diff --git a/crates/oxc_angular_compiler/src/class_metadata/builders.rs b/crates/oxc_angular_compiler/src/class_metadata/builders.rs
index 9fd329465..fa75acae7 100644
--- a/crates/oxc_angular_compiler/src/class_metadata/builders.rs
+++ b/crates/oxc_angular_compiler/src/class_metadata/builders.rs
@@ -589,7 +589,16 @@ pub fn build_prop_decorators_metadata_in<'a>(
             })
             .collect();
 
-        if !angular_decorators.is_empty() {
+        // ngtsc lists any member that carries decorators — even when none
+        // of them are Angular's — as `prop: []` (`decoratedClassMemberTo-
+        // Metadata` filters to Angular decorators, but the member entry is
+        // unconditional on `member.decorators.length > 0`, metadata.ts:107).
+        // `member.decorators` is already filtered by the reflection host:
+        // `_reflectDecorator` drops a decorator whose callee isn't an
+        // identifier or `ns.Name` access (`isDecoratorIdentifier`), so an
+        // `@a.b.Foo()` or `@(a.Foo)()` member counts as undecorated and
+        // reaches the initializer-API synthesis below.
+        if decorators.iter().any(is_reflectable_decorator) {
             // Build decorators array from the real decorators present in source.
             let decorators_array = build_decorator_metadata_array(
                 &allocator,
@@ -1028,6 +1037,24 @@ fn extract_angular_decorators_from_param<'a, 'b>(
         .collect()
 }
 
+/// Whether ngtsc's reflection host keeps `decorator` in `member.decorators`:
+/// `_reflectDecorator` returns `null` unless the (possibly called) decorator
+/// expression is an identifier or `ns.Name` property access
+/// (`isDecoratorIdentifier`). `@decs['Foo']()` or `@a.b.Foo()` don't reflect.
+fn is_reflectable_decorator(decorator: &Decorator<'_>) -> bool {
+    let expr = match &decorator.expression {
+        Expression::CallExpression(call) => &call.callee,
+        expr => expr,
+    };
+    match expr {
+        Expression::Identifier(_) => true,
+        Expression::StaticMemberExpression(m) => {
+            matches!(&m.object, Expression::Identifier(_))
+        }
+        _ => false,
+    }
+}
+
 /// Get the name of a decorator.
 fn get_decorator_name<'a>(decorator: &Decorator<'a>) -> Option<&'a str> {
     match &decorator.expression {
diff --git a/crates/oxc_angular_compiler/src/output/oxc_converter.rs b/crates/oxc_angular_compiler/src/output/oxc_converter.rs
index 6849c6785..fa72e7dd6 100644
--- a/crates/oxc_angular_compiler/src/output/oxc_converter.rs
+++ b/crates/oxc_angular_compiler/src/output/oxc_converter.rs
@@ -399,9 +399,12 @@ fn convert_call_expression_with_optional<'a>(
     for arg in &call.arguments {
         match arg {
             Argument::SpreadElement(spread) => {
-                // Handle spread arguments
+                // Keep the spread — `f(...P)` is not `f(P)` (issue #511).
                 let expr = convert_oxc_expression(allocator, &spread.argument, source_text)?;
-                args.push(expr);
+                args.push(OutputExpression::SpreadElement(Box::new_in(
+                    SpreadElementExpr { expr: Box::new_in(expr, &allocator), source_span: None },
+                    &allocator,
+                )));
             }
             _ => {
                 let expr = arg.to_expression();
@@ -437,8 +440,12 @@ fn convert_new_expression<'a>(
     for arg in &new_expr.arguments {
         match arg {
             Argument::SpreadElement(spread) => {
+                // Keep the spread — `new X(...P)` is not `new X(P)` (#511).
                 let expr = convert_oxc_expression(allocator, &spread.argument, source_text)?;
-                args.push(expr);
+                args.push(OutputExpression::SpreadElement(Box::new_in(
+                    SpreadElementExpr { expr: Box::new_in(expr, &allocator), source_span: None },
+                    &allocator,
+                )));
             }
             _ => {
                 let expr = arg.to_expression();
diff --git a/crates/oxc_angular_compiler/tests/decorator_metadata_ngtsc_test.rs b/crates/oxc_angular_compiler/tests/decorator_metadata_ngtsc_test.rs
index 336c212f0..bebc43527 100644
--- a/crates/oxc_angular_compiler/tests/decorator_metadata_ngtsc_test.rs
+++ b/crates/oxc_angular_compiler/tests/decorator_metadata_ngtsc_test.rs
@@ -1327,7 +1327,9 @@ export class Cmp {{
 /// `@angular/core`, under any alias or through a namespace import. Only those
 /// are compiled (the snapshot's `memberDecorator-*` probes), removed from the
 /// class and listed in `setClassMetadata`. Another module's `@Input` is left on
-/// the class and its options aren't checked, as ngtsc 22.1.7 does.
+/// the class and its options aren't checked, as ngtsc 22.1.7 does. Such
+/// foreign-decorated members still get a `propDecorators` entry — with an
+/// empty array, since none of their decorators are Angular's (issue #511).
 #[test]
 fn only_angular_member_decorators_are_compiled_and_removed() {
     let source = "import {Directive, Input as In} from '@angular/core';
@@ -1348,7 +1350,7 @@ export class Dir {
     assert!(code.contains("@Input({transform:5})c:any;"), "{}", result.code);
     assert!(code.contains("@HostListener('click')d(){}"), "{}", result.code);
     assert!(code.contains(r#"inputs:{a:"a"},outputs:{b:"b"}}"#), "{}", result.code);
-    assert!(code.contains("{a:[{type:In}],b:[{type:core.Output}]}"), "{}", result.code);
+    assert!(code.contains("{a:[{type:In}],b:[{type:core.Output}],c:[],d:[]}"), "{}", result.code);
 }
 
 /// A query predicate that isn't statically evaluable is emitted as written
diff --git a/crates/oxc_angular_compiler/tests/integration_test.rs b/crates/oxc_angular_compiler/tests/integration_test.rs
index 4ebb87438..a7e8b3532 100644
--- a/crates/oxc_angular_compiler/tests/integration_test.rs
+++ b/crates/oxc_angular_compiler/tests/integration_test.rs
@@ -9430,7 +9430,10 @@ export class TestComponent {
     let compact: String = result.code.chars().filter(|c| !c.is_whitespace()).collect();
 
     // propDecorators: any @angular/core member decorator counts, even
-    // @Component(); the foreign one doesn't.
+    // @Component(). The member entry is unconditional on having decorators
+    // (metadata.ts:107 `member.decorators.length > 0`), so the foreign
+    // decorator yields `foreignMember: []` — filtered to no Angular
+    // decorators — same as the ctorParameters `decorators: []` below (#511).
     assert!(
         compact.contains("componentMember:[{type:Component}]"),
         "@Component() member should be in propDecorators. Got:\n{}",
@@ -9442,8 +9445,8 @@ export class TestComponent {
         result.code
     );
     assert!(
-        !compact.contains("foreignMember:["),
-        "foreign-decorated member should not be in propDecorators. Got:\n{}",
+        compact.contains("foreignMember:[]"),
+        "foreign-decorated member should get an empty propDecorators entry. Got:\n{}",
         result.code
     );
 
diff --git a/crates/oxc_angular_compiler/tests/snapshots/integration_test__class_metadata_angular_core_decorators.snap b/crates/oxc_angular_compiler/tests/snapshots/integration_test__class_metadata_angular_core_decorators.snap
index 8b3dccab4..0ba00e95e 100644
--- a/crates/oxc_angular_compiler/tests/snapshots/integration_test__class_metadata_angular_core_decorators.snap
+++ b/crates/oxc_angular_compiler/tests/snapshots/integration_test__class_metadata_angular_core_decorators.snap
@@ -2,7 +2,6 @@
 source: crates/oxc_angular_compiler/tests/integration_test.rs
 expression: result.code
 ---
-
 import { Component, Inject, Injectable } from '@angular/core';
 import { Inject as ForeignInject } from 'not-angular';
 import * as i0 from '@angular/core';
@@ -42,5 +41,5 @@ static ɵcmp = /*@__PURE__*/ i0.ɵɵdefineComponent({type:TestComponent,selector
       [{type:Component,args:[{selector:"app-test",template:""}]}],() =>[{type:undefined,
           decorators:[{type:Inject,args:[TOKEN]}]},{type:undefined,decorators:[{type:Injectable}]},
           {type:undefined,decorators:[]}],{componentMember:[{type:Component}],knownMember:[{type:Inject,
-          args:[TOKEN]}]}));
+          args:[TOKEN]}],foreignMember:[]}));
 })();
diff --git a/crates/oxc_angular_compiler/tests/spread_metadata_emit_test.rs b/crates/oxc_angular_compiler/tests/spread_metadata_emit_test.rs
new file mode 100644
index 000000000..ac80d886e
--- /dev/null
+++ b/crates/oxc_angular_compiler/tests/spread_metadata_emit_test.rs
@@ -0,0 +1,136 @@
+//! Spread arguments in decorator metadata must be preserved (issue #511):
+//! `f(...P)` is not `f(P)`, and `new Box(...P)` is not `new Box(P)`.
+//! Plus the propDecorators shape rule from the same issue: a member whose
+//! decorators are all non-Angular still gets an entry (`x: []`).
+
+use oxc_allocator::Allocator;
+use oxc_angular_compiler::{CompilationMode, TransformOptions, transform_angular_file};
+
+fn compile(source: &str, mode: CompilationMode) -> String {
+    let allocator = Allocator::default();
+    let options = TransformOptions { compilation_mode: mode, ..Default::default() };
+    let result = transform_angular_file(&allocator, "test.ts", source, Some(&options), None);
+    assert!(!result.has_errors(), "should not have errors, got: {:?}", result.diagnostics);
+    // Whitespace-insensitive comparisons.
+    result.code.chars().filter(|c| !c.is_whitespace()).collect()
+}
+
+const SPREAD_SOURCE: &str = "import { Component } from '@angular/core';
+const P: any[] = [];
+function f(...a: any[]) { return a; }
+class Box { constructor(...a: any[]) {} }
+@Component({ selector: 'c', template: '', providers: f(...P) })
+export class C {}
+@Component({
+  selector: 'c2',
+  template: '',
+  providers: [{ provide: 'T', useValue: new Box(...P) }, ...P],
+})
+export class C2 {}
+";
+
+#[test]
+fn full_mode_call_spread_preserved() {
+    let code = compile(SPREAD_SOURCE, CompilationMode::Full);
+    assert!(
+        code.contains("ProvidersFeature(f(...P))"),
+        "providers call spread must survive, got:\n{code}"
+    );
+    assert!(
+        code.contains(r#"providers:f(...P)"#),
+        "setClassMetadata call spread must survive, got:\n{code}"
+    );
+}
+
+#[test]
+fn full_mode_new_spread_preserved() {
+    let code = compile(SPREAD_SOURCE, CompilationMode::Full);
+    assert!(
+        code.contains("useValue:newBox(...P)"),
+        "new-expression spread must survive, got:\n{code}"
+    );
+    assert!(code.contains(",...P]"), "array spread in providers must survive, got:\n{code}");
+}
+
+#[test]
+fn partial_mode_call_and_new_spread_preserved() {
+    let code = compile(SPREAD_SOURCE, CompilationMode::Partial);
+    assert!(
+        code.contains(r#"providers:f(...P)"#),
+        "ngDeclareComponent providers call spread must survive, got:\n{code}"
+    );
+    assert!(
+        code.contains("useValue:newBox(...P)},...P]"),
+        "ngDeclareComponent new-expression + array spread must survive, got:\n{code}"
+    );
+}
+
+/// ngtsc lists a member in `propDecorators` whenever it carries decorators,
+/// even when none of them are Angular's — `@Foo() x` emits `x: []`
+/// (metadata.ts:107 + decoratedClassMemberToMetadata).
+#[test]
+fn member_with_only_non_angular_decorators_gets_empty_entry() {
+    let source = "import { Component, Input } from '@angular/core';
+function Foo(): PropertyDecorator { return () => {}; }
+@Component({ selector: 'c', template: '' })
+export class C {
+  @Foo() x: any;
+  @Input() y: any;
+}
+";
+    let code = compile(source, CompilationMode::Full);
+    assert!(
+        code.contains("x:[]") || code.contains("\"x\":[]"),
+        "non-Angular-decorated member must emit an empty propDecorators entry, got:\n{code}"
+    );
+    assert!(
+        code.contains("y:[{type:Input}]") || code.contains("\"y\":[{type:Input}]"),
+        "Angular-decorated member must keep its entry, got:\n{code}"
+    );
+}
+
+/// A member with a non-Angular decorator AND a signal initializer still
+/// emits `x: []` — upstream runs the decorated-member branch, not the
+/// undecorated-metadata extractor.
+#[test]
+fn decorated_signal_member_emits_empty_entry() {
+    let source = "import { Component, Input, input } from '@angular/core';
+function Foo(): PropertyDecorator { return () => {}; }
+@Component({ selector: 'c', template: '' })
+export class C {
+  @Foo() x = input<string>('');
+  @Input() y: any;
+}
+";
+    let code = compile(source, CompilationMode::Full);
+    assert!(
+        code.contains("x:[]") || code.contains("\"x\":[]"),
+        "decorated signal member must emit `x: []`, got:\n{code}"
+    );
+}
+
+/// A decorator whose callee isn't an identifier or `ns.Name` access never
+/// reaches `member.decorators` upstream — `_reflectDecorator` returns null
+/// for `@a.b.Foo()` (the property-access object must be an identifier) or
+/// `@decs['Foo']()` (`isDecoratorIdentifier`). The member counts as
+/// undecorated, so its `input()` initializer gets the synthesized `Input`
+/// entry, not `x: []`.
+#[test]
+fn unreflectable_decorator_leaves_signal_member_on_initializer_path() {
+    let source = "import { Component, input } from '@angular/core';
+const a: any = {};
+@Component({ selector: 'c', template: '' })
+export class C {
+  @a.b.Foo() x = input<string>('');
+}
+";
+    let code = compile(source, CompilationMode::Full);
+    assert!(
+        code.contains("x:[{type:i0.Input"),
+        "unreflectable-decorated signal member must emit the synthesized Input entry, got:\n{code}"
+    );
+    assert!(
+        !code.contains("x:[]"),
+        "unreflectable decorator must not produce an empty entry, got:\n{code}"
+    );
+}