fix(isolated-declarations): should print constructor assignments first (#5934)

crates/oxc_isolated_declarations/src/class.rs

@@ -402,7 +402,8 @@ impl<'a> IsolatedDeclarations<'a> {
                     };
 
                     if let MethodDefinitionKind::Constructor = method.kind {
-                        elements.extend(
+                        elements.splice(
+                            0..0,
                             self.transform_constructor_params_to_class_properties(
                                 function, &params,
                             ),

crates/oxc_isolated_declarations/tests/fixtures/class.ts

@@ -49,3 +49,8 @@ export class Bux {
     readonly prop3: number = 1,
   ) {}
 }
+
+export class PrivateFieldsWithConstructorAssignments {
+  private second = 0;
+  constructor(public first: number) {}
+}

crates/oxc_isolated_declarations/tests/snapshots/class.snap

@@ -46,3 +46,8 @@ export declare class Bux {
 	readonly prop3: number;
 	private constructor();
 }
+export declare class PrivateFieldsWithConstructorAssignments {
+	first: number;
+	private second;
+	constructor(first: number);
+}