express-middleware-mock

Middleware to mock requests using jsons and semantic folders on express

Installation

``
npm i express-middleware-mock
`

Usage

`
import express, { Request, Response, NextFunction } from "express";
import cors from "cors"; //optional
import mockJson from "express-middleware-mock";

const USE_MOCK = process.env.USE_MOCK || false;
const MOCK_FOLDER = process.env.MOCK_FOLDER || './jsons';

const app = express();
app.use(cors());
app.use(express.json());

//here your router
const router = express.Router();
router.get(
"/my/router/example",
async (req: Request, res: Response) => {
res.status(200).send({
success: true,
messages: ["ok"]
})
}
);

if (USE_MOCK) {
//if enter here
app.use(mockJson(MOCK_FOLDER));
}

`

Creating Requests and Responses

To create requests and responses you need to create a folder with semantic name as a request path, and put two files request.json and response.json inside OR you can create just a single file named redirect.json

$3

Request file simbolise what do you need to receive as query params, body or parameter, and the syntax need to be:

`
{
"params": {
"someValueFromQueryParams": true
},
"headers":{
"someHeadersParamsHere": true,
"bearer": true
},
"body":{
"myPostParamHere": true
},
"query":{
"myQueryParamHere": true
}
}
`

- body: for params inside a body request (not work for GET methods)
- query: for params on url, after ? simble, like ?skip=0
- params: it is not possible to check url params yet
- headers: Set required variables from headers

Examples:

To recieve userId and userEmail on post method

`
{
"body": {
"userId": true,
"userEmail": true
}
}
`

To recieve skip and limit on get method as url params, but not optionaly, and category need to be setted

`
{
"query": {
"skip": false,
"limit": false,
"category": true
}
}
`

`
{
"headers": {
"bearer": true
}
}
`

$3

Just need to be a valid json file and they will be used in body result.

The middleware will be put automatic properties to indentify this result as a fake result

`
{
isRedirected: true,
fakeResult: true
}
`

And if you put some values that exists on faker as a method or inside a objectHandler as a methodName, the value will be put with a method result.

You also can create a response using a list response pattern like this:

| tip: If you use this struture to result list, the fake result layer will simulate a list of result

`
{
"total": 405,
"skiped": 0,
"limited": 10,
"list": [
{
"id": "uuid",
"name": "name.fullName",
"description": "lorem",
"otherThing": "{query.skip}"
}
]
}
`

And they will be simulate 405 results on database to create a pagination system. Notice that you just need to put 1 object inside an array and they will use this as a pattern to create others.

You can response asingle result:

`
{
"id": "uuid",
"category": "that|this|other"
}
`

| tips: if you put pipe | to split string, they will random someone to result

$3

You can create your own result handler

`
const myHandler = {
mySecret:()=>{
return "my secret word here"
}
}

if (USE_MOCK) {
//using your own handler
app.use(mockJson(MOCK_FOLDER, myHandler));
}
`

| tip: Use relative path with ./ or absolute path

And now you can use:

`
{
"category": "that|this|other",
"test" : "mySecret"
}
`

The result will be:

`
{
"category": "other",
"test" : "my secret word here"
}
`

$3

`
.
/mock
/test
/a
request.json
response.json
/my
/router
/example
request.json
response.json
/example-2
request.json
response.json
errors.json
/other
/[paramName] <- this variable goes to params variable as paramName
/test
/api
/users
/list
redirect.json
`

We have 3 examples here and all of them inside a 'jsons' folder.

- test/a using request/response files
- my/router/example using request/response files BUT using a existed router path
- my/router/example-2 using request/response and chance to result error
- api/users/list` using redirect.json file