fix: answer DOM probes on NativeScriptDocument instead of throwing - #176

What

Angular discovers some optional configuration by reading the DOM. NativeScriptDocument exposed a body that was truthy but hollow ({ isOverride: true }), so those probes did not fall into their "not found" path — they threw.

The clearest case is CSP_NONCE, whose default factory is:

inject(DOCUMENT).body?.querySelector('[ngCspNonce]')?.getAttribute('ngCspNonce') || null

The body?. guard anticipates a missing body, not a body without querySelector, so this fails with inject(...).body?.querySelector is not a function.

Signal forms hit this on the very first [formField] binding: FormField injects the root InputValidityMonitor, whose default implementation (AnimationInputValidityMonitor) injects CSP_NONCE in a field initializer. The result is that every signal-form dialog crashes at construction on Angular 22. Note that inject(CSP_NONCE, { optional: true }) does not help — InjectionToken defaults to providedIn: 'root', so the token always resolves and the DOM-reading factory always runs.

Changes

• NativeScriptDocument now answers DOM lookups with "nothing found" rather than leaving the methods undefined: querySelector, querySelectorAll, getElementById, getElementsByTagName, getElementsByClassName on the document itself, plus body and head (getAttribute/hasAttribute included there).
• createElement deliberately keeps throwing. Probing for optional config should degrade quietly; constructing real nodes is a caller bug and should stay loud.
• CSP_NONCE is provided as null in NATIVESCRIPT_MODULE_STATIC_PROVIDERS. There is no CSP in a NativeScript runtime, and providing it skips the DOM-reading factory entirely.

Why CSP_NONCE must be a root provider

It is deliberately in NATIVESCRIPT_MODULE_STATIC_PROVIDERS (root scope) rather than COMMON_PROVIDERS (platform scope). R3Injector.get() checks its own records, then self-instantiates any providedIn: 'root' token whose scope it matches, and only then delegates to its parent. A platform-level provider is therefore never consulted. Verified empirically — see below.

Verification

Ran Angular 22's real DI against both the old and new document shapes:

The first row reproduces the reported crash string exactly.

nx build angular passes, and packages/angular/src/lib/platform-nativescript.ts is prettier-clean. nativescript.ts has pre-existing formatting drift that I left alone to keep the diff focused.

Follow-up

This is the robust workaround. The cleaner fix belongs upstream: InputValidityMonitor is an abstract class whose provider is { providedIn: 'root', useClass: forwardRef(() => AnimationInputValidityMonitor) } — an obvious platform seam that Angular's own tests already override — but the symbol is not exported. I have a companion Angular PR adding ɵInputValidityMonitor to @angular/forms/signals. Once that lands, @nativescript/angular can provide an inert monitor and never touch the DOM at all.