merge: Improved LRUCache (#953)

* feat: added new validation test casses & methods

* style: formated with standard

* feat: added parse method & test cases

* docs: added js docs

* chore: added default import export

Cache/test/LRUCache.test.js

@@ -1,9 +1,19 @@
-import { LRUCache } from '../LRUCache'
+import LRUCache from '../LRUCache'
 import { fibonacciCache } from './cacheTest'
 
-describe('LRUCache', () => {
-  it('Example 1 (Small Cache, size=2)', () => {
-    const cache = new LRUCache(2)
+describe('Testing LRUCache', () => {
+  it('Testing with invalid capacity', () => {
+    expect(() => new LRUCache()).toThrow()
+    expect(() => new LRUCache('Invalid')).toThrow()
+    expect(() => new LRUCache(-1)).toThrow()
+    expect(() => new LRUCache(Infinity)).toThrow()
+  })
+
+  it('Example 1 (Small Cache, size = 2)', () => {
+    const cache = new LRUCache(1) // initially capacity
+
+    cache.capacity++ // now the capacity is increasing by one
+
     cache.set(1, 1)
     cache.set(2, 2)
 
@@ -24,14 +34,41 @@ describe('LRUCache', () => {
     expect(cache.get(3)).toBe(3)
     expect(cache.get(4)).toBe(4)
 
-    expect(cache.cacheInfo()).toBe('CacheInfo(hits=6, misses=3, capacity=2, current size=2)')
+    expect(cache.info).toEqual({
+      misses: 3,
+      hits: 6,
+      capacity: 2,
+      size: 2
+    })
+
+    const json = '{"misses":3,"hits":6,"cache":{"3":3,"4":4}}'
+    expect(cache.toString()).toBe(json)
+
+    // merge with json
+    cache.parse(json)
+
+    cache.capacity-- // now the capacity decreasing by one
+
+    expect(cache.info).toEqual({
+      misses: 6,
+      hits: 12,
+      capacity: 1,
+      size: 1
+    })
   })
 
-  it('Example 2 (Computing Fibonacci Series, size=100)', () => {
+  it('Example 2 (Computing Fibonacci Series, size = 100)', () => {
     const cache = new LRUCache(100)
+
     for (let i = 1; i <= 100; i++) {
       fibonacciCache(i, cache)
     }
-    expect(cache.cacheInfo()).toBe('CacheInfo(hits=193, misses=103, capacity=100, current size=98)')
+
+    expect(cache.info).toEqual({
+      misses: 103,
+      hits: 193,
+      capacity: 100,
+      size: 98
+    })
   })
 })