fix: ts client If refreshing wait for the existing refreshing promise (…

…#1680)

node/templates/client/core.ts

@@ -147,6 +147,11 @@ export class Core {
      */
     refreshToken: this.config?.refreshTokenStore || new InMemoryStore(),
 
+    /**
+     * A promise that resolves when the session is refreshed.
+     */
+    refreshingPromise: undefined as Promise<APIResult<AuthenticationResponse>> | undefined,
+
     /**
      * Returns data field set to the list of supported authentication providers and their SSO login URLs.
      * Returns error field if an unexpected error occurred.
@@ -317,10 +322,17 @@ export class Core {
         };
       }
 
-      const authResponse = await this.auth.requestToken({
-        grant_type: "refresh_token",
-        refresh_token: refreshToken,
-      });
+      // If refreshing already, wait for the existing refreshing promisee
+      if (!this.auth.refreshingPromise) {
+          this.auth.refreshingPromise = this.auth.requestToken({
+            grant_type: "refresh_token",
+            refresh_token: refreshToken,
+          });
+      }
+
+      const authResponse = await this.auth.refreshingPromise;
+
+      this.auth.refreshingPromise = undefined;
 
       if (authResponse.error) {
         return { error: authResponse.error };