Easy Mocking for AWS SDK v3
npm install @juit/lib-aws-mockA simple way to create mocks for the AWS SDK v3 library.
* Mocking commands
* Call Tracing
* State for Handlers
* Resetting
* Destroying
* Typical Test Scenario
* License
* Copyright Notice
Mocking commands for an AWS client is quite easy. For example:
``typescript
import { AWSMock } from '@juit/lib-aws-mock'
import {
AssumeRoleCommand,
GetCallerIdentityCommand,
STS,
} from '@aws-sdk/client-sts'
const mock = new AWSMock(STS)
.on(GetCallerIdentityCommand, (input, state) => {
// here input will be the parameter passed to getCallerIdentity(...)state
// and will be whatever was passed to mock.setState(...)
return { Account: 'the account' }
})
.on(AssumeRoleCommand, (input, state) => {
// ... mocked implementation lives here...
})
const sts = new STS({})
const identity = await sts.getCallerIdentity({})
// here identity will be { Account: 'the account' }`
// as returned by our handler configured in the mock
Instances of AWSMock provide a getCalls() function returning
all calls invoked on the mock. Calls will contain the following:
* command: The _string_ name of the command invokedinput
* : The input given to the callsuccess
* : A _boolean_ indicating whether the call succeeded or not
`typescript
const identity = await sts.getCallerIdentity({})
const calls = mock.calls()
// here calls will be:`
// {
// command: 'GetCallerIdentityCommand',
// input: '',
// success: true,
// }
Instances of AWSMock provide a setState(...) function which can be used
to pass extra data to handlers:
`typescriptstring
const mock = new AWSMock
.on(GetCallerIdentityCommand, (input, state) => {
// state will have a type
return { Account: state || 'the account' }
})
const sts = new STS({})
const identity1 = await sts.getCallerIdentity({})
// here identity1 will be { Account: 'the account' }
mock.setState('another account') // set the stae
const identity2 = await sts.getCallerIdentity({})
// here identity2 will be { Account: 'another account' }`
Reseting calls and state is as easy as
calling the reset() function on the mock instance.
Destroying the mock instance and un-hooking it from the client can be done
calling the destroy() function on the mock instance.
A typical test scenario can look somehow like this:
`typescript
describe('My Suite', () => {
let mock: AWSMock
beforeAll(() => {
mock = new AWSMock(STS)
.on(GetCallerIdentityCommand, (input, state) => {
// ... mocked implementation lives here...
})
.on(AssumeRoleCommand, (input, state) => {
// ... mocked implementation lives here...
})
})
afterAll(() => mock.destroy())
afterEach(() => mock.reset())
it('should run this spec', async () => {
// ... here's your spec...
})
})
``