Selki/ff3396 expiring bandit cache

src/cache/tlru-cache.spec.ts

@@ -50,35 +50,41 @@ describe('TLRU Cache', () => {
   it('should evict all expired entries on .keys() call', () => {
     jest.useFakeTimers();
 
+    cache = new TLRUCache(3, expectedCacheTimeoutMs);
     cache.set('a', 'avocado');
     jest.advanceTimersByTime(expectedCacheTimeoutMs);
     cache.set('b', 'banana');
     jest.advanceTimersByTime(expectedCacheTimeoutMs);
+    cache.set('c', 'cherry');
 
     const cacheKeys = [];
 
     for (const key of cache.keys()) {
       cacheKeys.push(key);
     }
 
-    expect(cacheKeys.length).toBe(0);
+    expect(cacheKeys.length).toBe(1);
+    expect(cache.get('c')).toBe('cherry');
   });
 
   it('should evict all expired entries on .values() call', () => {
     jest.useFakeTimers();
+    cache = new TLRUCache(3, expectedCacheTimeoutMs);
 
     cache.set('a', 'avocado');
     jest.advanceTimersByTime(expectedCacheTimeoutMs);
     cache.set('b', 'banana');
     jest.advanceTimersByTime(expectedCacheTimeoutMs);
+    cache.set('c', 'cherry');
 
     const cacheValues = [];
 
     for (const value of cache.values()) {
       cacheValues.push(value);
     }
 
-    expect(cacheValues.length).toBe(0);
+    expect(cacheValues.length).toBe(1);
+    expect(cache.get('c')).toBe('cherry');
   });
 
   it('should overwrite existing cache entry', () => {
@@ -152,8 +158,18 @@ describe('TLRU Cache', () => {
     cache.set('b', 'banana');
     cache.set('c', 'cherry');
 
-    const keys = Array.from(cache.keys());
+    let keys = Array.from(cache.keys());
     expect(keys[0]).toBe('b');
     expect(keys[1]).toBe('c');
+
+    cache = new TLRUCache(2, expectedCacheTimeoutMs);
+    cache.set('a', 'apple');
+    cache.set('b', 'banana');
+    cache.get('a');
+    cache.set('c', 'cherry');
+
+    keys = Array.from(cache.keys());
+    expect(keys[0]).toBe('a');
+    expect(keys[1]).toBe('c');
   });
 });

src/cache/tlru-cache.ts

@@ -73,30 +73,22 @@ export class TLRUCache extends LRUCache {
     return super.delete(key);
   }
 
-  // has(key: string): boolean {
-  //   const hasValue = this.cache.has(key);
-  //
-  //   if (!this.isCacheEntryValid(key)) {
-  //     this.delete(key);
-  //     return false;
-  //   }
-  //
-  //   return hasValue;
-  // }
+  has(key: string): boolean {
+    if (!this.isCacheEntryValid(key)) {
+      this.delete(key);
+      return false;
+    }
+    return this.cache.has(key);
+  }
 
   get(key: string): string | undefined {
-    if (!this.cache.has(key)) {
+    if (!this.isCacheEntryValid(key)) {
+      this.delete(key);
       return undefined;
     }
 
-    const value = this.cache.get(key);
-
+    const value = super.get(key);
     if (value !== undefined) {
-      if (!this.isCacheEntryValid(key)) {
-        this.delete(key);
-        return undefined;
-      }
-
       // Whenever we get a cache hit, we need to reset the timer
       // for eviction, because it is now considered most recently
       // accessed thus the timer should start over. Not doing that