angular/packages/forms/signals/test/node/api/hidden.spec.ts
Miles Malerba b8314bd340 feat(forms): add experimental signal-based forms (#63408)
This commit introduces an experimental version of a new signal-based forms API for Angular. This new API aims to explore how signals can be leveraged to create a more declarative, intuitive, and reactive way of handling forms.

The primary goals of this new signal-based approach are:

*   **Signal-centric Design:** Place signals at the core of the forms experience, enabling a truly reactive programming model for form state and logic.
*   **Declarative Logic:** Allow developers to define form behavior, such as validation and conditional fields, declaratively using TypeScript. This moves logic out of the template and into a typed, testable schema.
*   **Developer-Owned Data Model:** The library does not maintain a copy of data in a form model, but instead read and write it via a developer-provided `WritableSignal`, eliminating the need for applications to synchronize their data with the form system.
*   **Interoperability:** A key design goal is seamless interoperability with existing reactive forms, allowing for incremental adoption.
*   **Bridging Template and Reactive Forms:** This exploration hopes to close the gap between template and reactive forms, offering a unified and more powerful approach that combines the best aspects of both.

This initial version of the experimental API includes the core building blocks, such as the `form()` function, `Field` and `FieldState` objects, and a `[control]` directive for binding to UI elements. It also introduces a schema-based system for defining validation, conditional logic, and other form behaviors.

Note: This is an early, experimental API. It is not yet complete and is subject to change based on feedback and further exploration.

Co-authored-by: Kirill Cherkashin <kirts@google.com>
Co-authored-by: Alex Rickabaugh <alxhub@users.noreply.github.com>
Co-authored-by: Leon Senft <leonsenft@users.noreply.github.com>
Co-authored-by: Dylan Hunn <dylhunn@gmail.com>
Co-authored-by: Michael Small <michael-small@users.noreply.github.com>

PR Close #63408
2025-08-28 09:02:43 -07:00

118 lines
3.2 KiB
TypeScript

/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.dev/license
*/
import {Injector, signal} from '@angular/core';
import {form, hidden, validate, customError} from '@angular/forms/signals';
import {TestBed} from '@angular/core/testing';
describe('hidden', () => {
it('should initially be false', () => {
const cat = signal({name: 'Pirojok-the-cat', age: 5});
const f = form(
cat,
(p) => {
hidden(p, ({value}) => {
return value.name === 'hidden-cat';
});
},
{injector: TestBed.inject(Injector)},
);
expect(f().hidden()).toBe(false);
expect(f.name().hidden()).toBe(false);
});
it('returns true when condition is met', () => {
const cat = signal({name: 'Pirojok-the-cat', age: 5});
const f = form(
cat,
(p) => {
hidden(p.name, ({value}) => {
return value() === 'hidden-cat';
});
},
{injector: TestBed.inject(Injector)},
);
f.name().value.set('hidden-cat');
expect(f.name().hidden()).toBe(true);
});
it('propagates the value down', () => {
const cat = signal({name: 'Pirojok-the-cat', age: 5});
const f = form(
cat,
(p) => {
hidden(p, ({value}) => {
return value().name === 'hidden-cat';
});
},
{injector: TestBed.inject(Injector)},
);
f.name().value.set('hidden-cat');
expect(f.name().hidden()).toBe(true);
expect(f().hidden()).toBe(true);
});
it('disables validation for the field', () => {
const cat = signal({name: 'Pirojok-the-cat', age: 5});
const f = form(
cat,
(p) => {
hidden(p.name, ({value}) => {
return value() === 'hidden-cat';
});
validate(p.name, () => {
return customError({kind: 'dog'});
});
},
{injector: TestBed.inject(Injector)},
);
expect(f.name().valid()).withContext('Name is intially invalid').toBeFalse();
expect(f().valid()).withContext('Form is intially invalid').toBeFalse();
f.name().value.set('hidden-cat');
expect(f.name().hidden()).toBeTrue();
expect(f.name().valid()).toBeTrue();
expect(f().valid()).toBeTrue();
f.name().value.set('visible-cat');
expect(f.name().valid()).toBeFalse();
expect(f().valid()).toBeFalse();
});
xit('disables touch state propagation?', () => {
const cat = signal({name: 'Pirojok-the-cat', age: 5});
const f = form(
cat,
(p) => {
hidden(p.name, ({value}) => {
return value() === 'hidden-cat';
});
},
{injector: TestBed.inject(Injector)},
);
expect(f.name().touched()).withContext('Name is intially untouched').toBeFalse();
expect(f().touched()).withContext('Form is intially intouched').toBeFalse();
f.name().markAsTouched();
expect(f.name().touched()).toBeTrue();
expect(f().touched()).toBeTrue();
f.name().value.set('hidden-cat');
expect(f.name().touched()).withContext('hidden name is not touched').toBeFalse();
expect(f().touched())
.withContext('form with a hidden touched field is not touched')
.toBeFalse();
});
});