fix(common): re-sort output of `KeyValuePipe` when `compareFn` changes (#42821)

Previously, if only the `compareFn` changed but the data itself did not, then
the `KeyValuePipe` did not re-sort the output.

Fixes #42819

PR Close #42821

packages/common/src/pipes/keyvalue_pipe.ts

@@ -49,6 +49,7 @@ export class KeyValuePipe implements PipeTransform {
 
   private differ!: KeyValueDiffer<any, any>;
   private keyValues: Array<KeyValue<any, any>> = [];
+  private compareFn: (a: KeyValue<any, any>, b: KeyValue<any, any>) => number = defaultComparator;
 
   /*
    * NOTE: when the `input` value is a simple Record<K, V> object, the keys are extracted with
@@ -91,13 +92,17 @@ export class KeyValuePipe implements PipeTransform {
     }
 
     const differChanges: KeyValueChanges<K, V>|null = this.differ.diff(input as any);
+    const compareFnChanged = compareFn !== this.compareFn;
 
     if (differChanges) {
       this.keyValues = [];
       differChanges.forEachItem((r: KeyValueChangeRecord<K, V>) => {
         this.keyValues.push(makeKeyValuePair(r.key, r.currentValue!));
       });
+    }
+    if (differChanges || compareFnChanged) {
       this.keyValues.sort(compareFn);
+      this.compareFn = compareFn;
     }
     return this.keyValues;
   }

packages/common/test/pipes/keyvalue_pipe_spec.ts

@@ -51,6 +51,15 @@ describe('KeyValuePipe', () => {
         {key: 'a', value: 1}, {key: 'b', value: 1}
       ]);
     });
+    it('should reorder when compareFn changes', () => {
+      const pipe = new KeyValuePipe(defaultKeyValueDiffers);
+      const input = {'b': 1, 'a': 2};
+      pipe.transform<string, number>(input);
+      expect(pipe.transform<string, number>(input, (a, b) => a.value - b.value)).toEqual([
+        {key: 'b', value: 1},
+        {key: 'a', value: 2},
+      ]);
+    });
     it('should return the same ref if nothing changes', () => {
       const pipe = new KeyValuePipe(defaultKeyValueDiffers);
       const transform1 = pipe.transform({1: 2});
@@ -114,6 +123,15 @@ describe('KeyValuePipe', () => {
             {key: {id: 1}, value: 1},
           ]);
     });
+    it('should reorder when compareFn changes', () => {
+      const pipe = new KeyValuePipe(defaultKeyValueDiffers);
+      const input = new Map([['b', 1], ['a', 2]]);
+      pipe.transform<string, number>(input);
+      expect(pipe.transform<string, number>(input, (a, b) => a.value - b.value)).toEqual([
+        {key: 'b', value: 1},
+        {key: 'a', value: 2},
+      ]);
+    });
     it('should return the same ref if nothing changes', () => {
       const pipe = new KeyValuePipe(defaultKeyValueDiffers);
       const transform1 = pipe.transform(new Map([[1, 2]]));