feat(medusa-react,medusa-js): Allow custom headers (#4409)

* add support for passing custom headers to backend through medusa-js and medusa-react

* switch order of override of headers

* Create gentle-teachers-greet.md

---------

Co-authored-by: Oliver Windall Juhl <59018053+olivermrbl@users.noreply.github.com>

.changeset/gentle-teachers-greet.md

@@ -0,0 +1,6 @@
+---
+"@medusajs/medusa-js": patch
+"medusa-react": patch
+---
+
+feat(medusa-react,medusa-js): Allow custom headers

packages/medusa-js/src/request.ts

@@ -16,6 +16,7 @@ export interface Config {
   maxRetries: number
   apiKey?: string
   publishableApiKey?: string
+  customHeaders?: Record<string, any>
 }
 
 export interface RequestOptions {
@@ -199,6 +200,9 @@ class Client {
     options: RequestOptions = {},
     customHeaders: Record<string, any> = {}
   ): Promise<any> {
+   
+   customHeaders = { ...this.config.customHeaders, ...customHeaders }
+
     const reqOpts = {
       method,
       withCredentials: true,

packages/medusa-react/src/contexts/medusa.tsx

@@ -32,6 +32,7 @@ interface MedusaProviderProps {
    * available within the request
    */
   publishableApiKey?: string
+  customHeaders?: Record<string, any>
 }
 
 export const MedusaProvider = ({
@@ -39,6 +40,7 @@ export const MedusaProvider = ({
   baseUrl,
   apiKey,
   publishableApiKey,
+  customHeaders,
   children,
 }: MedusaProviderProps) => {
   const medusaClient = new Medusa({
@@ -46,6 +48,7 @@ export const MedusaProvider = ({
     maxRetries: 0,
     apiKey,
     publishableApiKey,
+    customHeaders
   })
   return (
     <QueryClientProvider {...queryClientProviderProps}>