✨ Add pop/shift methods for SlidingTaskMap

Author: Tomas2D

src/SlidingTaskMap.ts

@@ -17,7 +17,7 @@ class SlidingTaskMap<K, V extends Deletable> extends TaskMap<K, V> {
     }
 
     if (this.size + 1 > this.windowSize) {
-      this.delete(this.keysByTime[0]);
+      this.shift();
     }
     this.keysByTime.push(key);
     return super.set(key, value);
@@ -32,10 +32,28 @@ class SlidingTaskMap<K, V extends Deletable> extends TaskMap<K, V> {
     return didDelete;
   }
 
-  clear() {
+  clear(): void {
     super.clear();
     this.keysByTime.length = 0;
   }
+
+  pop(): boolean {
+    if (this.keysByTime.length === 0) {
+      return false;
+    }
+
+    const key = this.keysByTime[this.keysByTime.length - 1];
+    return this.delete(key);
+  }
+
+  shift(): boolean {
+    if (this.keysByTime.length === 0) {
+      return false;
+    }
+
+    const key = this.keysByTime[0];
+    return this.delete(key);
+  }
 }
 
 export default SlidingTaskMap;

test/SlidingTaskMap.test.ts

@@ -50,4 +50,35 @@ describe('SlidingTaskMap', () => {
     // @ts-expect-error simulating no type safety env
     expect(() => new SlidingTaskMap('x')).toThrow();
   });
+
+  it('Removes element from front (shift)', async () => {
+    const map = new SlidingTaskMap<string, Task<number>>(5);
+    expect(map.pop()).toBe(false);
+    expect(map.shift()).toBe(false);
+
+    const tasks = [new Task<number>(), new Task<number>(), new Task<number>()];
+
+    map.set('1', tasks[0]);
+    map.set('2', tasks[1]);
+    map.set('3', tasks[2]);
+
+    expect(map.size).toBe(3);
+
+    expect(map.pop()).toBe(true);
+    expect(map.size).toBe(2);
+    expect(map.has('1')).toBe(true);
+    expect(map.has('2')).toBe(true);
+    expect(map.has('3')).toBe(false);
+
+    expect(map.shift()).toBe(true);
+    expect(map.size).toBe(1);
+    expect(map.has('1')).toBe(false);
+    expect(map.has('2')).toBe(true);
+    expect(map.has('3')).toBe(false);
+
+    expect(map.pop()).toBe(true);
+    expect(map.size).toBe(0);
+    expect(map.has('1')).toBe(false);
+    expect(map.shift()).toBe(false);
+  });
 });