// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import {assert} from 'chai';
import {isExperimentEnabled, SLO_EXPERIMENT} from './experiments.js';


describe('isExperimentEnabled', () => {
  it('throws error for unknown experiment', () => {
    assert.throws(() =>
      isExperimentEnabled('unknown-exp', {displayName: 'jessan@google.com'}));
  });

  it('returns false if user not in experiment', () => {
    const ineligibleUser = {displayName: 'example@example.com'};
    assert.isFalse(isExperimentEnabled(SLO_EXPERIMENT, ineligibleUser, {}));
  });

  it('returns false if no user provided', () => {
    assert.isFalse(isExperimentEnabled(SLO_EXPERIMENT, undefined, {}));
  });

  it('returns true if user in experiment', () => {
    const eligibleUser = {displayName: 'jessan@google.com'};
    assert.isTrue(isExperimentEnabled(SLO_EXPERIMENT, eligibleUser, {}));
  });

  it('is false if user in experiment has disabled it with URL', () => {
    const eligibleUser = {displayName: 'jessan@google.com'};
    assert.isFalse(isExperimentEnabled(
        SLO_EXPERIMENT, eligibleUser, {'e': '-slo'}));
  });

  it('ignores enabling experiments with URL', () => {
    const ineligibleUser = {displayName: 'example@example.com'};
    assert.isFalse(isExperimentEnabled(
        SLO_EXPERIMENT, ineligibleUser, {'e': 'slo'}));
  });

  it('ignores ineligible users disabling experiment with URL', () => {
    const ineligibleUser = {displayName: 'example@example.com'};
    assert.isFalse(isExperimentEnabled(
        SLO_EXPERIMENT, ineligibleUser, {'e': '-slo'}));
  });

  it('ignores invalid experiments in URL', () => {
    const eligibleUser = {displayName: 'jessan@google.com'};
    // Leading comma, unknown experiment str, empty experiment str in
    // middle, disable_str with no experiment, trailing comma
    assert.isFalse(isExperimentEnabled(
        SLO_EXPERIMENT, eligibleUser, {'e': ',unknown,-slo,,-,'}));
  });

  it('respects last instance when experiment repeated in URL', () => {
    const eligibleUser = {displayName: 'jessan@google.com'};
    assert.isFalse(isExperimentEnabled(
        SLO_EXPERIMENT, eligibleUser, {'e': 'slo,-slo'}));
    assert.isTrue(isExperimentEnabled(
        SLO_EXPERIMENT, eligibleUser, {'e': '-slo,slo'}));
  });
});