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86d333ee94
* chore: Switch to Node 20 + Vitest * chore: migrate to vitest mock functions * chore: code style (switch to prettier) * test: re-enable long-running test Seems the switch to Node 20 and Vitest has vastly improved the code's and / or the test's runtime! see #1193 * chore: code style * chore: fix failing tests * Updated Documentation in README.md * Update contribution guidelines to state usage of Prettier * fix: set prettier printWidth back to 80 * chore: apply updated code style automatically * fix: set prettier line endings to lf again * chore: apply updated code style automatically --------- Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com> Co-authored-by: Lars Müller <34514239+appgurueu@users.noreply.github.com>
61 lines
2.0 KiB
JavaScript
61 lines
2.0 KiB
JavaScript
/**
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* @function memoize
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* @description ->
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* From [Wikipedia](https://en.wikipedia.org/wiki/Memoization),
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* memoization is an optimization technique
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* used primarily to speed up computer programs,
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* by storing the results of expensive function calls
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* and returning the cached result when the same inputs occur again
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* This function is a first class objects,
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* which lets us use it as [Higher-Order Function](https://eloquentjavascript.net/05_higher_order.html)
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* and return another function
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* @param {Function} func Original function
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* @param {Map} cache - it's receive any cache DS which have get, set & has method
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* @returns {Function} Memoized function
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*/
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const memoize = (func, cache = new Map()) => {
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const jsonReplacer = (_, value) => {
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if (value instanceof Set) {
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// if the value is Set it's converted to Array cause JSON.stringify can't convert Set
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return [...value]
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}
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if (value instanceof Map) {
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// if the value is Map it's converted to Object cause JSON.stringify can't convert Map
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return Object.fromEntries(value)
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}
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return value
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}
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return (...args) => {
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/**
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* Arguments converted to JSON string for use as a key of Map - it's easy to detect collections like -> Object and Array
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* If the args input is -> [new Set([1, 2, 3, 4]), {name: 'myName', age: 23}]
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* Then the argsKey generate to -> '[[1,2,3,4],{"name":"myName","age":23}]' which is JSON mean string
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* Now it's ready to be a perfect key for Map
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*/
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const argsKey = JSON.stringify(args, jsonReplacer)
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/**
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* Checks if the argument is already present in the cache,
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* then return the associated value / result
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*/
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if (cache.has(argsKey)) {
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return cache.get(argsKey)
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}
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/**
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* If the argument is not yet present in the cache,
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* execute original function and save its value / result in cache,
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* finally return it
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*/
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const result = func(...args) // spread all args
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cache.set(argsKey, result)
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return result
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}
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}
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export { memoize }
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