eslint-plugin-should-promised

eslint-plugin-should-promised

Eslint rule for checking that should-promised assertions return

Install

$ npm i -D eslint-plugin-should-promised

Configure

{
  "plugins": [
    "should-promised"
  ],
  "rules": {
    "should-promised/return-promise": 2
  }
}

Rules

Require promise assertions to return (return-promise)

This rule is intended to be used with the should-promised plugin for the should assertion library.

When testing an async function by returning a promise to mocha it is important to remember to actually return the promise. Forgetting to return will not cause the test case to fail.

This rule will point out when a should-promised assertion is made without returning.

Rule Details

This rule looks for any of the properties Promise, fulfilled, fulfilledWith, rejected, rejectedWith, finally and eventually.

The following patterns are considered warnings:

describe('forgot to return the promise', function() {
  it('warn when not returning the promise from should.be.fulfilled', function() {
    thing.fn().should.be.fulfilled();
  });

  it('warn when not returning the promise from should.eventually', function() {
    thing.fn().should.eventually.eql(1);
  });
});

These patterns would not be considered warnings:

describe('forgot to return the promise', function() {
  it('warn when not returning the promise from should.be.fulfilled', function() {
    return thing.fn().should.be.fulfilled();
  });

  it('warn when not returning the promise from should.eventually', function() {
    return thing.fn().should.eventually.eql(1);
  });
});

Further Reading

• The should assertion library
• The should-promised plugin