fix(jit): exclude all Angular decorators from non-Angular __decorate lowering

Angular parameter decorators (@Inject, @optional, @self, @SkipSelf, @host,
@Attribute) and class decorators (@component, @directive, @pipe, @Injectable,
@NgModule) should never be emitted in member __decorate() calls. Previously
only the 8 field decorators were excluded; now all 19 Angular decorators are
excluded from the non-Angular member decorator extraction.

This matches Angular's official behavior where decorators are identified by
their @angular/core import source — any Angular decorator on a member should
be handled via propDecorators/ctorParameters, not __decorate.

https://claude.ai/code/session_01BbwLMsG3SjXcCbvDxAyW2Z

Author: ashh640

crates/oxc_angular_compiler/src/component/transform.rs

@@ -931,7 +931,13 @@ fn extract_non_angular_member_decorators(
 ) -> std::vec::Vec<JitNonAngularMemberDecorator> {
     use oxc_ast::ast::{ClassElement, MethodDefinitionKind, PropertyKey};
 
-    const ANGULAR_MEMBER_DECORATORS: &[&str] = &[
+    // All Angular decorators that should NOT be lowered via __decorate().
+    // This includes field decorators (handled via propDecorators), parameter decorators
+    // (handled via ctorParameters), and class decorators (handled via class __decorate).
+    // Angular identifies these by import source (@angular/core); we use names since
+    // they're unique enough and matches the official FIELD_DECORATORS list.
+    const ANGULAR_DECORATORS: &[&str] = &[
+        // Field decorators (go into propDecorators)
         "Input",
         "Output",
         "HostBinding",
@@ -940,6 +946,19 @@ fn extract_non_angular_member_decorators(
         "ViewChildren",
         "ContentChild",
         "ContentChildren",
+        // Parameter decorators (go into ctorParameters, but could appear on members)
+        "Inject",
+        "Optional",
+        "Self",
+        "SkipSelf",
+        "Host",
+        "Attribute",
+        // Class decorators (shouldn't appear on members, but exclude defensively)
+        "Component",
+        "Directive",
+        "Pipe",
+        "Injectable",
+        "NgModule",
     ];
 
     let mut result: std::vec::Vec<JitNonAngularMemberDecorator> = std::vec::Vec::new();
@@ -991,7 +1010,7 @@ fn extract_non_angular_member_decorators(
 
             let is_angular = dec_name
                 .as_ref()
-                .is_some_and(|n| ANGULAR_MEMBER_DECORATORS.contains(&n.as_str()));
+                .is_some_and(|n| ANGULAR_DECORATORS.contains(&n.as_str()));
 
             if !is_angular {
                 // Extract the decorator expression text from source (without the @)

crates/oxc_angular_compiler/tests/integration_test.rs

@@ -7039,6 +7039,58 @@ export class TestService {
     insta::assert_snapshot!("jit_complex_decorator_arguments", result.code);
 }
 
+#[test]
+fn test_jit_angular_param_decorators_not_in_member_decorate() {
+    // Angular parameter decorators (@Inject, @Optional, @Self, @SkipSelf, @Host, @Attribute)
+    // should NOT be emitted in __decorate() calls if they appear on a member.
+    // While these are designed for constructor params, if someone puts them on a member,
+    // they should be treated as Angular decorators (not lowered via __decorate).
+    let allocator = Allocator::default();
+    let source = r#"
+import { Injectable, Inject, Optional } from '@angular/core';
+
+function Custom() { return function(t: any, k: string) {}; }
+
+@Injectable()
+export class MyService {
+    @Inject('TOKEN')
+    token: any;
+
+    @Optional()
+    optionalDep: any;
+
+    @Custom()
+    customProp: string = '';
+}
+"#;
+
+    let options = ComponentTransformOptions { jit: true, ..Default::default() };
+    let result = transform_angular_file(&allocator, "my.service.ts", source, &options, None);
+    assert!(!result.has_errors(), "Should not have errors: {:?}", result.diagnostics);
+
+    // @Custom should be lowered via __decorate (it's non-Angular)
+    assert!(
+        result.code.contains("__decorate([Custom()], MyService.prototype, \"customProp\", void 0)"),
+        "Non-Angular decorator should be in __decorate. Got:\n{}",
+        result.code
+    );
+
+    // @Inject and @Optional should NOT appear in __decorate calls for members
+    // They are Angular decorators and should not be treated as non-Angular
+    let member_decorate_calls: Vec<&str> = result.code.lines()
+        .filter(|l| l.contains("__decorate(") && l.contains(".prototype"))
+        .collect();
+    for call in &member_decorate_calls {
+        assert!(
+            !call.contains("Inject(") && !call.contains("Optional()"),
+            "Angular param decorators should not appear in member __decorate calls. Got:\n{}",
+            call
+        );
+    }
+
+    insta::assert_snapshot!("jit_angular_param_decorators_on_members", result.code);
+}
+
 // =========================================================================
 // Reference output comparison tests
 // =========================================================================

crates/oxc_angular_compiler/tests/snapshots/integration_test__jit_angular_param_decorators_on_members.snap

@@ -0,0 +1,22 @@
+---
+source: crates/oxc_angular_compiler/tests/integration_test.rs
+expression: result.code
+---
+
+import { Injectable, Inject, Optional } from '@angular/core';
+import { __decorate } from "tslib";
+
+function Custom() { return function(t: any, k: string) {}; }
+
+let MyService = class MyService {
+    token: any;
+
+    optionalDep: any;
+
+    customProp: string = '';
+};
+__decorate([Custom()], MyService.prototype, "customProp", void 0);
+MyService = __decorate([
+    Injectable()
+], MyService);
+export { MyService };