Add some action creator tests

js/actionCreators.test.js

@@ -0,0 +1,125 @@
+import {BANDS} from './constants';
+import {
+  STOP,
+  SET_VOLUME,
+  SET_BALANCE,
+  TOGGLE_REPEAT,
+  TOGGLE_SHUFFLE,
+  SET_BAND_VALUE
+} from './actionTypes';
+
+import {
+  stop,
+  setVolume,
+  setBalance,
+  toggleRepeat,
+  toggleShuffle,
+  setPreamp,
+  setEqBand,
+  setEqToMax,
+  setEqToMin,
+  setEqToMid
+} from './actionCreators';
+
+test('stop', () => {
+  const expectedAction = {type: STOP};
+  expect(stop()).toEqual(expectedAction);
+});
+
+describe('setVolume', () => {
+  it('enforces a mimimum value', () => {
+    const expectedAction = {
+      type: SET_VOLUME,
+      volume: 0
+    };
+    expect(setVolume(-10)).toEqual(expectedAction);
+  });
+  it('enforces a maximum value', () => {
+    const expectedAction = {
+      type: SET_VOLUME,
+      volume: 100
+    };
+    expect(setVolume(110)).toEqual(expectedAction);
+  });
+});
+
+describe('setBalance', () => {
+  it('enforces a mimimum value', () => {
+    const expectedAction = {
+      type: SET_BALANCE,
+      balance: -100
+    };
+    expect(setBalance(-110)).toEqual(expectedAction);
+  });
+  it('enforces a maximum value', () => {
+    const expectedAction = {
+      type: SET_BALANCE,
+      balance: 100
+    };
+    expect(setBalance(110)).toEqual(expectedAction);
+  });
+  it('snaps to zero for positive values close to zero', () => {
+    const expectedAction = {
+      type: SET_BALANCE,
+      balance: 0
+    };
+    expect(setBalance(24)).toEqual(expectedAction);
+  });
+  it('snaps to zero for negative values close to zero', () => {
+    const expectedAction = {
+      type: SET_BALANCE,
+      balance: 0
+    };
+    expect(setBalance(-24)).toEqual(expectedAction);
+  });
+});
+
+test('toggleRepeat', () => {
+  const expectedAction = {type: TOGGLE_REPEAT};
+  expect(toggleRepeat()).toEqual(expectedAction);
+});
+
+test('toggleShuffle', () => {
+  const expectedAction = {type: TOGGLE_SHUFFLE};
+  expect(toggleShuffle()).toEqual(expectedAction);
+});
+
+test('setPreamp', () => {
+  const expectedAction = {type: SET_BAND_VALUE, band: 'preamp', value: 100};
+  expect(setPreamp(100)).toEqual(expectedAction);
+});
+
+test('setEqBand', () => {
+  const expectedAction = {type: SET_BAND_VALUE, band: 3, value: 100};
+  expect(setEqBand(3, 100)).toEqual(expectedAction);
+});
+
+test('setEqToMax', () => {
+  const mockDispatch = jest.fn();
+  const dispatcher = setEqToMax();
+  dispatcher(mockDispatch);
+  const expectedCalls = BANDS.map((band) => (
+    [{type: SET_BAND_VALUE, band, value: 100}]
+  ));
+  expect(mockDispatch.mock.calls).toEqual(expectedCalls);
+});
+
+test('setEqToMin', () => {
+  const mockDispatch = jest.fn();
+  const dispatcher = setEqToMin();
+  dispatcher(mockDispatch);
+  const expectedCalls = BANDS.map((band) => (
+    [{type: SET_BAND_VALUE, band, value: 0}]
+  ));
+  expect(mockDispatch.mock.calls).toEqual(expectedCalls);
+});
+
+test('setEqToMid', () => {
+  const mockDispatch = jest.fn();
+  const dispatcher = setEqToMid();
+  dispatcher(mockDispatch);
+  const expectedCalls = BANDS.map((band) => (
+    [{type: SET_BAND_VALUE, band, value: 50}]
+  ));
+  expect(mockDispatch.mock.calls).toEqual(expectedCalls);
+});