ui/src/common/feature_flags_unittest.ts

// Copyright (C) 2021 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import {FlagsForTesting as Flags, FlagStore} from './feature_flags';

class TestFlagStore implements FlagStore {
  o: object = {};

  load(): object {
    return this.o;
  }

  save(o: object): void {
    this.o = o;
  }
}

test('create flag', () => {
  const flags = new Flags(new TestFlagStore());
  const myFlag = flags.register({
    id: 'myFlag',
    defaultValue: false,
    description: '',
  });
  expect(myFlag.get()).toEqual(false);
  expect(myFlag.isOverridden()).toEqual(false);
});

test('registering the same flag twice is an error', () => {
  const flags = new Flags(new TestFlagStore());
  flags.register({
    id: 'foo',
    defaultValue: false,
    description: '',
  });
  expect(() => flags.register({
    id: 'foo',
    defaultValue: false,
    description: '',
  })).toThrow('Flag with id "foo" is already registered.');
});

test('can override', () => {
  const flags = new Flags(new TestFlagStore());
  const foo = flags.register({
    id: 'foo',
    defaultValue: false,
    description: '',
  });
  foo.set(true);
  expect(foo.isOverridden()).toEqual(true);
  expect(foo.get()).toEqual(true);
});

test('overrides are persisted', () => {
  const store = new TestFlagStore();
  const flagsA = new Flags(store);
  const fooA = flagsA.register({
    id: 'foo',
    defaultValue: true,
    description: 'some description',
  });

  fooA.set(true);

  const flagsB = new Flags(store);
  const fooB = flagsB.register({
    id: 'foo',
    defaultValue: false,
    description: 'a new description',
  });

  expect(fooB.get()).toEqual(true);
  expect(fooB.isOverridden()).toEqual(true);
});

test('flags can be reset', () => {
  const flags = new Flags(new TestFlagStore());
  const foo = flags.register({
    id: 'foo',
    defaultValue: false,
    description: 'some description',
  });

  foo.set(false);
  foo.reset();
  expect(foo.get()).toEqual(false);
  expect(foo.isOverridden()).toEqual(false);
});

test('corrupt store is ignored', () => {
  class Store {
    load(): object {
      return {'foo': 'bad state'};
    }

    save(_: object): void {}
  }
  const flags = new Flags(new Store());
  const foo = flags.register({
    id: 'foo',
    defaultValue: false,
    description: 'some description',
  });

  expect(foo.isOverridden()).toEqual(false);
});