fix(forms): allow resetting with empty string

JeanMeche · alxhub · commit cbb10179c809 · 2025-12-10T10:04:58.000-08:00
Both empty string and null values should be accepted when resetting fixes #65949 (cherry picked from commit 14713d0)
diff --git a/packages/forms/signals/src/field/node.ts b/packages/forms/signals/src/field/node.ts
@@ -228,7 +228,7 @@ export class FieldNode implements FieldState<unknown> {
   }
 
   private _reset(value?: unknown) {
-    if (value) {
+    if (value !== undefined) {
       this.value.set(value);
     }
 
diff --git a/packages/forms/signals/test/node/field_node.spec.ts b/packages/forms/signals/test/node/field_node.spec.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import {computed, effect, Injector, signal} from '@angular/core';
+import {computed, effect, Injector, signal, WritableSignal} from '@angular/core';
 import {TestBed} from '@angular/core/testing';
 import {
   apply,
@@ -121,6 +121,41 @@ describe('FieldNode', () => {
       f().reset();
       expect(f.a().value()).toBe(1);
     });
+
+    it('can reset with empty string', () => {
+      const model = signal('hello');
+      const f = form(model, {injector: TestBed.inject(Injector)});
+      f().reset('');
+      expect(f().value()).toBe('');
+    });
+
+    it('can reset with false', () => {
+      const model = signal(true);
+      const f = form(model, {injector: TestBed.inject(Injector)});
+      f().reset(false);
+      expect(f().value()).toBe(false);
+    });
+
+    it('can reset with null', () => {
+      const model: WritableSignal<string | null> = signal('hello');
+      const f = form(model, {injector: TestBed.inject(Injector)});
+      f().reset(null);
+      expect(f().value()).toBeNull();
+    });
+
+    it('can reset with 0', () => {
+      const model = signal(5);
+      const f = form(model, {injector: TestBed.inject(Injector)});
+      f().reset(0);
+      expect(f().value()).toBe(0);
+    });
+
+    it('can reset with NaN', () => {
+      const model = signal(5);
+      const f = form(model, {injector: TestBed.inject(Injector)});
+      f().reset(NaN);
+      expect(f().value()).toBeNaN();
+    });
   });
 
   describe('dirty', () => {

Original file line number	Diff line number	Diff line change
`@@ -228,7 +228,7 @@ export class FieldNode implements FieldState<unknown> {`
`228`	`228`	`}`
`229`	`229`
`230`	`230`	`private _reset(value?: unknown) {`
`231`		`- if (value) {`
	`231`	`+ if (value !== undefined) {`
`232`	`232`	`this.value.set(value);`
`233`	`233`	`}`
`234`	`234`