pdf-controller.test.js

const chai = require('chai');
chai.use(require('sinon-chai'));

const sinon = require('sinon');

describe('controller.Pdfs', () => {
  var bottle, generate, res;
  
  beforeEach(() => {
    res = {
      json: sinon.spy()
    };
    
    bottle = new Bottle();
    // Load the subject under test into the unit container.
    // Note the path here relative is to NODE_PATH, which we've set to the root of the project.
    require('./app/controllers/pdf');
  });
  
  context('when the PdfGenerator returns successfully', () => {
    beforeEach(() => {
      // lazily declare our dependencies just for the block of tests for which
      // the setup is relevant.
      bottle.service('service.PdfGenerator', function createFakePdfGenerator() {
        generate = sinon.spy(() => 123);
        return generate;
      });
      
      // call the subject under test from the container.
      bottle.container.controller.Pdf.create({ params: { content_id: 456 } }, res);
    });
    
    it('invokes generate', () => {
      expect(generate).to.have.been.calledWith(456);
    });
    
    it('returns the pdf_id as json', () => {
      expect(res.json).to.have.been.calledWith({ pdf_id: 123 });
    });
  });

  context('when the PdfGenerator throws an error', () => {
    beforeEach(() => {
      // load alternative implementations for different scenario types.
      bottle.service('service.PdfGenerator', function createFakePdfGenerator() {
        generate = sinon.spy(() => {
          throw new Error('it all went wrong');
        });
        
        return generate;
      });
    });

    // ...
  });
});