Merge pull request #524 from wheresrhys/cheatsheet

Cheatsheet

docs/cheatsheet.md

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+# fetch-mock cheatsheet
+
+*This is a first draft - please feedback in the [issues](https://github.com/wheresrhys/fetch-mock/issues)*
+
+- [Installation](#installation)
+- [Set up and teardown](#setup-and-teardown)
+- [Request matching](#request-matching)
+- [Response configuration](#response-configuration)
+- [Inspecting calls](#inspecting-calls)
+
+## Installation
+
+`npm i -D fetch-mock` (or `npm i -D fetch-mock-jest` if using jest)
+
+### Global fetch
+import/require the fetch-mock/fetch-mock-jest library. For the vast majority of test toolchains this _should_ jsut work without any additional wiring.
+
+### Local fetch with jest
+```js
+jest.mock('node-fetch', () => require('fetch-mock-jest').sandbox())
+const fetchMock = require('node-fetch')
+```
+
+### Local fetch with other test runners
+```js
+// pass this mock into your module mocking tool of choice
+// Example uses https://www.npmjs.com/package/proxyquire
+const fetchMock = require('fetch-mock').sandbox()
+proxyquire('./my-module', {'node-fetch': fetchMock})
+```
+
+## Setup and teardown
+
+### Mock setup methods
+All these methods can be chained e.g. `fetchMock.getAny(200).catch(400)`
+- Stub fetch and **define a route** `.mock(matcher, response)`
+- Stub fetch **without a route** `.mock()`
+- Spy on calls, letting them **fall through to the network** `.spy()`
+- Respond with the given response to any **unmatched calls** `.catch(response)`
+- Add a mock that only responds **once** `.once(matcher, response)`
+- Add a mock that responds to **any** request `.any(response)`
+- Add a mock that responds to **any request, but only once** `.anyOnce(response)`
+- Add a mock that only responds to the given **method** `.get()`, `.post()`, `.put()`, `.delete()`, `.head()`, `.patch()`
+- **Combinations** of the above behaviours `getAny()`, `getOnce()`, `getAnyOnce()`, `postAny()` ...
+
+### Tear down methods
+- Remove all mocks and history `.restore()`, `.reset()`
+- Discard all recorded calls, but keep defined routes `.resetHistory()`
+- Discard all routes, but keep defined recorded calls`.resetBehavior()`
+
+## Request matching
+
+The following request would be matched by all the mocks described below:
+```js
+fetch('http://example.com/users/bob?q=rita', {
+    method: 'POST',
+    headers: {'Content-Type': 'application/json'},
+    body: '{"prop1": "val1", "prop2": "val2"}'
+})
+```
+
+### Urls
+Can be passed as
+- the first argument `.mock('blah', 200)`
+- a `url` property on the first argument `.mock({url: 'blah'}, 200)`
+
+#### Patterns
+- Match **any** url `'*'`
+- Match **exact** url `'http://example.com/users/bob?q=rita'` 
+- Match **beginning** `'begin:http://example.com'` 
+- Match **end** `'end:bob?q=rita'`
+- Match **path** `'path:/users/bob'` 
+- Match a **glob** expression `'glob:http://example.{com,gov}/*'` 
+- Match **express** syntax `'express:/users/:name'` 
+- Match a **RegExp** `/\/users\/.*/` 
+
+#### Naming routes
+When defining multiple mocks on the same underlying url (e.g. differing only on headers), set a `name` property on the matcher of each route.
+
+### Other properties
+The following should be passed as properties of the first argument of `.mock()`.
+- Match the request **method** `{method: 'POST'}`
+- Match **headers** `{headers: {'Content-Type': 'application/json'}}`
+- Match a **JSON body** `{body: {prop1: 'val1', prop2: 'val2'}}`
+- Match **part of a JSON body** `{body: {prop1: 'val1'}, matchPartialBody: true}`
+- Match **query** parameters `{query: {q: 'rita'}}`
+- Match express **path parameters** `{url: 'express:/users/:name', params: {name: 'bob'}}`
+
+### Custom
+Match on any condition you like by:
+- using a function `{functionMatcher: (url, options, request) => url.length > 100}`
+- defining your own declarative matchers with [`addMatcher()`](http://www.wheresrhys.co.uk/fetch-mock/#api-mockingadd-matcher), e.g. something like this would be possible  `{isCorsRequest: true, hasBody: true}`
+
+## Response configuration
+Responses are configured with eth second, and sometimes third, arguments passed to `.mock()` (or the first and second argument of `.any()` or `.catch()`). Where only one code sample is given below, it describes the second argument; otherwise the second and third are given. *[Note - in the next major version these will all be available on the second argument]* 
+
+- **`Response`** instance `new Response('hello world')`
+- **status code** `200`
+- **text** `hello world`
+- **JSON** `{prop: 'val'}` 
+- **streamed content** `new Blob()`, `{sendAsJson: false}`
+- **headers** `{body: 'hello world', status: 200, headers: {'Content-Type': 'text'}`
+- **throw** an error `{throws: new Error('fetch failed')}`
+- **redirect** `{redirectUrl: 'http://other.site, status: 302}`
+- **function** ``(url, options, request) => `Content from ${url}` ``
+
+### Timing and repetition
+- Respond a specified **number of times** `200`, `{repeat: 3}`
+- **Delay** by a number of milliseconds `200`, `{delay: 2000}`
+- Custom async behaviour using a **Promise** `myPromise.then(200)`
+
+Functions and Promises can be nested to any depth to implement complex race conditions
+
+## Inspecting calls
+`.calls()` retrieves a list of all calls matching certain conditions. It return an array of `[url, options]` arrays, which also have a `.request` property containng the original `Request` instance.
+
+### Filtering
+- **all** calls `.calls()`
+- **matched** calls `.calls(true)` or `.calls('matched')` 
+- **unmatched** calls `.calls(false)` or `.calls('unmatched')` 
+- calls to a **named route** `.calls('My route`)
+- calls to a **url pattern** used in a route `.calls('end:/path/bob`)
+- calls matching a **matcher** `.calls(anyValidMatcher)`
+- calls filtered by **method** `.calls(anyValidMatcher, 'POST')`
+
+### Shortcut methods
+These accept the same filters as above, but give a quicker route to answering common questions
+- Do **any calls** match the filter? `.called()`
+- What was the **last call** `.lastCall()`
+- What was the **last url** `.lastUrl()`
+- What was the **last options** `.lastOptions()`
+
+### Completion
+- Check if **all routes** have been **called as expected** `.done()`
+- Check if **all routes matching the filter** have been **called as expected** `.done(filter)` (filter must be a **route name** or **url pattern**)
+- Wait for all fetches to respond `.flush()` (pass in `true` to wait for all bodies to be streamed). e.g. `await fetchMock.flush(true)`
+
+