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angular__angular/devtools/projects/ng-devtools/src/lib/devtools-tabs/diffing/index.ts
T
AleksanderBodurri 2a1ff17b42 refactor(devtools): run tslint --fix on devtools codebase
This commit runs tslint --fix with the angular/angular tslint configuration on the files inside the devtools codebase.

Notably, the file-header rule in `tslint.json` was missing a default attribute. This commit adds that default attribute and sets it to the
license header that is present in all files in this repo. After running tslint --fix with this default added, this commit added the license header to all files in the devtools directory. Note for the reviewer: the automatically added license headers were added as comments with the "/*!" prefix. Since we want these comments removed in builds, and the rest of the codebase uses "/**", a simple find and replace was performed on the devtools directory to change these prefixes to "/**".
2022-01-26 16:35:31 -05:00

93 lines
3.2 KiB
TypeScript

/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
// tslint:disable-next-line:deprecation
import {DefaultIterableDiffer} from '@angular/core';
export interface MovedRecord {
currentIndex: number;
previousIndex: number;
}
export const diff = <T>(differ: DefaultIterableDiffer<T>, a: T[], b: T[]):
{newItems: T[]; removedItems: T[]; movedItems: T[];} => {
differ.diff(a);
differ.diff(b);
const alreadySet: boolean[] = [];
const movedItems: T[] = [];
// We first have to set the moved items to their correct positions.
// Keep in mind that the track by function may not guarantee
// that we haven't changed any of the items' props.
differ.forEachMovedItem(record => {
if (record.currentIndex === null) {
return;
}
if (record.previousIndex === null) {
return;
}
// We want to preserve the reference so that a default
// track by function used by the CDK, for instance, can
// recognize that this item's identity hasn't changed.
// At the same time, since we don't have the guarantee
// that we haven't already set the previousIndex while
// iterating, we need to check that. If we have, we assign
// this array item to a new object. We don't want to risk
// changing the properties of an object we'll use in the future.
if (!alreadySet[record.previousIndex]) {
a[record.currentIndex] = a[record.previousIndex];
} else {
a[record.currentIndex] = {} as T;
}
Object.keys(b[record.currentIndex]).forEach(prop => {
// TypeScript's type inference didn't follow the check from above.
if (record.currentIndex === null) {
return;
}
a[record.currentIndex][prop] = b[record.currentIndex][prop];
});
if (!alreadySet[record.previousIndex]) {
// tslint:disable-next-line: no-non-null-assertion
a[record.previousIndex] = null!;
}
alreadySet[record.currentIndex] = true;
movedItems.push(a[record.currentIndex]);
});
// Now we can set the new items and remove the deleted ones.
const newItems: T[] = [];
const removedItems: T[] = [];
differ.forEachAddedItem(record => {
if (record.currentIndex !== null && record.previousIndex === null) {
a[record.currentIndex] = record.item;
alreadySet[record.currentIndex] = true;
newItems.push(record.item);
}
});
differ.forEachRemovedItem(record => {
if (record.previousIndex === null) {
return;
}
if (record.currentIndex === null && !alreadySet[record.previousIndex]) {
// tslint:disable-next-line: no-non-null-assertion
a[record.previousIndex] = null!;
}
removedItems.push(record.item);
});
for (let i = a.length - 1; i >= 0; i--) {
if (a[i] === null) {
a.splice(i, 1);
}
}
return {newItems, removedItems, movedItems};
};