Add a failing type test for openapi-fetch

Author: illright

packages/openapi-fetch/test/index.test-d.ts

@@ -0,0 +1,66 @@
+import { test, expectTypeOf } from "vitest";
+
+import createClient from "../src/index.js";
+
+interface paths {
+  "/": {
+    get: operations["GetObjects"];
+  };
+}
+
+interface operations {
+  GetObjects: {
+    parameters: {};
+    responses: {
+      200: components["responses"]["MultipleObjectsResponse"];
+      401: components["responses"]["Unauthorized"];
+      422: components["responses"]["GenericError"];
+    };
+  };
+}
+
+interface components {
+  schemas: {
+    Object: {
+      id: string;
+      name: string;
+    };
+    GenericErrorModel: {
+      errors: {
+        body: string[];
+      };
+    };
+  };
+  responses: {
+    MultipleObjectsResponse: {
+      content: {
+        "application/json": {
+          objects: components["schemas"]["Object"][];
+        };
+      };
+    };
+    /** @description Unauthorized */
+    Unauthorized: {
+      content: {};
+    };
+    /** @description Unexpected error */
+    GenericError: {
+      content: {
+        "application/json": components["schemas"]["GenericErrorModel"];
+      };
+    };
+  };
+}
+
+const { GET } = createClient<paths>();
+
+test("the error type works properly", async () => {
+  const value = await GET("/");
+
+  if (value.data) {
+    expectTypeOf(value.data).toEqualTypeOf({ objects: [{ id: "", name: "" }] });
+  } else {
+    expectTypeOf(value.data).toBeUndefined();
+    expectTypeOf(value.error).toEqualTypeOf({ errors: [""] });
+  }
+});