Add: callback for metadata

Author: Fraggle

package-lock.json

@@ -38,6 +38,7 @@
     "build": "npm run build:esm && npm run build:cjs",
     "build:esm": "tsc -p tsconfig.prod.json && echo '{\"type\": \"module\"}' > dist/esm/package.json",
     "build:cjs": "tsc -p tsconfig.cjs.json && echo '{\"type\": \"commonjs\"}' > dist/cjs/package.json",
+    "prepare": "npm run build",
     "prepack": "npm run build:esm && npm run build:cjs",
     "lint": "eslint src/",
     "test": "jest",

package.json

@@ -26,6 +26,11 @@ export interface OAuthClientProvider {
    */
   state?(): string | Promise<string>;
 
+  /**
+   * If implemented, this permits the OAuth client to save the authorization server metadata.
+   */
+  saveAuthorizationServerMetadata?(metadata?: OAuthMetadata): void | Promise<void>;
+
   /**
    * Loads information about this OAuth client, as registered already with the
    * server, or returns `undefined` if the client is not registered with the
@@ -113,6 +118,10 @@ export async function auth(
 
   const metadata = await discoverOAuthMetadata(authorizationServerUrl);
 
+  if (provider.saveAuthorizationServerMetadata) {
+    await provider.saveAuthorizationServerMetadata(metadata);
+  }
+
   // Handle client registration if needed
   let clientInformation = await Promise.resolve(provider.clientInformation());
   if (!clientInformation) {