it('should treat null as an empty list', () => {
differ.diff(['a', 'b']);
expect(iterableDifferToString(differ.diff(null !) !)).toEqual(iterableChangesAsString({
previous: ['a[0->null]', 'b[1->null]'],
removals: ['a[0->null]', 'b[1->null]']
}));
});
it('should ignore [NaN] != [NaN]', () => {
const l = [NaN];
differ.check(l);
differ.check(l);
expect(iterableDifferToString(differ))
.toEqual(iterableChangesAsString({collection: [NaN], previous: [NaN]}));
});
it('should track removals normally', () => {
differ.check(['a', 'b', 'c', 'd']);
differ.check(['e', 'f', 'g', 'h']);
differ.check(['e', 'f', 'h']);
expect(iterableDifferToString(differ)).toEqual(iterableChangesAsString({
collection: ['e', 'f', 'h'],
previous: ['e', 'f', 'h', 'h[3->null]'],
removals: ['h[3->null]'],
identityChanges: ['h']
}));
});
it('should support insertions/moves', () => {
const l = ['a', 'a', 'b', 'b'];
differ.check(l);
l.splice(0, 0, 'b');
differ.check(l);
expect(iterableDifferToString(differ)).toEqual(iterableChangesAsString({
collection: ['b[2->0]', 'a[0->1]', 'a[1->2]', 'b', 'b[null->4]'],
previous: ['a[0->1]', 'a[1->2]', 'b[2->0]', 'b'],
additions: ['b[null->4]'],
moves: ['b[2->0]', 'a[0->1]', 'a[1->2]']
}));
});
it('should support duplicates', () => {
const l = ['a', 'a', 'a', 'b', 'b'];
differ.check(l);
l.splice(0, 1);
differ.check(l);
expect(iterableDifferToString(differ)).toEqual(iterableChangesAsString({
collection: ['a', 'a', 'b[3->2]', 'b[4->3]'],
previous: ['a', 'a', 'a[2->null]', 'b[3->2]', 'b[4->3]'],
moves: ['b[3->2]', 'b[4->3]'],
removals: ['a[2->null]']
}));
});
it('should detect [NaN] moves', () => {
const l: any[] = [NaN, NaN];
differ.check(l);
l.unshift('foo');
differ.check(l);
expect(iterableDifferToString(differ)).toEqual(iterableChangesAsString({
collection: ['foo[null->0]', 'NaN[0->1]', 'NaN[1->2]'],
previous: ['NaN[0->1]', 'NaN[1->2]'],
additions: ['foo[null->0]'],
moves: ['NaN[0->1]', 'NaN[1->2]']
}));
});
it('support re-insertion', () => {
const l = ['a', '*', '*', 'd', '-', '-', '-', 'e'];
differ.check(l);
l[1] = 'b';
l[5] = 'c';
differ.check(l);
expect(iterableDifferToString(differ)).toEqual(iterableChangesAsString({
collection: ['a', 'b[null->1]', '*[1->2]', 'd', '-', 'c[null->5]', '-[5->6]', 'e'],
previous: ['a', '*[1->2]', '*[2->null]', 'd', '-', '-[5->6]', '-[6->null]', 'e'],
additions: ['b[null->1]', 'c[null->5]'],
moves: ['*[1->2]', '-[5->6]'],
removals: ['*[2->null]', '-[6->null]'],
}));
});
it('should handle swapping element', () => {
const l = [1, 2];
differ.check(l);
l.length = 0;
l.push(2);
l.push(1);
differ.check(l);
expect(iterableDifferToString(differ)).toEqual(iterableChangesAsString({
collection: ['2[1->0]', '1[0->1]'],
previous: ['1[0->1]', '2[1->0]'],
moves: ['2[1->0]', '1[0->1]']
}));
});
it('should not report unnecessary moves', () => {
const l = ['a', 'b', 'c'];
differ.check(l);
l.length = 0;
l.push('b');
l.push('a');
l.push('c');
differ.check(l);
expect(iterableDifferToString(differ)).toEqual(iterableChangesAsString({
collection: ['b[1->0]', 'a[0->1]', 'c'],
previous: ['a[0->1]', 'b[1->0]', 'c'],
moves: ['b[1->0]', 'a[0->1]']
}));
});
() => {
differ = new DefaultIterableDiffer((index: number) => index);
const startData = [1, 2, 3, 4];
const endData = [5, 6, 7, 8];
differ = differ.diff(startData) !;
differ = differ.diff(endData) !;
const operations: string[] = [];
differ.forEachOperation((item: any, prev: number, next: number) => {
const value = modifyArrayUsingOperation(startData, endData, prev, next);
operations.push(stringifyItemChange(item, prev, next, item.previousIndex));
});
expect(operations).toEqual([]);
});
