Feat: Added Memoize Func

This commit is contained in:
Damien Chazoule
2021-10-04 13:40:17 +02:00
parent 877ce463c8
commit 028e098b63
2 changed files with 66 additions and 0 deletions

29
Cache/Memoize.js Normal file
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/**
* Memoize
* @param {Function} fn
* @returns
*/
export const memoize = (func) => {
// eslint-disable-next-line no-console
console.log(`Creating cache for function '${func.name}'`)
const cache = {}
return (...args) => {
const [arg] = args
if (arg in cache) {
// eslint-disable-next-line no-console
console.log(`Reading cache with argument ${arg}`)
return cache[arg]
}
// eslint-disable-next-line no-console
console.log(`Updating cache with argument ${arg}`)
const result = func(arg)
cache[arg] = result
return result
}
}

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import { memoize } from '../Memoize'
const fibonacci = (n) => {
if (n < 2) {
return n
}
return fibonacci(n - 2) + fibonacci(n - 1)
}
const factorial = (n) => {
if (n === 0) {
return 1
}
return n * factorial(n - 1)
}
describe('memoize', () => {
it('expects the fibonacci function to use the cache on the second call', () => {
const memoFibonacci = memoize(fibonacci)
expect(memoFibonacci(5)).toEqual(fibonacci(5))
expect(memoFibonacci(5)).toEqual(5)
expect(memoFibonacci(10)).toEqual(fibonacci(10))
expect(memoFibonacci(10)).toEqual(55)
})
it('expects the factorial function to use the cache on the second call', () => {
const memoFactorial = memoize(factorial)
expect(memoFactorial(5)).toEqual(factorial(5))
expect(memoFactorial(5)).toEqual(120)
expect(memoFactorial(10)).toEqual(factorial(10))
expect(memoFactorial(10)).toEqual(3_628_800)
})
})