fix(mobile): normalize Expo fetch URLs

Generated-By: PostHog Code
Task-Id: 11daf8d3-7830-436a-ab8f-99123586070d

Author: richardsolomou

apps/mobile/src/lib/posthogApiClient.test.ts

@@ -97,13 +97,29 @@ describe("createPostHogApiClient", () => {
       teamId: 123,
       options: {
         appVersion: "1.2.3",
-        fetch: mocks.expoFetch,
         githubConnectFrom: "posthog_mobile",
         userAgent: "posthog/mobile.hog.dev; version: 1.2.3",
       },
     });
   });
 
+  it("converts URL inputs before calling Expo fetch", async () => {
+    const { createPostHogApiClient } = await import("./posthogApiClient");
+    createPostHogApiClient();
+    const mobileFetch = mocks.instances[0]?.options.fetch as typeof fetch;
+    const init = { method: "GET" };
+
+    await mobileFetch(
+      new URL("https://us.posthog.com/api/projects/2/tasks/"),
+      init,
+    );
+
+    expect(mocks.expoFetch).toHaveBeenCalledWith(
+      "https://us.posthog.com/api/projects/2/tasks/",
+      init,
+    );
+  });
+
   it("falls back to the Expo config version", async () => {
     mocks.expoApplication.nativeApplicationVersion = null;
     mocks.expoConstants.expoConfig = { version: "4.5.6" };

apps/mobile/src/lib/posthogApiClient.ts

@@ -11,6 +11,16 @@ const MOBILE_GITHUB_CONNECT_FROM = "posthog_mobile";
 let posthogApiClient: PostHogAPIClient | null = null;
 let posthogApiHost: string | null = null;
 
+const mobileFetch: FetchImplementation = (input, init) =>
+  fetch(
+    typeof input === "string"
+      ? input
+      : input instanceof URL
+        ? input.toString()
+        : input.url,
+    init,
+  );
+
 function getAppVersion(): string {
   return (
     Application.nativeApplicationVersion ??
@@ -63,7 +73,7 @@ export function createPostHogApiClient(): PostHogAPIClient {
     projectId,
     {
       appVersion,
-      fetch: fetch as FetchImplementation,
+      fetch: mobileFetch,
       githubConnectFrom: MOBILE_GITHUB_CONNECT_FROM,
       userAgent: `posthog/mobile.hog.dev; version: ${appVersion}`,
     },