Merge pull request #4803 from matrix-org/travis/room-list/setting-diff

Only fire setting changes for changed settings

src/utils/WidgetUtils.js

@@ -31,6 +31,7 @@ import {IntegrationManagers} from "../integrations/IntegrationManagers";
 import {Capability} from "../widgets/WidgetApi";
 import {Room} from "matrix-js-sdk/src/models/room";
 import {WidgetType} from "../widgets/WidgetType";
+import {objectClone} from "./objects";
 
 export default class WidgetUtils {
     /* Returns true if user is able to send state events to modify widgets in this room
@@ -222,7 +223,7 @@ export default class WidgetUtils {
         const client = MatrixClientPeg.get();
         // Get the current widgets and clone them before we modify them, otherwise
         // we'll modify the content of the old event.
-        const userWidgets = JSON.parse(JSON.stringify(WidgetUtils.getUserWidgets()));
+        const userWidgets = objectClone(WidgetUtils.getUserWidgets());
 
         // Delete existing widget with ID
         try {

src/utils/arrays.ts

@@ -46,6 +46,28 @@ export function arrayDiff<T>(a: T[], b: T[]): { added: T[], removed: T[] } {
     };
 }
 
+/**
+ * Returns the union of two arrays.
+ * @param a The first array. Must be defined.
+ * @param b The second array. Must be defined.
+ * @returns The union of the arrays.
+ */
+export function arrayUnion<T>(a: T[], b: T[]): T[] {
+    return a.filter(i => b.includes(i));
+}
+
+/**
+ * Merges arrays, deduping contents using a Set.
+ * @param a The arrays to merge.
+ * @returns The merged array.
+ */
+export function arrayMerge<T>(...a: T[][]): T[] {
+    return Array.from(a.reduce((c, v) => {
+        v.forEach(i => c.add(i));
+        return c;
+    }, new Set<T>()));
+}
+
 /**
  * Helper functions to perform LINQ-like queries on arrays.
  */

src/utils/objects.ts

@@ -0,0 +1,60 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+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 { arrayDiff, arrayMerge, arrayUnion } from "./arrays";
+
+/**
+ * Determines the keys added, changed, and removed between two objects.
+ * For changes, simple triple equal comparisons are done, not in-depth
+ * tree checking.
+ * @param a The first object. Must be defined.
+ * @param b The second object. Must be defined.
+ * @returns The difference between the keys of each object.
+ */
+export function objectDiff(a: any, b: any): { changed: string[], added: string[], removed: string[] } {
+    const aKeys = Object.keys(a);
+    const bKeys = Object.keys(b);
+    const keyDiff = arrayDiff(aKeys, bKeys);
+    const possibleChanges = arrayUnion(aKeys, bKeys);
+    const changes = possibleChanges.filter(k => a[k] !== b[k]);
+
+    return {changed: changes, added: keyDiff.added, removed: keyDiff.removed};
+}
+
+/**
+ * Gets all the key changes (added, removed, or value difference) between
+ * two objects. Triple equals is used to compare values, not in-depth tree
+ * checking.
+ * @param a The first object. Must be defined.
+ * @param b The second object. Must be defined.
+ * @returns The keys which have been added, removed, or changed between the
+ * two objects.
+ */
+export function objectKeyChanges(a: any, b: any): string[] {
+    const diff = objectDiff(a, b);
+    return arrayMerge(diff.removed, diff.added, diff.changed);
+}
+
+/**
+ * Clones an object by running it through JSON parsing. Note that this
+ * will destroy any complicated object types which do not translate to
+ * JSON.
+ * @param obj The object to clone.
+ * @returns The cloned object
+ */
+export function objectClone(obj: any): any {
+    return JSON.parse(JSON.stringify(obj));
+}