core-mock-api

Welcome to core-mock-api 👋

Base Mock API for developers to be able to test REST services

🏠 Homepage

Prerequisites

• node >=18 <19

Install

yarn install

Run linting

yarn lint

Run tests

yarn test

Run typechecks

yarn tsc

Usage

Development

yarn dev

app accessible at localhost:8080

We are based on JSON Server, https://github.com/typicode/json-server

Data and server config is stored in src/db.json. If you make POST, PUT, PATCH or DELETE requests, changes will be automatically and safely saved to db.json using lowdb.

Id values are not mutable. Any id value in the body of your PUT or PATCH request will be ignored. Only a value set in a POST request will be respected, but only if not already taken.

Server supports these HTTP Methods:

GET    /posts
GET    /posts/1
POST   /posts
PUT    /posts/1
PATCH  /posts/1
DELETE /posts/1

Filter

Use . to access deep properties

GET /posts?title=json-server&author=typicode
GET /posts?id=1&id=2
GET /comments?author.name=typicode

Paginate

Use _page and optionally _limit to paginate returned data.

In the Link header you'll get first, prev, next and last links.

GET /posts?_page=7
GET /posts?_page=7&_limit=20

10 items are returned by default

Sort

Add _sort and _order (ascending order by default)

GET /posts?_sort=views&_order=asc
GET /posts/1/comments?_sort=votes&_order=asc

For multiple fields, use the following format:

GET /posts?_sort=user,views&_order=desc,asc

Data generation

yarn generate:data

will generate data to src/db.json from config.json. Config definition looks like this:

{
  ...
  "<endpoint>": {
    "config": {
      // config of properties returnd and managed by endpoint
      "<property_name>": type
    },
    "size": number,
    "data": [
      // you can pass specific data based on endpoint config
    ]
  }
}

• config
  • config of properties returnd and managed by endpoint
  • supported types:
    • "id" - default identificator
    • we support Faker https://fakerjs.dev/ so any API options is valid to pass, eg "commerce.product"
• size - size of generated collection, by default 10
• data - you can pass specific data based on endpoint config, data are merged with generated data

example:

{
  ...
  "products": {
    "config": {
      "id": "id",
      "title": "commerce.product",
      "description": "commerce.productDescription",
    },
    "size": 100,
    "data": [
      { "id": 1, "title": "Product number 1", "description": "Some description" },
      { "id": 2, "title": "Product number 2", "description": "Some description" },
      { "id": 3, "title": "Product number 3", "description": "Some description" }
    ]
  },
  ...
}

Nested routing

JSON Server automatically resolves nested routing when proper id and parent id <endpoint>Id are provided.

"comments": {
    "config": {
      "id": "id",
      "postId": "relation.posts.id",
    },
  }

postId has

Advanced endpoint mocking

JSON Server does not support composed routes so you could MOCK these by use of customRouter.ts or by configuring your own router.

import express from 'express';

const router = express.Router();

router.use('/api/admin/about', (req, res) => {
  res.json({ 
    message: 'example of composed routes which could not be handled by JSON server'
  });
});

export const customRouter = router;

Advanced endpoint with custom statuses and errors

when in need to test specific statuses mainly for error handling, those can be added to config under specific section __errors__

{
  "posts": {
    "data": [
      { "id": 1, "title": "Post number 1", "description": "Some description" },
      { "id": 2, "title": "Post number 2", "description": "Some description" },
      { "id": 3, "title": "Post number 3", "description": "Some description" },
      { "id": 4, "title": "Post number 4", "description": "Some description" },
      { "id": 5, "title": "Post number 5", "description": "Some description" }
    ]
  },
  ...
  "__errors__": {
    "validate": {
      "status": 400,
      "error": {
        "message": "Validation failed"
      }
    },
    "custom": {
      "status": 403,
      "method": "post",
      "error": {
        "message": "Custom Forbidden"
      }
    }
  }
}

Production build

yarn build

Production run

yarn start

app accessible at localhost:8080

CLI use (nodejs binary)

example running API server in apiMocks folder and config in configError1.json

➜  apiMocks npx @e1011/mock-api@latest ./configError1.json
Need to install the following packages:
  @e1011/mock-api@0.0.24
Ok to proceed? (y) y


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Mock API server, v0.0.24

Mock Api Lib is Installed
Mock API express app running at 8080

Static server

npx @e1011/mock-api@latest ./configError1.json ./folderWithStaticFiles

Custom port

pass as 3rd argument, will affect both api and static, so that localhost:[port]/api serves all endpoints from config, and localhost:[port]/static serves the static folder

npx @e1011/mock-api@latest ./configError1.json ./folderWithStaticFiles 4200

Docker use

build

yarn docker:build

run

yarn docker:run

app accessible at localhost:8080