fix: handle token expiry (#3847)

packages/netlify-cms-backend-github/src/API.ts

@@ -202,11 +202,15 @@ export default class API {
 
   user(): Promise<{ name: string; login: string }> {
     if (!this._userPromise) {
-      this._userPromise = this.request('/user') as Promise<GitHubUser>;
+      this._userPromise = this.getUser();
     }
     return this._userPromise;
   }
 
+  getUser() {
+    return this.request('/user') as Promise<GitHubUser>;
+  }
+
   async hasWriteAccess() {
     try {
       const result: Octokit.ReposGetResponse = await this.request(this.repoURL);

packages/netlify-cms-backend-github/src/implementation.tsx

@@ -111,6 +111,19 @@ export default class GitHub implements Implementation {
     return true;
   }
 
+  async status() {
+    const auth =
+      (await this.api
+        ?.getUser()
+        .then(user => !!user)
+        .catch(e => {
+          console.warn('Failed getting GitHub user', e);
+          return false;
+        })) || false;
+
+    return { auth };
+  }
+
   authComponent() {
     const wrappedAuthenticationPage = (props: Record<string, unknown>) => (
       <AuthenticationPage {...props} backend={this} />