fix(forms): minor cleanup for disabled API (#63318)

* fix(forms): minor cleanup for disabled API

rename DisabledReason.reason to DisabledReason.message for consistency with errors, and allow unconditional disabling with message

* address feedback

goldens/public-api/forms/signals/index.api.md

@@ -100,12 +100,12 @@ export class CustomValidationError extends ValidationError {
 }
 
 // @public
-export function disabled<TValue, TPathKind extends PathKind = PathKind.Root>(path: FieldPath<TValue, TPathKind>, logic?: NoInfer<LogicFn<TValue, boolean | string, TPathKind>>): void;
+export function disabled<TValue, TPathKind extends PathKind = PathKind.Root>(path: FieldPath<TValue, TPathKind>, logic?: string | NoInfer<LogicFn<TValue, boolean | string, TPathKind>>): void;
 
 // @public
 export interface DisabledReason {
     readonly field: Field<unknown>;
-    readonly reason?: string;
+    readonly message?: string;
 }
 
 // @public

packages/forms/signals/docs/signal-forms.md

@@ -530,7 +530,7 @@ const userSchema = schema<User>((userPath) => {
     this.usersModel.set([{username: 'newuser', name: 'John Doe'}]);
 
     this.usersForm[0].username().disabled(); // true
-    this.usersForm[0].username().disabledReasons(); // [{field: this.usersForm[0].username, reason: 'Username cannot be changed'}]
+    this.usersForm[0].username().disabledReasons(); // [{field: this.usersForm[0].username, message: 'Username cannot be changed'}]
   }
 }
 ```

packages/forms/signals/src/api/logic.ts

@@ -31,23 +31,22 @@ import {addDefaultField} from './validation_errors';
  */
 export function disabled<TValue, TPathKind extends PathKind = PathKind.Root>(
   path: FieldPath<TValue, TPathKind>,
-  logic: NoInfer<LogicFn<TValue, boolean | string, TPathKind>> = () => true,
+  logic?: string | NoInfer<LogicFn<TValue, boolean | string, TPathKind>>,
 ): void {
   assertPathIsCurrent(path);
 
   const pathNode = FieldPathNode.unwrapFieldPath(path);
   pathNode.logic.addDisabledReasonRule((ctx) => {
-    const result = logic(ctx as FieldContext<TValue, TPathKind>);
-    if (!result) {
-      return undefined;
+    let result: boolean | string = true;
+    if (typeof logic === 'string') {
+      result = logic;
+    } else if (logic) {
+      result = logic(ctx as FieldContext<TValue, TPathKind>);
     }
     if (typeof result === 'string') {
-      return {
-        field: ctx.field,
-        reason: result,
-      };
+      return {field: ctx.field, message: result};
     }
-    return {field: ctx.field};
+    return result ? {field: ctx.field} : undefined;
   });
 }
 

packages/forms/signals/src/api/types.ts

@@ -72,8 +72,8 @@ export type SubmittedStatus = 'unsubmitted' | 'submitted' | 'submitting';
 export interface DisabledReason {
   /** The field that is disabled. */
   readonly field: Field<unknown>;
-  /** The reason for the disablement. */
-  readonly reason?: string;
+  /** A user-facing message describing the reason for the disablement. */
+  readonly message?: string;
 }
 
 /** The absence of an error which indicates a successful validation result. */

packages/forms/signals/test/node/field_node.spec.ts

@@ -405,7 +405,7 @@ describe('FieldNode', () => {
       expect(f.a().disabledReasons()).toEqual([
         {
           field: f.a,
-          reason: 'a cannot be changed',
+          message: 'a cannot be changed',
         },
       ]);
     });
@@ -428,7 +428,7 @@ describe('FieldNode', () => {
       expect(f.a().disabledReasons()).toEqual([
         {
           field: f.a,
-          reason: 'a cannot be changed',
+          message: 'a cannot be changed',
         },
       ]);
     });
@@ -446,14 +446,37 @@ describe('FieldNode', () => {
       expect(f().disabledReasons()).toEqual([
         {
           field: f,
-          reason: 'form unavailable',
+          message: 'form unavailable',
         },
       ]);
       expect(f.a().disabled()).toBe(true);
       expect(f.a().disabledReasons()).toEqual([
         {
           field: f,
-          reason: 'form unavailable',
+          message: 'form unavailable',
+        },
+      ]);
+    });
+
+    it('should disable unconditionally', () => {
+      const f = form(
+        signal({a: '', b: ''}),
+        (p) => {
+          disabled(p.a);
+          disabled(p.b, 'disabled!');
+        },
+        {injector: TestBed.inject(Injector)},
+      );
+
+      expect(f.a().disabledReasons()).toEqual([
+        {
+          field: f.a,
+        },
+      ]);
+      expect(f.b().disabledReasons()).toEqual([
+        {
+          field: f.b,
+          message: 'disabled!',
         },
       ]);
     });

packages/forms/signals/test/web/control_directive.spec.ts

@@ -439,7 +439,7 @@ describe('control directive', () => {
     const comp = act(() => TestBed.createComponent(ReadonlyTestCmp)).componentInstance;
 
     expect(comp.myInput().disabledReasons()).toEqual([
-      {reason: 'Currently unavailable', field: comp.f},
+      {message: 'Currently unavailable', field: comp.f},
     ]);
   });