if they attempt to import `failOnConsole` as a named export or use CommonJS `require()` syntax. The library is primarily designed for ESM default imports.
Fix: Ensure you are using `import failOnConsole from 'vitest-fail-on-console';` in your setup file. If using older module systems, consult the `package.json` 'main' or 'exports' fields for compatibility.
gotcha Older versions (0.6.1, 0.6.2) experienced 'Cannot find module 'vitest-fail-on-console'' errors, indicating module resolution issues. This could recur with misconfigured `tsconfig.json` or bundlers.
Fix: Update to the latest version of `vitest-fail-on-console`. Verify your `tsconfig.json` `moduleResolution` and `module` settings are compatible with Vitest's ESM-first approach, typically using 'bundler' or 'nodenext'.
gotcha This utility requires specific peer dependencies including `@vitest/utils`, `vite`, and `vitest` at minimum specified versions. Incompatible versions can lead to runtime errors or unexpected behavior.
Fix: Ensure that your project's `devDependencies` for `@vitest/utils`, `vite`, and `vitest` meet or exceed the versions specified in `vitest-fail-on-console`'s peer dependencies (e.g., `"@vitest/utils": ">=0.26.2"`).
gotcha By default, `console.error()` and `console.warn()` will fail tests. If these are expected outputs, tests will fail unless explicitly mocked, spied upon, or allowed via options.
Fix: For expected outputs, use `vi.spyOn(console, 'error').mockImplementation(() => {})` and assert its calls, or utilize the `allowMessage` option to permit specific console messages to pass without failing the test.
gotcha Version 0.6.0 included a security update to package dependencies. While no specific CVE was detailed, it highlights the importance of keeping the utility updated to benefit from security patches in underlying packages.
Fix: Regularly update `vitest-fail-on-console` and its related peer dependencies to their latest stable versions to ensure you receive critical fixes and security enhancements.

Install

npm install vitest-fail-on-console npm
yarn add vitest-fail-on-console yarn
pnpm add vitest-fail-on-console pnpm

Imports

failOnConsole

wrong:

import { failOnConsole } from 'vitest-fail-on-console';
const failOnConsole = require('vitest-fail-on-console');

correct:

import failOnConsole from 'vitest-fail-on-console';

The utility is exported as a default function. Use standard ESM default import syntax in Vitest setup files.

Quickstart

Demonstrates how to integrate `vitest-fail-on-console` into a Vitest project using `setupFiles` in `vitest.config.ts` to automatically fail tests on specified console outputs, including basic configuration and custom message allowance.

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

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

// Enable failure on console.error and console.warn by default
failOnConsole();

// Or with custom options, e.g., to only fail on errors and allow specific warnings
failOnConsole({
  shouldFailOnWarn: false, // Don't fail on warnings
  allowMessage: (message, methodName) => {
    if (methodName === 'warn' && message.includes('Expected warning')) {
      return true; // Allow specific warning messages to pass without failing the test
    }
    return false;
  }
});

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