Hook for chai to generate and matche snapshot in testing node application just like in jest
Install mocha-chai-snapshot using npm
:
npm install --save-dev mocha-chai-snapshot
Example Useage
// 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
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
// 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
.