mocha-chai-snapshot

Hook for chai to generate and matche snapshot in testing node application just like in jest

Getting Started

Install mocha-chai-snapshot using npm:

``bash
npm install --save-dev mocha-chai-snapshot
`

Example Useage
`javascript
// first.spec.js => The first file test-runner executes or add these below lines at the top of every spec file
const chai = require('chai');
const chaiSnapshot = require('mocha-chai-snapshot');
const { expect } = chai;
chai.use(chaiSnapshot);


//component.spec.js
describe("GET /hello", () =>{
it("Should say Hello to Starnger", () => {
return request(app)
.get('/hello')
.set('Accept', 'application/json')
.expect('Content-Type', /json/)
.expect(200)
.then(({ body }) => {
expect(body).to.matchSnapshot(this);
});
});

it("Should say Hello to Jhon", () => {
return request(app)
.get('/hello')
.query({ name: 'Jhon' })
.set('Accept', 'application/json')
.expect('Content-Type', /json/)
.expect(200)
.then(({ body }) => {
expect(body).to.matchSnapshot(this);
});
});
});
`
It will automatically create(if CHAI_SNAPSHOT_UPDATE environment variable to true) __snapshots__ folder in same folder of specs and snapshot file like below
`javascript
exports[GET /hello : Should say Hello to Starnger 1] = "Hello, stranger!";
exports[GET /hello : Should say Hello to Jhon 1] = {
"name": "Jhon",
"say": "Hello"
};
`

If the found snapshot does not match with the actuals and you want to update the related snapshots, use isForced in expect chain.

Example Useage
`javascript
// first.spec.js => The first file testrunner executes or add these below lines at the top of every spec file
const chaiSnapshot =require('mocha-chai-snapshot');

chai.use(chaiSnapshot);


//component.spec.js
it("Should say Hello", () => {
return request(app)
.get('/hello')
.query({ name: 'Jack' })
.set('Accept', 'application/json')
.expect('Content-Type', /json/)
.expect(200)
.then(({ body }) => {
expect(body).isForced.to.matchSnapshot(this);
});
});
`

Or

Set CHAI_SNAPSHOT_UPDATE = true to update the snapshots if there is any mismatch in any of the spec files even if isForced is not used.

Warning!: Do not set CHAI_SNAPSHOT_UPDATE = true in build pipeline. If it is set, build will never fail even if there is no snapshots available in the __snapshots__ folder.

Notes: It is tested in mocha v5.2.0 and chai v4.2.0`.