how to use sinon to test two await in a line - mocha.js

I want to stub some codes that have two await in line.
import { githubApi } from "../../githubApi";
export async function getMembers (projectName) {
const members = await (await githubApi(projectName)).projects
.members({
id: 'xxx'
});
return members;
}
how can I use sinon to mock await (await githubApi(projectName)).projects
.member ? thanks

Although the API in the example seems difficult to test I will assume that has been taken into account and that githubApi is in some why mock-able.
let membersFake = sinon.fake().resolves([member1, member2, member3]);
let githubApiFake = sinon.fake().resolves({
projects: {
members: membersFake
}
});
Then you can replace the githubApi with the fake. Now if githubApi is not easily mock-able and you don't own that file maybe it is worth looking into some dependency injection.
export async function getMembers (projectName, githubApi = githubApi) {
...
}
In this way you can pass in your fake directly when testing the function in a unit test but in your app code it will default to the real one imported.

Related

How to use enhancers (pipes, guards, interceptors, etc) with Nestjs Standalone app

The Nestjs module system is great, but I'm struggling to figure out how to take full advantage of it in a Serverless setting.
I like the approach of writing my domain logic in *.service.ts files, while using *.controller.ts files to take care of non-business related tasks such as validating an HTTP request body and converting to a DTO before invoking methods in a service.
I found the section on Serverless in the nestjs docs and determined that for my specific use-case, I need to use the "standalone application feature".
I created a sample nestjs app here to illustrate my problem.
The sample app has a simple add() function to add two numbers. I use class-validator for validation on the AddDto class.
// add.dto.ts
import { IsNumber } from 'class-validator'
export class AddDto {
#IsNumber()
public a: number;
#IsNumber()
public b: number;
}
And then, via some Nestjs magic, I am able to get built-in validation using the AddDto inside my controller by doing the following:
// main.ts
async function bootstrap() {
const app = await NestFactory.create(AppModule);
// Use `ValidationPipe()` for auto-validation in controllers
app.useGlobalPipes(
new ValidationPipe({ transform: true })
)
await app.listen(3000);
}
// app.controller.ts
#Controller()
export class AppController {
constructor(private readonly appService: AppService) {}
#Post('add')
add(#Body() dto: AddDto): number {
// Request body gets auto validated and converted
// to an instance of `AddDto`, sweet!
return this.appService.add(dto.a, dto.b);
}
}
// app.service.ts
#Injectable()
export class AppService {
add(a: number, b: number): number {
return a + b
}
}
So far, so good. The problem now arises when using this in AWS with a Lambda function, namely:
I want to re-use the business logic in app.service.ts
I want to re-use built in validation that happens when making an HTTP request to the app, such as in the example above.
I want to use the standalone app feature so I don't have to spin up an entire nest server in Lambda
The docs hint on this being a problem:
Be aware that NestFactory.createApplicationContext does not wrap controller methods with enhancers (guard, interceptors, etc.). For this, you must use the NestFactory.create method.
For example, I have a lambda that receives messages from AWS EventBridge. Here's a snippet from the sample app:
// standalone-app.ts
interface IAddCommand {
a: number;
b: number;
}
export const handler = async (
event: EventBridgeEvent<'AddCommand', IAddCommand>,
context: any
) => {
const appContext = await NestFactory.createApplicationContext(AppModule);
const appService = appContext.get(AppService);
const { a, b } = event.detail;
const sum = appService.add(a, b)
// do work on `sum`, like cache the result, etc...
return sum
};
// lambda-handler.js
const { handler } = require('./dist/standalone-app')
handler({
detail: {
a: "1", // is a string, should be a number
b: "2" // is a string, should be a number
}
})
.then(console.log) // <--- prints out "12" ("1" + "2") instead of "3" (1 + 2)
I don't get "free" validation of the event's payload in event.detail like I do with #Body() dto: AddDto when making a HTTP POST request to /add. Preferentially, the code would throw a validation error in the above example. Instead, I get an answer of "12" -- a false positive.
Hopefully, this illustrates the crux of my problem. I still want to validate the payload of the event before calling appService.add(a, b), but I don't want to write custom validation logic that already exists on the controller in app.controller.ts.
Ideas? Anyone else run into this before?
It occurred to me while writing this behemoth of a question that I can simply use class-validator and class-transformer in my Lambda handler.
import { validateOrReject } from 'class-validator'
import { plainToClass } from 'class-transformer'
import { AddDto } from 'src/dto/add.dto'
export const handler = async (event: any, context: any) => {
const appContext = await NestFactory.createApplicationContext(AppModule);
const appService = appContext.get(AppService);
const data = getPayloadFromEvent(event)
// Convert raw data to a DTO
const dto: AddDto = plainToClass(AddDto, data)
// Validate it!
await validateOrReject(dto)
const sum = appService.add(dto.a, dto.b)
// do work on `sum`...
}
It's not as "free" as using app.useGlobalPipes(new ValidationPipe()), but only involves a few extra lines of code.
It worked for me with the following lambda file for nestjs.
import { configure as serverlessExpress } from '#vendia/serverless-express';
import { NestFactory } from '#nestjs/core';
import { AppModule } from './app.module';
import { ValidationPipe } from '#nestjs/common';
let cachedServer;
export const handler = async (event, context) => {
if (!cachedServer) {
const nestApp = await NestFactory.create(AppModule);
await nestApp.useGlobalPipes(new ValidationPipe());
await nestApp.init();
cachedServer = serverlessExpress({
app: nestApp.getHttpAdapter().getInstance(),
});
}
return cachedServer(event, context);
};

Is that possible to assign a type to this (cucumber world object)

Is that possible to have the completion with this world object ?
I mean...
I have a class named Application
export class Application {
constructor() {}
async run() {
// do stuff to run the app
}
get applicationDescription(): string {
return 'The best application in the world';
}
}
In my step
Given('I run my application', {timeout: 10000}, async function() {
this.app: Application = new Application();
await this.app.run(); <-- here when I write this.app. I want to see that run is a
accessible method
});
In the most basic sense, this is world within a step definition (you must NOT use arrow functions, as you have shown):
Given('I run my application', {timeout: 10000}, async function() {
this.app = new Application();
await this.app.run();
});
When done in this fashion you are just monkey patching properties onto the world object, so its working on the basis that its type is any, so you don't get type safety/autocomplete in your IDE.
You can use a custom world to get those benefits:
class MyWorld extends World {
app: Application
constructor(props: IWorldOptions) {
super(props)
}
}
setWorldConstructor(MyWorld)
Given('I run my application', this: MyWorld, {timeout: 10000}, async function() {
this.app = new Application();
await this.app.run();
});
Note that the second param is this: MyWorld, which is allowed in typescript to provide a type override for the this. It must come before any other params. If you omit it, this is still typed as Cucumbers World so you're back to any.

TypeGraphQl: Usage with Netlify Functions/AWS Lambda

I was finally able to get TypeQL working with Netlify Functions / AWS Lambda after a day of work, going over the docs and examples, and in the end desperate brute force.
I'm sharing my working code here for others (or for future reference of my own :P ) as it contains some counterintuitive keyword usage.
Normal Approach
The error I kept getting when using the simple example was:
Your function response must have a numerical statusCode. You gave: $ undefined
I searched of course in the issues, but none of the suggested solutions worked for me.
Working Code
import 'reflect-metadata'
import { buildSchema } from 'type-graphql'
import { ApolloServer } from 'apollo-server-lambda'
import { RecipeResolver } from 'recipe-resolver'
async function lambdaFunction() {
const schema = await buildSchema({
resolvers: [RecipeResolver],
})
const server = new ApolloServer({
schema,
playground: true,
})
// !!! NOTE: return (await ) server.createHandler() won't work !
exports.handler = server.createHandler()
}
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
// !!! NOTE: weird but only way to make it work with
// AWS lambda and netlify functions (netlify dev)
// also needs a reload of the page (first load of playground won't work)
lambdaFunction()
// exports.handler = lambdaFunction wont work
// export { lambdaFunction as handler } wont work
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Also I got some reflection errors from the simple example
Unable to infer GraphQL type from TypeScript reflection system. You need to provide explicit type for argument named 'title' of 'recipe' of 'RecipeResolver
So I had to figure out how to add explicit type to #Arg:
// previous:
// recipe(#Arg('title') title: string)
// fixed:
recipe( #Arg('title', (type) => String) title: string
I share the code that works for me
// File: graphql.ts
import 'reflect-metadata'
import { buildSchema } from 'type-graphql'
import { ApolloServer } from 'apollo-server-lambda'
import { ApolloServerPluginLandingPageGraphQLPlayground } from 'apollo-server-core'
import { RecipeResolver } from './recipe-resolver'
export const createHandler = async function(){
const schema = await buildSchema({
resolvers: [RecipeResolver],
})
const server = new ApolloServer({
schema,
introspection: true,
plugins: [ApolloServerPluginLandingPageGraphQLPlayground()],
})
return server.createHandler()
}
export const handler = async function(event, context, callback) {
const graphqlHandler = await createHandler()
return await graphqlHandler(event, context, callback)
}
// Lambda: graphql.handler
node16.x
type-graphql ^1.1.1
graphql ^15.3.0
apollo-server-lambda: ^3.10.2

How can I spyOn `useMutation` so that I can see what the values are being passed?

Rather than create a massive E2E test, I want to verify what the useMutation is receiving from the component. There is a lot of business logic before my component "posts" and I want to test that the GraphQL mutation function is receiving the shape of data.
Manually mocking the query doesn't provide value in this case, as it skips the business logic I want to keep track of. There is no value right now to let the query return full data & response, as my component will unmount and URL will change after successful data is returned.
So ideally, we just stop the test when the useMutation hook is called.
I am hoping to do something like:
const mutationSpy = jest.spyOn(graphQL, 'useMutation');
...
expect(mutationSpy).toHaveBeenCalledWith(myDataShape);
The best way to track whether a mutation has been called is to use the MockedProvider from #apollo/react-testing (react-native) or #apollo/client (react) to supply a callback function to your mock response that changes a variable in the test scope so that it may be checked once the test has been run. Something like this.
Here is the documentation:
https://www.apollographql.com/docs/react/development-testing/testing/#testing-mutation-components
test.js
let createMutationCalled = false
const mocks = [
{
request,
result: () => {
createMutationCalled = true
return { data }
}
}
];
describe('test', () => {
test('should call createTicket mutation', async () => {
const { getByTestId } = render(
<MockedProvider mocks={mocks}>
<SelfReportPage />
</MockedProvider>
)
let input = getByTestId('sr-description')
let submit = getByTestId('sr-submit')
fireEvent.changeText(input, 'Test text.')
fireEvent.press(submit)
await new Promise(r => setTimeout(r, 0));
expect(createMutationCalled).toBe(true)
})
})

Testing an Async function using Jest / Enzyme

Trying run a test case for the following:
async getParents() {
const { user, services, FirmId } = this.props;
let types = await Models.getAccounts({ user, services, firmId: FirmId });
let temp = types.map((type) => {
if(this.state.Parent_UID && this.state.Parent_UID.value === type.Account_UID) {
this.setState({Parent_UID: {label: type.AccountName, value: type.Account_UID}})
}
return {
label: type.AccountName,
value: type.Account_UID,
}
})
this.setState({ParentOptions: temp});
}
here is what i have so far for my test:
beforeEach(() => wrapper = mount(<MemoryRouter keyLength={0}><AccountForm {...baseProps} /></MemoryRouter>));
it('Test getParents function ',async() => {
wrapper.setProps({
user:{},
services:[],
FirmId:{},
})
wrapper.find('AccountForm').setState({
SourceOptions:[[]],
Parent_UID: [{
label:[],
value:[],
}],
});
wrapper.update();
await
expect(wrapper.find('AccountForm').instance().getParents()).toBeDefined()
});
If i try to make this ToEqual() it expects a promise and not anobject, what else could I add into this test to work properly.
Goal: Make sure the functions gets called correctly. The test is passing at the moment and has a slight increase on test coverage.
Using Jest and Enzyme for React Js
you can put the await before the async method, like:
await wrapper.find('AccountForm').instance().getParents()
and compare if the state was changed.
In another way, if can mock your API request, because this is a test, then you do not need the correct API, but know if the function calls the API correctly and if the return handling is correct.
And, you cand spy the function like:
const spy = jest.spyOn(wrapper.find('AccountForm').instance(), 'getParents');
and campare if the function was called if they are triggered by some action:
expect(spy).toBeCalled()

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