feat(openapi-fetch): baseUrl per request (#1817)

* feat(openapi-fetch): baseUrl per request

* chore: update docs

* chore: add changeset

* fix(openapi-fetch): lint error

* Update .changeset/happy-singers-fry.md

Co-authored-by: Martin Paucot <m.paucot@kmp.agency>

* test: fix typo

---------

Co-authored-by: Martin Paucot <m.paucot@kmp.agency>

Author: Gruak

.changeset/happy-singers-fry.md

@@ -0,0 +1,5 @@
+---
+"openapi-fetch": minor
+---
+
+Allow specifying baseUrl per request

docs/openapi-fetch/api.md

@@ -36,6 +36,7 @@ client.GET("/my-url", options);
 | `querySerializer` | QuerySerializer                                                   | (optional) Provide a [querySerializer](#queryserializer)                                                                                                                                                                          |
 | `bodySerializer`  | BodySerializer                                                    | (optional) Provide a [bodySerializer](#bodyserializer)                                                                                                                                                                            |
 | `parseAs`         | `"json"` \| `"text"` \| `"arrayBuffer"` \| `"blob"` \| `"stream"` | (optional) Parse the response using [a built-in instance method](https://developer.mozilla.org/en-US/docs/Web/API/Response#instance_methods) (default: `"json"`). `"stream"` skips parsing altogether and returns the raw stream. |
+| `baseUrl`         | `string`                                                          | Prefix the fetch URL with this option (e.g. "https://myapi.dev/v1/")                                                                                                                                                              |
 | `fetch`           | `fetch`                                                           | Fetch instance used for requests (default: fetch from `createClient`)                                                                                                                                                             |
 | `middleware`      | `Middleware[]`                                                    | [See docs](/openapi-fetch/middleware-auth)                                                                                                                                                                                        |
 | (Fetch options)   |                                                                   | Any valid fetch option (`headers`, `mode`, `cache`, `signal`, …) ([docs](https://developer.mozilla.org/en-US/docs/Web/API/fetch#options))                                                                                         |

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

@@ -110,6 +110,7 @@ export type FetchResponse<T, Options, Media extends MediaType> =
 
 export type RequestOptions<T> = ParamsOption<T> &
   RequestBodyOption<T> & {
+    baseUrl?: string;
     querySerializer?: QuerySerializer<T> | QuerySerializerOptions;
     bodySerializer?: BodySerializer<T>;
     parseAs?: ParseAs;
@@ -292,3 +293,6 @@ export declare function createFinalURL<O>(
 
 /** Merge headers a and b, with b taking priority */
 export declare function mergeHeaders(...allHeaders: (HeadersOptions | undefined)[]): Headers;
+
+/** Remove trailing slash from url */
+export declare function removeTrailingSlash(url: string): string;

packages/openapi-fetch/src/index.js

@@ -40,9 +40,7 @@ export default function createClient(clientOptions) {
     headers: baseHeaders,
     ...baseOptions
   } = { ...clientOptions };
-  if (baseUrl.endsWith("/")) {
-    baseUrl = baseUrl.substring(0, baseUrl.length - 1);
-  }
+  baseUrl = removeTrailingSlash(baseUrl);
   baseHeaders = mergeHeaders(DEFAULT_HEADERS, baseHeaders);
   const middlewares = [];
 
@@ -53,6 +51,7 @@ export default function createClient(clientOptions) {
    */
   async function coreFetch(schemaPath, fetchOptions) {
     const {
+      baseUrl: localBaseUrl,
       fetch = baseFetch,
       headers,
       params = {},
@@ -61,6 +60,9 @@ export default function createClient(clientOptions) {
       bodySerializer = globalBodySerializer ?? defaultBodySerializer,
       ...init
     } = fetchOptions || {};
+    if (localBaseUrl) {
+      baseUrl = removeTrailingSlash(localBaseUrl);
+    }
 
     let querySerializer =
       typeof globalQuerySerializer === "function"
@@ -563,3 +565,14 @@ export function mergeHeaders(...allHeaders) {
   }
   return finalHeaders;
 }
+
+/**
+ * Remove trailing slash from url
+ * @type {import("./index.js").removeTrailingSlash}
+ */
+export function removeTrailingSlash(url) {
+  if (url.endsWith("/")) {
+    return url.substring(0, url.length - 1);
+  }
+  return url;
+}

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

@@ -777,6 +777,29 @@ describe("client", () => {
       expect(getRequestUrl().href).toBe(toAbsoluteURL("/self"));
     });
 
+    it("baseUrl per request", async () => {
+      const localBaseUrl = "https://api.foo.bar/v1";
+      let client = createClient<paths>({ baseUrl });
+
+      const { getRequestUrl } = useMockRequestHandler({
+        baseUrl: localBaseUrl,
+        method: "get",
+        path: "/self",
+        status: 200,
+        body: { message: "OK" },
+      });
+
+      await client.GET("/self", { baseUrl: localBaseUrl });
+
+      // assert baseUrl and path mesh as expected
+      expect(getRequestUrl().href).toBe(toAbsoluteURL("/self", localBaseUrl));
+
+      client = createClient<paths>({ baseUrl });
+      await client.GET("/self", { baseUrl: localBaseUrl });
+      // assert trailing '/' was removed
+      expect(getRequestUrl().href).toBe(toAbsoluteURL("/self", localBaseUrl));
+    });
+
     describe("headers", () => {
       it("persist", async () => {
         const headers: HeadersInit = { Authorization: "Bearer secrettoken" };
@@ -1282,6 +1305,33 @@ describe("client", () => {
         expect(req.headers.get("onFetch")).toBe("exists");
         expect(req.headers.get("onRequest")).toBe("exists");
       });
+
+      it("baseUrl can be overridden", async () => {
+        useMockRequestHandler({
+          baseUrl: "https://api.foo.bar/v1/",
+          method: "get",
+          path: "/self",
+          status: 200,
+          body: {},
+        });
+
+        let requestBaseUrl = "";
+
+        const client = createClient<paths>({
+          baseUrl,
+        });
+        client.use({
+          onRequest({ options }) {
+            requestBaseUrl = options.baseUrl;
+            return undefined;
+          },
+        });
+
+        await client.GET("/self", {
+          baseUrl: "https://api.foo.bar/v1/",
+        });
+        expect(requestBaseUrl).toBe("https://api.foo.bar/v1");
+      });
     });
   });