feat(clerk-js): Introduce Clerk.client.clearCache() (#1545)

* feat(clerk-js): Introduce Clerk.client.clearCache()

The clearCache method clears the internal token cache for each session of the current client.

Fixes #1525

* feat(clerk-js): Use timer.unref()

Teach ClerkJS Headless not to block the exit of the event loop when used in Node environments.

Author: SokratisVidros

.changeset/swift-rivers-behave.md

@@ -0,0 +1,6 @@
+---
+'@clerk/clerk-js': minor
+'@clerk/types': patch
+---
+
+Introduce Clerk.client.clearCache() method

packages/clerk-js/src/core/resources/Client.ts

@@ -60,6 +60,10 @@ export class Client extends BaseResource implements ClientResource {
     });
   }
 
+  clearCache(): void {
+    return this.sessions.forEach(s => s.clearCache());
+  }
+
   fromJSON(data: ClientJSON | null): this {
     if (data) {
       this.id = data.id;

packages/clerk-js/src/core/resources/Session.ts

@@ -65,6 +65,10 @@ export class Session extends BaseResource implements SessionResource {
     });
   };
 
+  clearCache = (): void => {
+    return SessionTokenCache.clear();
+  };
+
   getToken: GetToken = async (options?: GetTokenOptions): Promise<string | null> => {
     return runWithExponentialBackOff(() => this._getToken(options), {
       shouldRetry: (error: unknown, currentIteration: number) => !is4xxError(error) && currentIteration < 4,

packages/clerk-js/src/core/tokenCache.ts

@@ -50,11 +50,14 @@ export class TokenCacheKey {
 const MemoryTokenCache = (prefix = KEY_PREFIX): TokenCache => {
   const cache = new Map<string, TokenCacheValue>();
 
+  let timer: ReturnType<typeof setTimeout>;
+
   const size = () => {
     return cache.size;
   };
 
   const clear = () => {
+    clearTimeout(timer);
     cache.clear();
   };
 
@@ -83,7 +86,13 @@ const MemoryTokenCache = (prefix = KEY_PREFIX): TokenCache => {
 
         // Mutate cached value and set expirations
         value.expiresIn = expiresIn;
-        setTimeout(deleteKey, expiresIn * 1000);
+        timer = setTimeout(deleteKey, expiresIn * 1000);
+
+        // Teach ClerkJS not to block the exit of the event loop when used in Node environments.
+        // More info at https://nodejs.org/api/timers.html#timeoutunref
+        if (typeof timer.unref === 'function') {
+          timer.unref();
+        }
       })
       .catch(() => {
         deleteKey();

packages/types/src/client.ts

@@ -11,6 +11,7 @@ export interface ClientResource extends ClerkResource {
   isNew: () => boolean;
   create: () => Promise<ClientResource>;
   destroy: () => Promise<void>;
+  clearCache: () => void;
   lastActiveSessionId: string | null;
   createdAt: Date | null;
   updatedAt: Date | null;

packages/types/src/session.ts

@@ -18,6 +18,7 @@ export interface SessionResource extends ClerkResource {
   remove: () => Promise<SessionResource>;
   touch: () => Promise<SessionResource>;
   getToken: GetToken;
+  clearCache: () => void;
   createdAt: Date;
   updatedAt: Date;
 }