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diff --git a/docs/api/MockPool.md b/docs/api/MockPool.md new file mode 100644 index 0000000..96a986f --- /dev/null +++ b/docs/api/MockPool.md @@ -0,0 +1,547 @@ +# Class: MockPool + +Extends: `undici.Pool` + +A mock Pool class that implements the Pool API and is used by MockAgent to intercept real requests and return mocked responses. + +## `new MockPool(origin, [options])` + +Arguments: + +* **origin** `string` - It should only include the **protocol, hostname, and port**. +* **options** `MockPoolOptions` - It extends the `Pool` options. + +Returns: `MockPool` + +### Parameter: `MockPoolOptions` + +Extends: `PoolOptions` + +* **agent** `Agent` - the agent to associate this MockPool with. + +### Example - Basic MockPool instantiation + +We can use MockAgent to instantiate a MockPool ready to be used to intercept specified requests. It will not do anything until registered as the agent to use and any mock request are registered. + +```js +import { MockAgent } from 'undici' + +const mockAgent = new MockAgent() + +const mockPool = mockAgent.get('http://localhost:3000') +``` + +## Instance Methods + +### `MockPool.intercept(options)` + +This method defines the interception rules for matching against requests for a MockPool or MockPool. We can intercept multiple times on a single instance, but each intercept is only used once. For example if you expect to make 2 requests inside a test, you need to call `intercept()` twice. Assuming you use `disableNetConnect()` you will get `MockNotMatchedError` on the second request when you only call `intercept()` once. + +When defining interception rules, all the rules must pass for a request to be intercepted. If a request is not intercepted, a real request will be attempted. + +| Matcher type | Condition to pass | +|:------------:| -------------------------- | +| `string` | Exact match against string | +| `RegExp` | Regex must pass | +| `Function` | Function must return true | + +Arguments: + +* **options** `MockPoolInterceptOptions` - Interception options. + +Returns: `MockInterceptor` corresponding to the input options. + +### Parameter: `MockPoolInterceptOptions` + +* **path** `string | RegExp | (path: string) => boolean` - a matcher for the HTTP request path. When a `RegExp` or callback is used, it will match against the request path including all query parameters in alphabetical order. When a `string` is provided, the query parameters can be conveniently specified through the `MockPoolInterceptOptions.query` setting. +* **method** `string | RegExp | (method: string) => boolean` - (optional) - a matcher for the HTTP request method. Defaults to `GET`. +* **body** `string | RegExp | (body: string) => boolean` - (optional) - a matcher for the HTTP request body. +* **headers** `Record<string, string | RegExp | (body: string) => boolean`> - (optional) - a matcher for the HTTP request headers. To be intercepted, a request must match all defined headers. Extra headers not defined here may (or may not) be included in the request and do not affect the interception in any way. +* **query** `Record<string, any> | null` - (optional) - a matcher for the HTTP request query string params. Only applies when a `string` was provided for `MockPoolInterceptOptions.path`. + +### Return: `MockInterceptor` + +We can define the behaviour of an intercepted request with the following options. + +* **reply** `(statusCode: number, replyData: string | Buffer | object | MockInterceptor.MockResponseDataHandler, responseOptions?: MockResponseOptions) => MockScope` - define a reply for a matching request. You can define the replyData as a callback to read incoming request data. Default for `responseOptions` is `{}`. +* **reply** `(callback: MockInterceptor.MockReplyOptionsCallback) => MockScope` - define a reply for a matching request, allowing dynamic mocking of all reply options rather than just the data. +* **replyWithError** `(error: Error) => MockScope` - define an error for a matching request to throw. +* **defaultReplyHeaders** `(headers: Record<string, string>) => MockInterceptor` - define default headers to be included in subsequent replies. These are in addition to headers on a specific reply. +* **defaultReplyTrailers** `(trailers: Record<string, string>) => MockInterceptor` - define default trailers to be included in subsequent replies. These are in addition to trailers on a specific reply. +* **replyContentLength** `() => MockInterceptor` - define automatically calculated `content-length` headers to be included in subsequent replies. + +The reply data of an intercepted request may either be a string, buffer, or JavaScript object. Objects are converted to JSON while strings and buffers are sent as-is. + +By default, `reply` and `replyWithError` define the behaviour for the first matching request only. Subsequent requests will not be affected (this can be changed using the returned `MockScope`). + +### Parameter: `MockResponseOptions` + +* **headers** `Record<string, string>` - headers to be included on the mocked reply. +* **trailers** `Record<string, string>` - trailers to be included on the mocked reply. + +### Return: `MockScope` + +A `MockScope` is associated with a single `MockInterceptor`. With this, we can configure the default behaviour of a intercepted reply. + +* **delay** `(waitInMs: number) => MockScope` - delay the associated reply by a set amount in ms. +* **persist** `() => MockScope` - any matching request will always reply with the defined response indefinitely. +* **times** `(repeatTimes: number) => MockScope` - any matching request will reply with the defined response a fixed amount of times. This is overridden by **persist**. + +#### Example - Basic Mocked Request + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +// MockPool +const mockPool = mockAgent.get('http://localhost:3000') +mockPool.intercept({ path: '/foo' }).reply(200, 'foo') + +const { + statusCode, + body +} = await request('http://localhost:3000/foo') + +console.log('response received', statusCode) // response received 200 + +for await (const data of body) { + console.log('data', data.toString('utf8')) // data foo +} +``` + +#### Example - Mocked request using reply data callbacks + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/echo', + method: 'GET', + headers: { + 'User-Agent': 'undici', + Host: 'example.com' + } +}).reply(200, ({ headers }) => ({ message: headers.get('message') })) + +const { statusCode, body, headers } = await request('http://localhost:3000', { + headers: { + message: 'hello world!' + } +}) + +console.log('response received', statusCode) // response received 200 +console.log('headers', headers) // { 'content-type': 'application/json' } + +for await (const data of body) { + console.log('data', data.toString('utf8')) // { "message":"hello world!" } +} +``` + +#### Example - Mocked request using reply options callback + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/echo', + method: 'GET', + headers: { + 'User-Agent': 'undici', + Host: 'example.com' + } +}).reply(({ headers }) => ({ statusCode: 200, data: { message: headers.get('message') }}))) + +const { statusCode, body, headers } = await request('http://localhost:3000', { + headers: { + message: 'hello world!' + } +}) + +console.log('response received', statusCode) // response received 200 +console.log('headers', headers) // { 'content-type': 'application/json' } + +for await (const data of body) { + console.log('data', data.toString('utf8')) // { "message":"hello world!" } +} +``` + +#### Example - Basic Mocked requests with multiple intercepts + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo', + method: 'GET' +}).reply(200, 'foo') + +mockPool.intercept({ + path: '/hello', + method: 'GET', +}).reply(200, 'hello') + +const result1 = await request('http://localhost:3000/foo') + +console.log('response received', result1.statusCode) // response received 200 + +for await (const data of result1.body) { + console.log('data', data.toString('utf8')) // data foo +} + +const result2 = await request('http://localhost:3000/hello') + +console.log('response received', result2.statusCode) // response received 200 + +for await (const data of result2.body) { + console.log('data', data.toString('utf8')) // data hello +} +``` + +#### Example - Mocked request with query body, request headers and response headers and trailers + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo?hello=there&see=ya', + method: 'POST', + body: 'form1=data1&form2=data2', + headers: { + 'User-Agent': 'undici', + Host: 'example.com' + } +}).reply(200, { foo: 'bar' }, { + headers: { 'content-type': 'application/json' }, + trailers: { 'Content-MD5': 'test' } +}) + +const { + statusCode, + headers, + trailers, + body +} = await request('http://localhost:3000/foo?hello=there&see=ya', { + method: 'POST', + body: 'form1=data1&form2=data2', + headers: { + foo: 'bar', + 'User-Agent': 'undici', + Host: 'example.com' + } + }) + +console.log('response received', statusCode) // response received 200 +console.log('headers', headers) // { 'content-type': 'application/json' } + +for await (const data of body) { + console.log('data', data.toString('utf8')) // '{"foo":"bar"}' +} + +console.log('trailers', trailers) // { 'content-md5': 'test' } +``` + +#### Example - Mocked request using different matchers + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo', + method: /^GET$/, + body: (value) => value === 'form=data', + headers: { + 'User-Agent': 'undici', + Host: /^example.com$/ + } +}).reply(200, 'foo') + +const { + statusCode, + body +} = await request('http://localhost:3000/foo', { + method: 'GET', + body: 'form=data', + headers: { + foo: 'bar', + 'User-Agent': 'undici', + Host: 'example.com' + } +}) + +console.log('response received', statusCode) // response received 200 + +for await (const data of body) { + console.log('data', data.toString('utf8')) // data foo +} +``` + +#### Example - Mocked request with reply with a defined error + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo', + method: 'GET' +}).replyWithError(new Error('kaboom')) + +try { + await request('http://localhost:3000/foo', { + method: 'GET' + }) +} catch (error) { + console.error(error) // Error: kaboom +} +``` + +#### Example - Mocked request with defaultReplyHeaders + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo', + method: 'GET' +}).defaultReplyHeaders({ foo: 'bar' }) + .reply(200, 'foo') + +const { headers } = await request('http://localhost:3000/foo') + +console.log('headers', headers) // headers { foo: 'bar' } +``` + +#### Example - Mocked request with defaultReplyTrailers + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo', + method: 'GET' +}).defaultReplyTrailers({ foo: 'bar' }) + .reply(200, 'foo') + +const { trailers } = await request('http://localhost:3000/foo') + +console.log('trailers', trailers) // trailers { foo: 'bar' } +``` + +#### Example - Mocked request with automatic content-length calculation + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo', + method: 'GET' +}).replyContentLength().reply(200, 'foo') + +const { headers } = await request('http://localhost:3000/foo') + +console.log('headers', headers) // headers { 'content-length': '3' } +``` + +#### Example - Mocked request with automatic content-length calculation on an object + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo', + method: 'GET' +}).replyContentLength().reply(200, { foo: 'bar' }) + +const { headers } = await request('http://localhost:3000/foo') + +console.log('headers', headers) // headers { 'content-length': '13' } +``` + +#### Example - Mocked request with persist enabled + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo', + method: 'GET' +}).reply(200, 'foo').persist() + +const result1 = await request('http://localhost:3000/foo') +// Will match and return mocked data + +const result2 = await request('http://localhost:3000/foo') +// Will match and return mocked data + +// Etc +``` + +#### Example - Mocked request with times enabled + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +mockPool.intercept({ + path: '/foo', + method: 'GET' +}).reply(200, 'foo').times(2) + +const result1 = await request('http://localhost:3000/foo') +// Will match and return mocked data + +const result2 = await request('http://localhost:3000/foo') +// Will match and return mocked data + +const result3 = await request('http://localhost:3000/foo') +// Will not match and make attempt a real request +``` + +#### Example - Mocked request with path callback + +```js +import { MockAgent, setGlobalDispatcher, request } from 'undici' +import querystring from 'querystring' + +const mockAgent = new MockAgent() +setGlobalDispatcher(mockAgent) + +const mockPool = mockAgent.get('http://localhost:3000') + +const matchPath = requestPath => { + const [pathname, search] = requestPath.split('?') + const requestQuery = querystring.parse(search) + + if (!pathname.startsWith('/foo')) { + return false + } + + if (!Object.keys(requestQuery).includes('foo') || requestQuery.foo !== 'bar') { + return false + } + + return true +} + +mockPool.intercept({ + path: matchPath, + method: 'GET' +}).reply(200, 'foo') + +const result = await request('http://localhost:3000/foo?foo=bar') +// Will match and return mocked data +``` + +### `MockPool.close()` + +Closes the mock pool and de-registers from associated MockAgent. + +Returns: `Promise<void>` + +#### Example - clean up after tests are complete + +```js +import { MockAgent } from 'undici' + +const mockAgent = new MockAgent() +const mockPool = mockAgent.get('http://localhost:3000') + +await mockPool.close() +``` + +### `MockPool.dispatch(options, handlers)` + +Implements [`Dispatcher.dispatch(options, handlers)`](Dispatcher.md#dispatcherdispatchoptions-handler). + +### `MockPool.request(options[, callback])` + +See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback). + +#### Example - MockPool request + +```js +import { MockAgent } from 'undici' + +const mockAgent = new MockAgent() + +const mockPool = mockAgent.get('http://localhost:3000') +mockPool.intercept({ + path: '/foo', + method: 'GET', +}).reply(200, 'foo') + +const { + statusCode, + body +} = await mockPool.request({ + origin: 'http://localhost:3000', + path: '/foo', + method: 'GET' +}) + +console.log('response received', statusCode) // response received 200 + +for await (const data of body) { + console.log('data', data.toString('utf8')) // data foo +} +``` |