fix(js-sdk): Preserve path in baseUrl (#10222)

**What**
- Currently the `js-sdk` will discard the path in the `baseUrl` and only use the `origin`. As an example passing a `baseUrl` of `"http://localhost:9000/custom/path"`, will result in only `"http://localhost:9000"` being used.
- This PR preserves the path, so using `sdk.admin.products()` will make a request to `"http://localhost:9000/custom/path/admin/products`. For an explanation of when this might be useful see this issue: https://github.com/medusajs/medusa/issues/10190#issuecomment-2492974845

Resolves CMRC-740

.changeset/proud-horses-add.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/js-sdk": patch
+---
+
+fix(js-sdk): Preserve path in baseUrl

packages/core/js-sdk/src/__tests__/client.spec.ts

@@ -12,6 +12,11 @@ const server = setupServer(
       test: "test",
     })
   }),
+  http.get(`${baseUrl}/some/path/test`, ({ request, params, cookies }) => {
+    return HttpResponse.json({
+      test: "test",
+    })
+  }),
   http.get(`${baseUrl}/throw`, ({ request, params, cookies }) => {
     return new HttpResponse(null, {
       status: 500,
@@ -184,6 +189,42 @@ describe("Client", () => {
 
       global.window = undefined as any
     })
+
+    it("should handle baseUrl with path correctly", async () => {
+      const pathClient = new Client({
+        baseUrl: `${baseUrl}/some/path`,
+      })
+
+      const resp = await pathClient.fetch<any>("test")
+      expect(resp).toEqual({ test: "test" })
+    })
+
+    it("should handle baseUrl with trailing slash path correctly", async () => {
+      const pathClient = new Client({
+        baseUrl: `${baseUrl}/some/path/`,
+      })
+
+      const resp = await pathClient.fetch<any>("test")
+      expect(resp).toEqual({ test: "test" })
+    })
+
+    it("should handle baseUrl with just origin", async () => {
+      const originClient = new Client({
+        baseUrl,
+      })
+
+      const resp = await originClient.fetch<any>("test")
+      expect(resp).toEqual({ test: "test" })
+    })
+
+    it("should handle baseUrl with just origin and trailing slash", async () => {
+      const originClient = new Client({
+        baseUrl: `${baseUrl}/`,
+      })
+
+      const resp = await originClient.fetch<any>("test")
+      expect(resp).toEqual({ test: "test" })
+    })
   })
 
   describe("GET requests", () => {
@@ -247,4 +288,6 @@ describe("Client", () => {
       global.window = undefined as any
     })
   })
+
+  
 })

packages/core/js-sdk/src/client.ts

@@ -1,5 +1,5 @@
-import qs from "qs"
 import { events } from "fetch-event-stream"
+import qs from "qs"
 import {
   ClientFetch,
   Config,
@@ -224,7 +224,9 @@ export class Client {
 
       let normalizedInput: RequestInfo | URL = input
       if (input instanceof URL || typeof input === "string") {
-        normalizedInput = new URL(input, this.config.baseUrl)
+        const baseUrl = new URL(this.config.baseUrl)
+        const fullPath = `${baseUrl.pathname.replace(/\/$/, '')}/${input.toString().replace(/^\//, '')}`
+        normalizedInput = new URL(fullPath, baseUrl.origin)
         if (init?.query) {
           const params = Object.fromEntries(
             normalizedInput.searchParams.entries()