Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/philschatz/fetch-vcr
:vhs: Stop mocking HTTP Requests! Just record and then play them back
https://github.com/philschatz/fetch-vcr
Last synced: 3 months ago
JSON representation
:vhs: Stop mocking HTTP Requests! Just record and then play them back
- Host: GitHub
- URL: https://github.com/philschatz/fetch-vcr
- Owner: philschatz
- Created: 2017-05-12T22:50:12.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2023-01-03T15:15:06.000Z (about 2 years ago)
- Last Synced: 2024-10-13T16:43:39.923Z (3 months ago)
- Language: JavaScript
- Homepage: https://philschatz.com/2017/05/15/record-fetch-requests/
- Size: 1.03 MB
- Stars: 33
- Watchers: 3
- Forks: 11
- Open Issues: 23
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# fetch-vcr
[![gh-board][kanban-image]][kanban-url]
[![NPM version][npm-image]][npm-url]
[![Downloads][downloads-image]][downloads-url]
[![build status][travis-image]][travis-url]
[![dependency status][dependency-image]][dependency-url]
[![dev dependency status][dev-dependency-image]][dev-dependency-url]
Stop mocking HTTP Requests. Just record and then play them back. See [vcr/vcr](https://github.com/vcr/vcr) for the main idea.
# Usage
After setting up (see below), the basics are:
1. set the `VCR_MODE=cache` environment variable before running your tests
2. run your tests
This will record (and load) all the HTTP responses into the `./_fixtures/` directory.
And when you run the steps again, viola! no network traffic happens.
# What are the different modes?
- `playback`: (default) **only** uses the local fixture files
- `cache`: tries to use the recorded response and if not found then it is fetched and then saved (useful when adding new tests)
- `record`: forces HTTP requests and responses are saved to the filesystem (useful for regenerating all the fixtures)
# How can I set the VCR mode?
You can set the mode either by:
- setting the `VCR_MODE=record` environment variable when running tests (NodeJS)
- explicitly running `fetch.configure({mode: 'record'})` (NodeJS or browser)
# How do I set this up?
There are separate examples for NodeJS, Jest, and in a browser (PhantomJS or Selenium)
## NodeJS Setup
Here is how you would use it in a typical NodeJS app:
```js
// import fetch from 'fetch';
import fetch from 'fetch-vcr';
// Configure where the recordings should be loaded/saved to.
// The path is relative to `process.cwd()` but can be absolute.
fetch.configure({
fixturePath: './_fixtures',
// mode: 'record' <-- This is optional
})
// Use fetch like you would normally
fetch('http://openstax.org')
.then(response => {
console.log(response.ok)
})
```
## How do I ignore calls?
Here is how you would configure it to ignore certain request:
```js
// import fetch from 'fetch';
import fetch from 'fetch-vcr';
// Configure where the recordings should be loaded/saved to.
// The path is relative to `process.cwd()` but can be absolute.
fetch.configure({
fixturePath: './_fixtures',
ignoreUrls: [/.+weedmaps\.com.+/] // <-- This is an array of Regular Expressions
// mode: 'record' <-- This is optional
})
fetch('https://weedmaps.com/sitemap') // <-- This will be ignored from vcr
.then(response => {
console.log(response)
})
```
## How can I tell if the response was from the cache?
You can check `response.wasCached`. It will be `true` if the response was loaded from the cache.
```js
import fetch from 'fetch-vcr';
fetch('https://philschatz.com').then(response => {
if (!response.wasCached) {
sleep(1000) // wait before making another request
}
})
```
## Jest Setup
Just add the following to `package.json`:
```
"jest": {
"moduleNameMapper": {
"hack-node-fetch": "node-fetch",
"node-fetch": "fetch-vcr"
}
}
```
If you want to check which calls were made, you can use the following:
```js
// Returns an array of {url, args, hash, bodyFilename, response, optionsFilename}
const allCalls = fetchVCR.getCalled()
// Clears the array of calls made
fetchVCR.clearCalled()
```
## jsdom Setup
Many apps use `jsdom` for testing which makes it really easy to add `fetch-vcr`. Just replace the global `fetch` function with `fetchVCR` and you can record/play back the cassettes. See below for an example:
```js
var fs = require('fs')
var jsdom = require('jsdom')
var fetchVCR = require('fetch-vcr')
// Configure the path to find cassettes
fetchVCR.configure({
fixturePath: './_fixtures/'
})
var dom = new jsdom.JSDOM(fs.readFileSync('./jsdom-example.html'), {
runScripts: 'dangerously',
beforeParse: (window) => {
// This changes the fetch global to be fetchVCR
window.fetch = fetchVCR
}
})
```
## How can I use this in a browser?
It is easy to record HTTP requests in NodeJS and play them back in the browser.
To play them back in a browser, just run `fetchVCR.configure({fixturePath: './path/to/_fixtures'})` and `fetchVCR` will use that path to load the files via AJAX requests.
To record HTTP requests in a browser you will need to do a little bit of work. Loading fixture files is relatively painless (using `XMLHTTPRequest`) but saving them to disk is non-trivial.
In order to save the fixture files to disk you will need to override `fetchVCR.saveFile(rootPath, filename, contents) => Promise`.
If you are using PhantomJS you will likely need to use the `alert(msg)` to get data out of PhantomJS and then save it to the filesystem (using `fs.writeFile(...)`)
[kanban-image]: https://img.shields.io/github/issues/philschatz/fetch-vcr.svg?label=kanban%20board%20%28gh-board%29
[kanban-url]: http://philschatz.com/gh-board/#/r/philschatz:fetch-vcr
[npm-image]: https://img.shields.io/npm/v/fetch-vcr.svg
[npm-url]: https://npmjs.org/package/fetch-vcr
[downloads-image]: http://img.shields.io/npm/dm/fetch-vcr.svg
[downloads-url]: https://npmjs.org/package/fetch-vcr
[travis-image]: https://img.shields.io/travis/philschatz/fetch-vcr.svg
[travis-url]: https://travis-ci.org/philschatz/fetch-vcr
[dependency-image]: https://img.shields.io/david/philschatz/fetch-vcr.svg
[dependency-url]: https://david-dm.org/philschatz/fetch-vcr
[dev-dependency-image]: https://img.shields.io/david/dev/philschatz/fetch-vcr.svg
[dev-dependency-url]: https://david-dm.org/philschatz/fetch-vcr#info=devDependencies
[coverage-image]: https://img.shields.io/codecov/c/github/philschatz/fetch-vcr.svg
[coverage-url]: https://codecov.io/gh/philschatz/fetch-vcr