Fix native generation overwriting empty shared model files

native/src/render.rs

@@ -77,7 +77,10 @@ pub fn render_model_proxies(
         let (proxies, proxies_elapsed) = proxies.join().unwrap();
         (common, proxies, common_elapsed, proxies_elapsed)
     });
-    rendered.insert(options.default_tag.clone(), Value::String(common));
+    // Match JavaScript: an empty schema collection emits no shared model file.
+    if !schemas.is_empty() {
+        rendered.insert(options.default_tag.clone(), Value::String(common));
+    }
     rendered.extend(proxies);
     if std::env::var_os("OPENAPI_NATIVE_PROFILE").is_some() {
         eprintln!(

scripts/renderer-parity-cases.ts

@@ -1,10 +1,25 @@
-import { parse } from "yaml";
+import { readFileSync } from "node:fs";
+import { parse, stringify } from "yaml";
 import { resolveConfig } from "../src/generators/core/resolveConfig";
 import { generateCodeFromOpenAPIDoc } from "../src/generators/generateCodeFromOpenAPIDoc";
 import { generateFilesFromNativeOpenAPI } from "../src/native/generateFilesFromNativeOpenAPI";
 import { type ParityScenario } from "./renderer-parity-configs";
 
-export const parityFixtures = ["test/petstore.yaml", "test/configuration.yaml"];
+export const parityFixtures = [
+  { name: "petstore", file: "test/petstore.yaml" },
+  { name: "configuration", file: "test/configuration.yaml" },
+  { name: "petstore-health", file: "test/petstore.yaml", healthOnly: true },
+];
+
+export function readParityFixture(fixture: (typeof parityFixtures)[number]) {
+  const source = readFileSync(fixture.file, "utf8");
+  if (!fixture.healthOnly) return source;
+  const document = parse(source);
+  const health = document.paths["/health"];
+  if (!health) throw new Error("Petstore health parity endpoint is missing");
+  // A schema-free Petstore slice exercises omission across every configuration.
+  return stringify({ ...document, paths: { "/health": health }, components: {} });
+}
 
 export function renderParityCase(source: string, scenario: ParityScenario, renderer: "js" | "native") {
   let options;

scripts/renderer-parity.ts

@@ -2,7 +2,7 @@ import { createHash } from "node:crypto";
 import { mkdir, readFile, writeFile } from "node:fs/promises";
 import path from "node:path";
 import { parityScenarios } from "./renderer-parity-configs";
-import { parityFixtures, renderParityCase } from "./renderer-parity-cases";
+import { parityFixtures, readParityFixture, renderParityCase } from "./renderer-parity-cases";
 
 export type Manifest = Record<string, string>;
 
@@ -36,9 +36,9 @@ async function generate(renderer: string, output: string) {
   const manifest: Manifest = {};
   const routes: Record<string, string> = {};
   for (const fixture of parityFixtures) {
-    const source = await readFile(fixture, "utf8");
+    const source = readParityFixture(fixture);
     for (const scenario of parityScenarios) {
-      const prefix = `${path.basename(fixture, ".yaml")}/${scenario.name}`;
+      const prefix = `${fixture.name}/${scenario.name}`;
       const { files, route } = renderParityCase(source, scenario, renderer);
       routes[prefix] = route;
       // Include even deliberately empty and rejected cases in the hash contract.

src/generators/core/endpoints/getEndpointsFromOpenAPIDoc.test.ts

@@ -898,6 +898,21 @@ describe("getEndpointsFromOpenAPIDoc", () => {
     const resolver = new SchemaResolver(openApiDoc, generateOptions);
     const endpoints = getEndpointsFromOpenAPIDoc(resolver);
     expect(endpoints).toEqual([
+      {
+        description: undefined,
+        summary: "No-model response for empty shared model parity coverage",
+        errors: [],
+        method: "get",
+        operationName: "getHealth",
+        parameters: [],
+        path: "/health",
+        tags: ["Health"],
+        mediaDownload: false,
+        mediaUpload: false,
+        requestFormat: "application/json",
+        response: "z.void()",
+        responseStatusCodes: ["204"],
+      },
       ...[
         ["EmailAdmin", "email", "EmailActivityAdminResponse"],
         ["PushNotificationAdmin", "push", "PushNotificationActivityAdminResponse"],

src/generators/core/getMetadataFromOpenAPIDoc.test.ts

@@ -247,6 +247,15 @@ describe("getMetadataFromOpenAPIDoc", () => {
   ];
 
   const queries: QueryMetadata[] = [
+    {
+      name: "useGet",
+      namespace: "HealthQueries",
+      importPath: "health/health.queries",
+      isMutation: false,
+      isQuery: true,
+      params: [],
+      response: { metaType: "primitive", type: "void" },
+    },
     {
       name: "useReadActivity",
       importPath: "emailAdmin/emailAdmin.queries",

src/native/configuration-lifecycle.test.ts

@@ -1,4 +1,4 @@
-import { mkdtemp, readFile, rm, stat, utimes, writeFile } from "node:fs/promises";
+import { mkdir, mkdtemp, readFile, rm, stat, utimes, writeFile } from "node:fs/promises";
 import os from "node:os";
 import path from "node:path";
 import { stringify } from "yaml";
@@ -87,3 +87,72 @@ describe("configuration input and output lifecycle", () => {
     }
   });
 });
+
+describe("empty shared models", () => {
+  test.each(cases.flatMap((entry) => [false, true].map((modelsOnly) => ({ ...entry, modelsOnly }))))(
+    "$renderer / $format / incremental=$incremental / modelsOnly=$modelsOnly preserves shared enums",
+    async ({ renderer, format, incremental, modelsOnly }) => {
+      const directory = await mkdtemp(path.join(os.tmpdir(), "codegen-empty-models-"));
+      const input = path.join(directory, `schema.${format}`);
+      const output = path.join(directory, "output");
+      const common = path.join(output, "common/common.models.ts");
+      const previousNative = process.env.OPENAPI_CODEGEN_NATIVE;
+      const previousRequired = process.env.OPENAPI_CODEGEN_REQUIRE_FULL_NATIVE;
+      process.env.OPENAPI_CODEGEN_NATIVE = renderer === "native" ? "1" : "0";
+      process.env.OPENAPI_CODEGEN_REQUIRE_FULL_NATIVE = "1";
+      try {
+        const document = {
+          openapi: "3.0.3",
+          info: { title: "No models", version: "1" },
+          paths: {
+            "/health": {
+              get: {
+                operationId: "health",
+                tags: ["health"],
+                responses: { "204": { description: "OK" } },
+              },
+            },
+          },
+        };
+        await writeFile(input, format === "json" ? JSON.stringify(document) : stringify(document));
+        const generate = (clearOutput = false) =>
+          runGenerate({
+            fileConfig: {
+              input,
+              output,
+              clearOutput,
+              incremental,
+              modelsOnly,
+              modelsInCommon: true,
+              acl: false,
+              mutationEffects: false,
+              restClientImportPath: "@test/rest",
+            },
+          });
+        await generate();
+        await expect(stat(common)).rejects.toMatchObject({ code: "ENOENT" });
+        if (!modelsOnly) {
+          expect(await readFile(path.join(output, "health/health.api.ts"), "utf8")).toContain("/health");
+        }
+        await mkdir(path.dirname(common), { recursive: true });
+        const existing = 'export enum Status { Ready = "ready" }\n';
+        await writeFile(common, existing);
+        const sentinel = new Date("2001-01-01T00:00:00Z");
+        await utimes(common, sentinel, sentinel);
+        const before = (await stat(common)).mtimeMs;
+        await generate();
+        expect(await readFile(common, "utf8")).toBe(existing);
+        expect((await stat(common)).mtimeMs).toBe(before);
+        // Explicit cleanup removes stale generated models, rather than replacing them with an empty module.
+        await generate(true);
+        await expect(stat(common)).rejects.toMatchObject({ code: "ENOENT" });
+      } finally {
+        if (previousNative === undefined) delete process.env.OPENAPI_CODEGEN_NATIVE;
+        else process.env.OPENAPI_CODEGEN_NATIVE = previousNative;
+        if (previousRequired === undefined) delete process.env.OPENAPI_CODEGEN_REQUIRE_FULL_NATIVE;
+        else process.env.OPENAPI_CODEGEN_REQUIRE_FULL_NATIVE = previousRequired;
+        await rm(directory, { recursive: true, force: true });
+      }
+    },
+  );
+});

src/native/configuration-parity.test.ts

@@ -2,7 +2,7 @@ import { parse, stringify } from "yaml";
 import { readFileSync } from "node:fs";
 import { afterEach, describe, expect, test, vi } from "vitest";
 import { parityScenarios, optionCases, lifecycleOptions } from "../../scripts/renderer-parity-configs";
-import { parityFixtures, renderParityCase } from "../../scripts/renderer-parity-cases";
+import { parityFixtures, readParityFixture, renderParityCase } from "../../scripts/renderer-parity-cases";
 import { getNativeBindings } from "./native-bindings";
 
 afterEach(() => {
@@ -22,8 +22,8 @@ describe("configuration coverage inventory", () => {
 });
 
 for (const fixture of parityFixtures) {
-  const source = readFileSync(fixture, "utf8");
-  describe(`all renderer configurations: ${fixture}`, () => {
+  const source = readParityFixture(fixture);
+  describe(`all renderer configurations: ${fixture.name}`, () => {
     test.each(parityScenarios)("$name", (scenario) => {
       vi.stubEnv("OPENAPI_CODEGEN_NATIVE", "1");
       const binding = vi.spyOn(getNativeBindings(), "compileData");
@@ -44,7 +44,7 @@ for (const fixture of parityFixtures) {
 
 test("canonical layouts retain full native rendering and local namespaces use native hybrid", () => {
   vi.stubEnv("OPENAPI_CODEGEN_NATIVE", "1");
-  const source = readFileSync(parityFixtures[0], "utf8");
+  const source = readParityFixture(parityFixtures[0]);
   for (const [tsNamespaces, modelsInCommon] of [
     [true, true],
     [false, false],
@@ -117,3 +117,20 @@ test("model owner resolution preserves model-like text inside validation regexes
   expect(api(expected.files)).toContain(".regex(/EmailAdminModels.BaseLogLevelEnumSchema/)");
   expect(api(actual.files)).toBe(api(expected.files));
 });
+
+test.each([false, true])("Petstore empty shared model scenario is active with modelsOnly=%s", (modelsOnly) => {
+  const source = readParityFixture(parityFixtures.find((fixture) => fixture.name === "petstore-health")!);
+  const scenario = parityScenarios.find((entry) => entry.name === `layout-${modelsOnly ? "010111" : "000111"}`)!;
+  expect(scenario).toBeDefined();
+  for (const renderer of ["js", "native"] as const) {
+    vi.stubEnv("OPENAPI_CODEGEN_NATIVE", renderer === "native" ? "1" : "0");
+    const result = renderParityCase(source, scenario, renderer);
+    expect(result.route).toBe(renderer === "native" ? "full-native" : "js");
+    expect(result.files.some((file) => file.fileName.endsWith("common.models.ts"))).toBe(false);
+    if (modelsOnly) {
+      expect(result.files.every((file) => file.fileName.endsWith(".models.ts"))).toBe(true);
+    } else {
+      expect(result.files.find((file) => file.fileName.endsWith("health.api.ts"))?.content).toContain("/health");
+    }
+  }
+});

test/petstore.yaml

@@ -38,6 +38,14 @@ tags:
   - name: user
     description: Operations about user
 paths:
+  /health:
+    get:
+      tags: [Health]
+      summary: No-model response for empty shared model parity coverage
+      operationId: getHealth
+      responses:
+        "204":
+          description: Healthy
   /activity/email:
     get:
       tags: [EmailAdmin]