136 lines
3.3 KiB
Markdown
136 lines
3.3 KiB
Markdown
# 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'
|
|
}
|
|
```
|