Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/tkrotoff/throw-on
Throw on console.error/warn & fetch
https://github.com/tkrotoff/throw-on
console fetch react throw xmlhttprequest
Last synced: 17 days ago
JSON representation
Throw on console.error/warn & fetch
- Host: GitHub
- URL: https://github.com/tkrotoff/throw-on
- Owner: tkrotoff
- License: mit
- Created: 2021-12-20T18:17:45.000Z (almost 3 years ago)
- Default Branch: master
- Last Pushed: 2023-03-11T14:19:26.000Z (over 1 year ago)
- Last Synced: 2024-10-22T08:54:47.609Z (23 days ago)
- Topics: console, fetch, react, throw, xmlhttprequest
- Language: JavaScript
- Homepage:
- Size: 1.36 MB
- Stars: 24
- Watchers: 2
- Forks: 1
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# throw-on
[](https://www.npmjs.com/package/throw-on)
[](https://github.com/tkrotoff/throw-on/actions)
[](https://codeclimate.com/github/tkrotoff/throw-on/test_coverage)
[](https://bundlephobia.com/result?p=throw-on)
[](https://github.com/prettier/prettier)
[](https://github.com/airbnb/javascript)
Force console.error/warn and network requests to fail.
- Tiny: less than 100 lines of code
- No dependencies
- Fully tested
- Written in TypeScript
- Works with Node.js and browsers
- Generic: not specific to React or Jest
This is an alternative to https://github.com/ValentinH/jest-fail-on-console
## Why?
Do you have warnings like _"An update inside a test was not wrapped in act"_ or _"Can't perform a React state update on an unmounted component"_ when running or testing your React app? Are your tests performing network requests when they shouldn't?
Solution: throw whenever there is a warning (e.g. console.error/warn) or a network request that isn't mocked
- The sooner a test fails, the easier it is to fix
- Improve code quality (like an ESLint rule but at run/test time)
throw-on still displays the original console message before throwing an exception with the message `throw-on console.[METHOD]: [ORIGINAL_MESSAGE_SHORTEN]`
Result:
- before (test passes)
- after (test fails)
## Usage
### In your tests
`npm install --save-dev throw-on`
```TypeScript
// Inside jest.setup.js (Jest setupFilesAfterEnv option) for example
import {
throwOnConsole,
throwOnFetch,
throwOnXMLHttpRequestOpen
} from 'throw-on';
throwOnConsole('assert');
throwOnConsole('error');
throwOnConsole('warn');
throwOnFetch();
throwOnXMLHttpRequestOpen();
```
### In the browser
`npm install throw-on`
```TypeScript
// Inside your entry file (something like index.js, app.js, pages/_app.js)
if (process.env.NODE_ENV !== 'production') { // You probably don't want this in production
const { throwOnConsole } = await import('throw-on');
throwOnConsole('assert');
throwOnConsole('error');
throwOnConsole('warn');
}
render(, document.getElementById('app'));
```
### Make it your own
Copy-paste [throwOnConsole.ts](src/throwOnConsole.ts) and/or [throwOnFetch.ts](src/throwOnFetch.ts) and/or [throwOnXMLHttpRequestOpen.ts](src/throwOnXMLHttpRequestOpen.ts) into your source code.
### Platform support
Tested with Node.js >= 14, might work with Node.js 12.
Transpilation to ES5 (via Babel for example) is needed for non-modern browsers.
## API
```TypeScript
type Options = {
/**
* Messages to ignore (won't throw), each message to ignore can be a substring or a regex.
*
* Empty list by default.
*/
ignore?: (string | RegExp)[];
};
type ConsoleMethodName = 'assert' | 'error' | 'warn' | 'info' | 'log' | 'dir' | 'debug';
/**
* Makes console method to throw if called.
*/
function throwOnConsole(methodName: ConsoleMethodName, options: Options = {}): void;
/**
* Restores the original console method implementation.
*/
function restoreConsole(methodName: ConsoleMethodName): void;
/**
* Makes fetch to throw if called.
*/
function throwOnFetch(): void;
/**
* Restores the original fetch implementation.
*/
function restoreFetch(): void;
/**
* Makes XMLHttpRequest.open to throw if called.
*/
function throwOnXMLHttpRequestOpen(): void;
/**
* Restores the original XMLHttpRequest.open implementation.
*/
function restoreXMLHttpRequestOpen(): void;
```
## What about valid console messages?
If a `console.error()` is expected, then you should assert for it:
```TypeScript
test('should log an error', () => {
const spy = jest.spyOn(console, 'error').mockImplementation();
// ...
expect(spy).toHaveBeenCalledTimes(1);
expect(spy).toHaveBeenCalledWith('your error message');
spy.mockRestore();
});
```
## Limitations
- Be careful: it adds a line to Jest stack trace, messing up the [codeframe](https://github.com/facebook/jest/issues/8819):
```
at console. (src/throwOnConsole.ts:69:7) <===
at console.error (node_modules/@testing-library/react-hooks/lib/core/console.js:19:7)
at printWarning (node_modules/react-dom/cjs/react-dom.development.js:67:30)
at error (node_modules/react-dom/cjs/react-dom.development.js:43:5)
...
```
Use `restoreConsole()` to get the original codeframe
- Be careful: the shorten exception message does not always match the original console message (because of [React error boundary](https://reactjs.org/docs/error-boundaries.html)?)
- Libraries that console.\* exceptions [1](https://github.com/expressjs/express/blob/4.17.3/lib/application.js#L630) [2](https://github.com/expressjs/api-error-handler/blob/1.0.0/index.js#L22) introduce an infinite loop:
throw-on intercepts the console.\* call and throws an exception => the library catches the exception and console.\* it, ect.