Prevent infinite loop when calling foreach after deleting head (#194)

Author: szogun1987

packages/cache/src/lru.test.ts

@@ -193,7 +193,18 @@ describe('lru()', () => {
  cache.write('baz', 'boz')
 
  const results: string[] = []
- cache.forEach((value) => results.push(value))
+ cache.forEach((key) => results.push(key))
  expect(results).toEqual(['baz', 'bar', 'foo'])
  })
+
+ it('should not iterate over deleted head', () => {
+ const cache = lru<string, string>(Infinity)
+ cache.write('foo', 'bar')
+ cache.write('bar', 'baz')
+ cache.delete('bar')
+
+ const results: string[] = []
+ cache.forEach((key) => results.push(key))
+ expect(results).toEqual(['foo'])
+ })
 })

packages/cache/src/lru.ts

@@ -107,6 +107,9 @@ export const lru = <Key = string, Value = any>(
  if (this.size === 1) {
  this.head = undefined
  } else {
+ if (node === this.head) {
+ this.head = node.prev
+ }
  node.prev.next = node.next
  node.next.prev = node.prev
  }