fix(ivy): ngClass not applying classes with trailing/leading spaces (#34539)

Fixes classes with trailing or leading space that are passed to `ngClass` (e.g. `{'foo ': bar}`) not being applied in Ivy. The issue comes from the fact that when the styling differ builds up the style map it uses the trimmed key to look up the value in the map that uses non-trimmed keys.

Fixes #34476.

PR Close #34539

packages/common/src/directives/styling_differ.ts

@@ -212,11 +212,11 @@ function bulidMapFromValues(
     // case 1: map
     for (let i = 0; i < keys.length; i++) {
       let key = keys[i];
-      key = trim ? key.trim() : key;
       const value = (values as{[key: string]: any})[key];
 
       if (value !== undefined) {
-        setMapValues(map, key, value, parseOutUnits, allowSubKeys);
+        // Map uses untrimmed keys, so don't trim until passing to `setMapValues`
+        setMapValues(map, trim ? key.trim() : key, value, parseOutUnits, allowSubKeys);
       }
     }
   } else {

packages/core/test/acceptance/styling_spec.ts

@@ -2485,6 +2485,28 @@ describe('styling', () => {
     const div = fixture.nativeElement.querySelector('div');
     expect(getComputedStyle(div).width).toBe('10px');
   });
+
+  it('should allow classes with trailing and leading spaces in [ngClass]', () => {
+    @Component({
+      template: `
+        <div leading-space [ngClass]="{' foo': applyClasses}"></div>
+        <div trailing-space [ngClass]="{'foo ': applyClasses}"></div>
+      `
+    })
+    class Cmp {
+      applyClasses = true;
+    }
+
+    TestBed.configureTestingModule({declarations: [Cmp]});
+    const fixture = TestBed.createComponent(Cmp);
+    fixture.detectChanges();
+
+    const leading = fixture.nativeElement.querySelector('[leading-space]');
+    const trailing = fixture.nativeElement.querySelector('[trailing-space]');
+    expect(leading.className).toBe('foo', 'Expected class to be applied despite leading space.');
+    expect(trailing.className).toBe('foo', 'Expected class to be applied despite trailing space.');
+  });
+
 });
 
 function assertStyleCounters(countForSet: number, countForRemove: number) {