fix(openapi-fetch): treat default response as error (openapi-ts#1139)

Author: drwpow

README.md

@@ -129,6 +129,7 @@ All methods return an object with **data**, **error**, and **response**.
 
 - **data** will contain that endpoint’s `2xx` response if the server returned `2xx`; otherwise it will be `undefined`
 - **error** likewise contains that endpoint’s `4xx`/`5xx` response if the server returned either; otherwise it will be `undefined`
+  - _Note: `default` will also be interpreted as `error`, since its intent is handling unexpected HTTP codes_
 - **response** has response info like `status`, `headers`, etc. It is not typechecked.
 
 ## API

src/index.test.ts

@@ -194,6 +194,18 @@ describe("client", () => {
     });
     expect((await client.get("/self", {})).data).toBe(data);
   });
+
+  it("treats `default` as an error", async () => {
+    const client = createClient<paths>({ headers: { "Cache-Control": "max-age=10000000" } });
+    fetchMocker.mockResponseOnce(() => ({ status: 500, headers: { "Content-Type": "application/json" }, body: JSON.stringify({ code: 500, message: "An unexpected error occurred" }) }));
+    const { error } = await client.get("/default-as-error", {});
+
+    // discard `data` object
+    if (!error) throw new Error("treats `default` as an error: error response should be present");
+
+    // assert `error.message` doesn’t throw TS error
+    expect(error.message).toBe("An unexpected error occurred");
+  });
 });
 
 describe("get()", () => {

src/index.ts

@@ -24,7 +24,8 @@ export interface OperationObject {
 }
 export type HttpMethod = "get" | "put" | "post" | "delete" | "options" | "head" | "patch" | "trace";
 export type OkStatus = 200 | 201 | 202 | 203 | 204 | 206 | 207;
-export type ErrorStatus = 500 | 400 | 401 | 402 | 403 | 404 | 405 | 406 | 407 | 408 | 409 | 410 | 411 | 412 | 413 | 414 | 415 | 416 | 417 | 418 | 420 | 421 | 422 | 423 | 424 | 425 | 426 | 429 | 431 | 444 | 450 | 451 | 497 | 498 | 499;
+// prettier-ignore
+export type ErrorStatus = 500 | 400 | 401 | 402 | 403 | 404 | 405 | 406 | 407 | 408 | 409 | 410 | 411 | 412 | 413 | 414 | 415 | 416 | 417 | 418 | 420 | 421 | 422 | 423 | 424 | 425 | 426 | 429 | 431 | 444 | 450 | 451 | 497 | 498 | 499 | "default";
 
 // util
 /** Get a union of paths which have method */

test/v1.d.ts

@@ -141,6 +141,13 @@ export interface paths {
       };
     };
   };
+  "/default-as-error": {
+    get: {
+      responses: {
+        default: components["responses"]["Error"];
+      };
+    };
+  };
   "/anyMethod": {
     get: {
       responses: {

test/v1.yaml

@@ -124,6 +124,11 @@ paths:
           $ref: '#/components/responses/CreateTag'
         500:
           $ref: '#/components/responses/Error'
+  /default-as-error:
+    get:
+      responses:
+        default:
+          $ref: '#/components/responses/Error'
   /anyMethod:
     get:
       responses: