Jest environment variable testing

jest-test-env-variables.md

Simple example that demonstrates how to test environment variables from Jest

describe('models/env unit tests', () => {
  function importTestedModule() {
    return require('../../../src').models; // eslint-disable-line
  }

  beforeEach(() => {
    jest.resetModules();
  });

  test('env is set', () => {
    process.env.TABLE_NAME = 'foo';
    const { env } = importTestedModule();
    const result = env.getTableName();
    expect(result).toEqual('foo');
  });

  test('env is not set', () => {
    delete process.env.TABLE_NAME;
    const { env } = importTestedModule();
    const result = env.getTableName();
    expect(result).toEqual('default-table-name');
  });
});

const TableName = process.env.TABLE_NAME || 'default-table-name';

function getTableName() {
  return TableName;
}

module.exports = {
  getTableName
};