fix(directive): @Input({transform: window ? atob : btoa}) / atob || btoa reports a false "must be a function" #517

ngtsc evaluates ambient globals (from lib.dom.d.ts) as references, which count as truthy. So window ? atob : btoa and atob || btoa resolve to atob. OXC treats the globals as unknown values, so the transform stays dynamic. The transform validation added in #494 then reports an error.

Repro

import {Directive, Input} from '@angular/core';
@Directive({selector: '[d]'})
export class D { @Input({transform: window ? atob : btoa}) a: any; }

(same with transform: atob || btoa)

OXC #504 tip

Error: Input transform must be a function Value could not be determined statically.

OXC main

No error. The expression is emitted as written: inputs:{a:[2,"a","a",(window? atob: btoa)]} ((atob || btoa)). This works at runtime but doesn't match ngtsc.

ngtsc 22.1.7

inputs: { a: [2, "a", "a", atob] }

Where

crates/oxc_angular_compiler/src/directive/evaluator.rs at the #504 tip. The global identifier evaluates to Value::Dynamic. The transform check (~L2640, added by #494 feat/validate-input-transforms, commit 58b12f7) then reports "must be a function".

In ngtsc, partial_evaluator/src/interpreter.ts turns a declared-only variable (isVariableDeclarationDeclared, e.g. declare var window in lib.dom) into a Reference. A Reference is truthy, so visitConditionalExpression and || take the atob branch.

On main?

No. This false error comes with #494. Main has no check here.

Direction

Either treat a known ambient global identifier (one not declared in the file) as a truthy opaque reference for ?:, ||, && and ??, as ngtsc does. Or, more simply, don't report "must be a function" when the dynamic part is only a global, and emit the expression as main does.