Pass refkey to DataclassDeclaration (#334)

`DataclassDeclaration` doesn't forward the `refkey` prop to the
underlying `ClassDeclaration`, causing symbol resolution to fail when
other code tries to reference the dataclass, so we are fixing that.

Author: mauriciogardini

.chronus/changes/feature-dataclass-fix-2025-9-31-21-14-40.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@alloy-js/python"
+---
+
+Pass refkey to DataclassDeclaration

packages/python/src/components/DataclassDeclaration.tsx

@@ -176,7 +176,12 @@ export function DataclassDeclaration(props: DataclassDeclarationProps) {
         )
       </Show>
       <hbr />
-      <ClassDeclaration name={props.name} bases={props.bases} doc={props.doc}>
+      <ClassDeclaration
+        name={props.name}
+        bases={props.bases}
+        doc={props.doc}
+        refkey={props.refkey}
+      >
         <StatementList>{props.children}</StatementList>
         {validateDataclassMemberConflicts(kwargs as DataclassDecoratorKwargs)}
       </ClassDeclaration>

packages/python/test/dataclassdeclarations.test.tsx

@@ -1,9 +1,13 @@
-import { Prose, namekey } from "@alloy-js/core";
+import { Prose, namekey, refkey } from "@alloy-js/core";
 import { d } from "@alloy-js/core/testing";
 import { describe, expect, it } from "vitest";
 import { dataclassesModule } from "../src/builtins/python.js";
 import * as py from "../src/index.js";
-import { toSourceText } from "./utils.jsx";
+import {
+  assertFileContents,
+  toSourceText,
+  toSourceTextMultiple,
+} from "./utils.jsx";
 
 describe("DataclassDeclaration", () => {
   it("Creates a dataclass with a class doc", () => {
@@ -582,4 +586,61 @@ describe("DataclassDeclaration", () => {
       `,
     );
   });
+
+  it("Forwards refkey prop for symbol resolution in type references", () => {
+    const userRefkey = refkey();
+    const res = toSourceTextMultiple(
+      [
+        <py.SourceFile path="models.py">
+          <py.DataclassDeclaration name="User" refkey={userRefkey}>
+            <py.VariableDeclaration
+              instanceVariable
+              omitNone
+              name="id"
+              type="int"
+            />
+            <py.VariableDeclaration
+              instanceVariable
+              omitNone
+              name="name"
+              type="str"
+            />
+          </py.DataclassDeclaration>
+        </py.SourceFile>,
+        <py.SourceFile path="services.py">
+          <py.FunctionDeclaration name="get_user" returnType={userRefkey}>
+            <py.VariableDeclaration
+              name="user"
+              type={userRefkey}
+              initializer={
+                <py.ClassInstantiation target="User" args={["1", '"Alice"']} />
+              }
+            />
+            <hbr />
+            {"return user"}
+          </py.FunctionDeclaration>
+        </py.SourceFile>,
+      ],
+      { externals: [dataclassesModule] },
+    );
+    assertFileContents(res, {
+      "models.py": `
+        from dataclasses import dataclass
+
+        @dataclass
+        class User:
+            id: int
+            name: str
+
+        `,
+      "services.py": `
+        from models import User
+
+        def get_user() -> User:
+            user: User = User(1, "Alice")
+            return user
+
+        `,
+    });
+  });
 });