grumpus v0.0.1-dev

Grumpus

It gets upset if your API data is bad!

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Purpose

Testing an API can be an arduous task. You have to check to make sure the API returns the correct data in the correct format, but you tend to do all this work of checking without ever being able to use those same structures to produce Typescript types or generate test data. This small library acts like a helpful bridge between io-ts and your API. It allows you to assert that the response from an HTTP call matches the schema provided.

Installation

npm i grumpus --save

Basic Usage

This library simply checks an endpoint using the io-ts schema you expect the endpoint to return. Your schema can be an application dependency if you use your schema at runtime to produce guards, decoders, JSONEncoders, etc. If you only want to use your schema for testing and generating test data, you can keep them separate from your runtime source. Once you have your schema, you can use the checkEndpoint function to test an endpoint with a schema.

import * as RTE from 'fp-ts/lib/ReaderTaskEither'
import * as E from 'fp-ts/lib/Either'
import {make, TypeOf} from 'io-ts/lib/Schema'
import {CheckEndpointDeps, checkEndpoint} from 'grumpus' 

const articleSchema = make(s => s.type({ id: s.number, content: s.string }))
type Article = TypeOf<typeof articleSchema>

const testData: CheckEndpointDeps<Article> = {
  url: 'https://www.yourcoolwebsite.com/api/articles/1',
  expectations: {
    schema: articleSchema,
    status: 200
  }
}

describe('The articles endpoint', () => {
  it('returns a valid Article', () =>{

    // Your data's structure is checked automatically
    RTE.run(checkEndpoint, testData).then(e => {
      E.either.map(e, r => {
        // Additional assertions go here
        expect(r.statusText).toBe('OK')
      })
    })
  })
})