Hey,

I'd like to get your opinions on introducing Jest for unit testing on the backend and then secondary to that, creating a way to create test data for the unit tests.

I would propose changing a few structures first, for our controllers we have the file paths of

Controllers

controllers/erpControllers/adminController.js

I would propose to change this to

controllers/erpControllers/adminController/index.js
controllers/erpControllers/adminController/index.test.js

This could then be extended later to include index.test.integration.ts for integration tests.

Models

Currently we have our model files like so

models/erpModels/Admin.js

I'd like to change this so that a model can also have a generator to create the test data for that model.

models/erpModels/Admin/index.js
models/erpModels/Admin/generate.js

Generate.js

The generate.js would look something like:

const faker = require('@faker-js/faker');
const Admin = mongoose.model('Admin');

const generateAdmin = (input) => {
  return new Admin({
    ...input,
    surname: faker.name.lastName(),
    // More fields here
  })
}

export default generateAdmin

Test Data

We would want a way to create test data on the fly for whatever purpose it is required and be able to relate the data. I'd propose something like below:

    await resetDatabase({
      testData: {
        Admin: [{}],
        Employee: [{}, {}, {}],
        Expense: [{ expenseCategory: 0 }],
        ExpenseCategory: [{}]
      },
    });

This would create:

1 Admin, 3 Employee's, 1 Expensive which has an Expense cateogry and 1 Expense Category that belongs to an Expense