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diff --git a/node_modules/undici/docs/best-practices/mocking-request.md b/node_modules/undici/docs/best-practices/mocking-request.md new file mode 100644 index 0000000..6954392 --- /dev/null +++ b/node_modules/undici/docs/best-practices/mocking-request.md @@ -0,0 +1,136 @@ +# Mocking Request + +Undici has its own mocking [utility](../api/MockAgent.md). It allow us to intercept undici HTTP requests and return mocked values instead. It can be useful for testing purposes. + +Example: + +```js +// bank.mjs +import { request } from 'undici' + +export async function bankTransfer(recipient, amount) { + const { body } = await request('http://localhost:3000/bank-transfer', + { + method: 'POST', + headers: { + 'X-TOKEN-SECRET': 'SuperSecretToken', + }, + body: JSON.stringify({ + recipient, + amount + }) + } + ) + return await body.json() +} +``` + +And this is what the test file looks like: + +```js +// index.test.mjs +import { strict as assert } from 'assert' +import { MockAgent, setGlobalDispatcher, } from 'undici' +import { bankTransfer } from './bank.mjs' + +const mockAgent = new MockAgent(); + +setGlobalDispatcher(mockAgent); + +// Provide the base url to the request +const mockPool = mockAgent.get('http://localhost:3000'); + +// intercept the request +mockPool.intercept({ + path: '/bank-transfer', + method: 'POST', + headers: { + 'X-TOKEN-SECRET': 'SuperSecretToken', + }, + body: JSON.stringify({ + recipient: '1234567890', + amount: '100' + }) +}).reply(200, { + message: 'transaction processed' +}) + +const success = await bankTransfer('1234567890', '100') + +assert.deepEqual(success, { message: 'transaction processed' }) + +// if you dont want to check whether the body or the headers contain the same value +// just remove it from interceptor +mockPool.intercept({ + path: '/bank-transfer', + method: 'POST', +}).reply(400, { + message: 'bank account not found' +}) + +const badRequest = await bankTransfer('1234567890', '100') + +assert.deepEqual(badRequest, { message: 'bank account not found' }) +``` + +Explore other MockAgent functionality [here](../api/MockAgent.md) + +## Debug Mock Value + +When the interceptor and the request options are not the same, undici will automatically make a real HTTP request. To prevent real requests from being made, use `mockAgent.disableNetConnect()`: + +```js +const mockAgent = new MockAgent(); + +setGlobalDispatcher(mockAgent); +mockAgent.disableNetConnect() + +// Provide the base url to the request +const mockPool = mockAgent.get('http://localhost:3000'); + +mockPool.intercept({ + path: '/bank-transfer', + method: 'POST', +}).reply(200, { + message: 'transaction processed' +}) + +const badRequest = await bankTransfer('1234567890', '100') +// Will throw an error +// MockNotMatchedError: Mock dispatch not matched for path '/bank-transfer': +// subsequent request to origin http://localhost:3000 was not allowed (net.connect disabled) +``` + +## Reply with data based on request + +If the mocked response needs to be dynamically derived from the request parameters, you can provide a function instead of an object to `reply`: + +```js +mockPool.intercept({ + path: '/bank-transfer', + method: 'POST', + headers: { + 'X-TOKEN-SECRET': 'SuperSecretToken', + }, + body: JSON.stringify({ + recipient: '1234567890', + amount: '100' + }) +}).reply(200, (opts) => { + // do something with opts + + return { message: 'transaction processed' } +}) +``` + +in this case opts will be + +``` +{ + method: 'POST', + headers: { 'X-TOKEN-SECRET': 'SuperSecretToken' }, + body: '{"recipient":"1234567890","amount":"100"}', + origin: 'http://localhost:3000', + path: '/bank-transfer' +} +``` |