react-native/Libraries/Lists/__tests__/ViewabilityHelper-test.js

372 lines
11 KiB
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
*
* @format
*/
'use strict';
const ViewabilityHelper = require('ViewabilityHelper');
let rowFrames;
let data;
function getFrameMetrics(index: number) {
const frame = rowFrames[data[index].key];
return {length: frame.height, offset: frame.y};
}
function createViewToken(index: number, isViewable: boolean) {
return {key: data[index].key, isViewable};
}
describe('computeViewableItems', function() {
it('returns all 4 entirely visible rows as viewable', function() {
const helper = new ViewabilityHelper({
viewAreaCoveragePercentThreshold: 50,
});
rowFrames = {
a: {y: 0, height: 50},
b: {y: 50, height: 50},
c: {y: 100, height: 50},
d: {y: 150, height: 50},
};
data = [{key: 'a'}, {key: 'b'}, {key: 'c'}, {key: 'd'}];
expect(
helper.computeViewableItems(data.length, 0, 200, getFrameMetrics),
).toEqual([0, 1, 2, 3]);
});
it('returns top 2 rows as viewable (1. entirely visible and 2. majority)', function() {
const helper = new ViewabilityHelper({
viewAreaCoveragePercentThreshold: 50,
});
rowFrames = {
a: {y: 0, height: 50},
b: {y: 50, height: 150},
c: {y: 200, height: 50},
d: {y: 250, height: 50},
};
data = [{key: 'a'}, {key: 'b'}, {key: 'c'}, {key: 'd'}];
expect(
helper.computeViewableItems(data.length, 0, 200, getFrameMetrics),
).toEqual([0, 1]);
});
it('returns only 2nd row as viewable (majority)', function() {
const helper = new ViewabilityHelper({
viewAreaCoveragePercentThreshold: 50,
});
rowFrames = {
a: {y: 0, height: 50},
b: {y: 50, height: 150},
c: {y: 200, height: 50},
d: {y: 250, height: 50},
};
data = [{key: 'a'}, {key: 'b'}, {key: 'c'}, {key: 'd'}];
expect(
helper.computeViewableItems(data.length, 25, 200, getFrameMetrics),
).toEqual([1]);
});
it('handles empty input', function() {
const helper = new ViewabilityHelper({
viewAreaCoveragePercentThreshold: 50,
});
rowFrames = {};
data = [];
expect(
helper.computeViewableItems(data.length, 0, 200, getFrameMetrics),
).toEqual([]);
});
it('handles different view area coverage percent thresholds', function() {
rowFrames = {
a: {y: 0, height: 50},
b: {y: 50, height: 150},
c: {y: 200, height: 500},
d: {y: 700, height: 50},
};
data = [{key: 'a'}, {key: 'b'}, {key: 'c'}, {key: 'd'}];
let helper = new ViewabilityHelper({viewAreaCoveragePercentThreshold: 0});
expect(
helper.computeViewableItems(data.length, 0, 50, getFrameMetrics),
).toEqual([0]);
expect(
helper.computeViewableItems(data.length, 1, 50, getFrameMetrics),
).toEqual([0, 1]);
expect(
helper.computeViewableItems(data.length, 199, 50, getFrameMetrics),
).toEqual([1, 2]);
expect(
helper.computeViewableItems(data.length, 250, 50, getFrameMetrics),
).toEqual([2]);
helper = new ViewabilityHelper({viewAreaCoveragePercentThreshold: 100});
expect(
helper.computeViewableItems(data.length, 0, 200, getFrameMetrics),
).toEqual([0, 1]);
expect(
helper.computeViewableItems(data.length, 1, 200, getFrameMetrics),
).toEqual([1]);
expect(
helper.computeViewableItems(data.length, 400, 200, getFrameMetrics),
).toEqual([2]);
expect(
helper.computeViewableItems(data.length, 600, 200, getFrameMetrics),
).toEqual([3]);
helper = new ViewabilityHelper({viewAreaCoveragePercentThreshold: 10});
expect(
helper.computeViewableItems(data.length, 30, 200, getFrameMetrics),
).toEqual([0, 1, 2]);
expect(
helper.computeViewableItems(data.length, 31, 200, getFrameMetrics),
).toEqual([1, 2]);
});
it('handles different item visible percent thresholds', function() {
rowFrames = {
a: {y: 0, height: 50},
b: {y: 50, height: 150},
c: {y: 200, height: 50},
d: {y: 250, height: 50},
};
data = [{key: 'a'}, {key: 'b'}, {key: 'c'}, {key: 'd'}];
let helper = new ViewabilityHelper({itemVisiblePercentThreshold: 0});
expect(
helper.computeViewableItems(data.length, 0, 50, getFrameMetrics),
).toEqual([0]);
expect(
helper.computeViewableItems(data.length, 1, 50, getFrameMetrics),
).toEqual([0, 1]);
helper = new ViewabilityHelper({itemVisiblePercentThreshold: 100});
expect(
helper.computeViewableItems(data.length, 0, 250, getFrameMetrics),
).toEqual([0, 1, 2]);
expect(
helper.computeViewableItems(data.length, 1, 250, getFrameMetrics),
).toEqual([1, 2]);
helper = new ViewabilityHelper({itemVisiblePercentThreshold: 10});
expect(
helper.computeViewableItems(data.length, 184, 20, getFrameMetrics),
).toEqual([1]);
expect(
helper.computeViewableItems(data.length, 185, 20, getFrameMetrics),
).toEqual([1, 2]);
expect(
helper.computeViewableItems(data.length, 186, 20, getFrameMetrics),
).toEqual([2]);
});
});
describe('onUpdate', function() {
it('returns 1 visible row as viewable then scrolls away', function() {
const helper = new ViewabilityHelper();
rowFrames = {
a: {y: 0, height: 50},
};
data = [{key: 'a'}];
const onViewableItemsChanged = jest.fn();
helper.onUpdate(
data.length,
0,
200,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
expect(onViewableItemsChanged.mock.calls.length).toBe(1);
expect(onViewableItemsChanged.mock.calls[0][0]).toEqual({
changed: [{isViewable: true, key: 'a'}],
viewableItems: [{isViewable: true, key: 'a'}],
});
helper.onUpdate(
data.length,
0,
200,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
expect(onViewableItemsChanged.mock.calls.length).toBe(1); // nothing changed!
helper.onUpdate(
data.length,
100,
200,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
expect(onViewableItemsChanged.mock.calls.length).toBe(2);
expect(onViewableItemsChanged.mock.calls[1][0]).toEqual({
changed: [{isViewable: false, key: 'a'}],
viewableItems: [],
});
});
it('returns 1st visible row then 1st and 2nd then just 2nd', function() {
const helper = new ViewabilityHelper();
rowFrames = {
a: {y: 0, height: 200},
b: {y: 200, height: 200},
};
data = [{key: 'a'}, {key: 'b'}];
const onViewableItemsChanged = jest.fn();
helper.onUpdate(
data.length,
0,
200,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
expect(onViewableItemsChanged.mock.calls.length).toBe(1);
expect(onViewableItemsChanged.mock.calls[0][0]).toEqual({
changed: [{isViewable: true, key: 'a'}],
viewableItems: [{isViewable: true, key: 'a'}],
});
helper.onUpdate(
data.length,
100,
200,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
expect(onViewableItemsChanged.mock.calls.length).toBe(2);
// Both visible with 100px overlap each
expect(onViewableItemsChanged.mock.calls[1][0]).toEqual({
changed: [{isViewable: true, key: 'b'}],
viewableItems: [
{isViewable: true, key: 'a'},
{isViewable: true, key: 'b'},
],
});
helper.onUpdate(
data.length,
200,
200,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
expect(onViewableItemsChanged.mock.calls.length).toBe(3);
expect(onViewableItemsChanged.mock.calls[2][0]).toEqual({
changed: [{isViewable: false, key: 'a'}],
viewableItems: [{isViewable: true, key: 'b'}],
});
});
it('minimumViewTime delays callback', function() {
const helper = new ViewabilityHelper({
minimumViewTime: 350,
viewAreaCoveragePercentThreshold: 0,
});
rowFrames = {
a: {y: 0, height: 200},
b: {y: 200, height: 200},
};
data = [{key: 'a'}, {key: 'b'}];
const onViewableItemsChanged = jest.fn();
helper.onUpdate(
data.length,
0,
200,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
expect(onViewableItemsChanged).not.toBeCalled();
jest.runAllTimers();
expect(onViewableItemsChanged.mock.calls.length).toBe(1);
expect(onViewableItemsChanged.mock.calls[0][0]).toEqual({
changed: [{isViewable: true, key: 'a'}],
viewableItems: [{isViewable: true, key: 'a'}],
});
});
it('minimumViewTime skips briefly visible items', function() {
const helper = new ViewabilityHelper({
minimumViewTime: 350,
viewAreaCoveragePercentThreshold: 0,
});
rowFrames = {
a: {y: 0, height: 250},
b: {y: 250, height: 200},
};
data = [{key: 'a'}, {key: 'b'}];
const onViewableItemsChanged = jest.fn();
helper.onUpdate(
data.length,
0,
200,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
helper.onUpdate(
data.length,
300, // scroll past item 'a'
200,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
jest.runAllTimers();
expect(onViewableItemsChanged.mock.calls.length).toBe(1);
expect(onViewableItemsChanged.mock.calls[0][0]).toEqual({
changed: [{isViewable: true, key: 'b'}],
viewableItems: [{isViewable: true, key: 'b'}],
});
});
it('waitForInteraction blocks callback until interaction', function() {
const helper = new ViewabilityHelper({
waitForInteraction: true,
viewAreaCoveragePercentThreshold: 0,
});
rowFrames = {
a: {y: 0, height: 200},
b: {y: 200, height: 200},
};
data = [{key: 'a'}, {key: 'b'}];
const onViewableItemsChanged = jest.fn();
helper.onUpdate(
data.length,
0,
100,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
expect(onViewableItemsChanged).not.toBeCalled();
helper.recordInteraction();
helper.onUpdate(
data.length,
20,
100,
getFrameMetrics,
createViewToken,
onViewableItemsChanged,
);
expect(onViewableItemsChanged.mock.calls.length).toBe(1);
expect(onViewableItemsChanged.mock.calls[0][0]).toEqual({
changed: [{isViewable: true, key: 'a'}],
viewableItems: [{isViewable: true, key: 'a'}],
});
});
});