randomSeed.test.js

import Chance from 'chance';

const seedGenerator = new Chance()
const seed = process.env.SEED || seedGenerator.hash();

const chance = new Chance(seed);

const functionUnderTest = (input) => {
  return input.veryImportant
}

describe('Simple test', () => {
  it('Expects something to happen', () => {
    const inputString = chance.string();
    const testData = {
	input: inputString,
	expectedOutput: inputString
    }
    const config = {
      veryImportant: testData.input
    };
    const result = functionUnderTest(config);
    expect(result).toBe(testData.expectedOutput);
  });
});