chore: adding benchmark for worst case

.npmignore

@@ -3,4 +3,5 @@
 demo
 coverage
 .clinic
-doctor-patient.js
+doctor-patient.js
+benchmark.js

README.md

@@ -205,6 +205,25 @@ The cache key is composed based on the following criteria, allowing multiple fil
 - `instanceIdentifier`: A uniqid generated for each instance of the class. It uses the instance properties to generate the id. (JSON.stringify)
 - The arguments passed to the method. (JSON.stringify)
 
+## Benchmarks
+
+An overhead benchmark is available launching the `npm run benchmark` command.  
+The benchmark will run:
+- A simple function without cache-candidate.
+- A cache-candidate wrap of the same function of the first test with an unreachable requestsThreshold.
+- A cache-candidate wrap of the same function of the first test with a candidateFunction that always returns false.
+
+The results on a MacBook Pro M1 2021 with 16GB of RAM are:
+
+```
+cacheCandidate OFF - normalFunction x 47.48 ops/sec ±0.48% (74 runs sampled)
+cacheCandidate ON - Request Threshold unreachable x 46.86 ops/sec ±0.76% (73 runs sampled)
+cacheCandidate ON - Candidate Function set to false x 46.75 ops/sec ±0.47% (72 runs sampled)
+```
+
+The results show that the library has a very low overhead, even when the cache is not used.  
+Our suggestion therefore is to use the library on every function that could benefit from an hypothetical caching.
+
 # Contributing
 
 Please, refer to the [CONTRIBUTING.md](https://github.com/JointlyTech/cache-candidate/blob/main/CONTRIBUTING.md) file for more information.

benchmark.js

@@ -0,0 +1,41 @@
+const {cacheCandidate} = require('./dist');
+const Benchmark = require('benchmark');
+
+let suite = new Benchmark.Suite();
+
+const normalFunction = function() {
+    return new Promise(function(resolve, reject) {
+      setTimeout(function() {
+      resolve(true);
+      }, 20);
+    });
+};
+
+const wrappedNFWithReqThreshold = cacheCandidate(normalFunction, {requestsThreshold: 1_000_000_000});
+const wrappedNFWithCandidateFn = cacheCandidate(normalFunction, {candidateFunction: () => false});
+
+suite.add('cacheCandidate OFF - normalFunction', {
+  defer: true,
+  fn: function (deferred) {
+    normalFunction().then(function() {
+      deferred.resolve();
+    });
+  }
+}).add('cacheCandidate ON - Request Threshold unreachable', {
+  defer: true,
+  fn: function (deferred) {
+      wrappedNFWithReqThreshold().then(function() {
+      deferred.resolve();
+    });
+  }
+}).add('cacheCandidate ON - Candidate Function set to false', {
+  defer: true,
+  fn: function (deferred) {
+      wrappedNFWithCandidateFn().then(function() {
+      deferred.resolve();
+    });
+  }
+}).on('cycle', function(event) {
+    console.log(String(event.target));
+})
+.run({ 'async': true });

package.json

@@ -25,6 +25,7 @@
     "dev": "jest --watch",
     "test": "jest --no-cache",
     "coverage": "jest --coverage",
+    "benchmark": "node benchmark.js",
     "release:common": "npm run build && git push --follow-tags origin main && npm publish --access public",
     "release:patch": "changelog -p && git add CHANGELOG.md && git commit -m 'docs: updated changelog' && npm version patch && npm run release:common",
     "release:minor": "changelog -m && git add CHANGELOG.md && git commit -m 'docs: updated changelog' && npm version minor && npm run release:common",
@@ -40,6 +41,7 @@
     "@types/redis": "^4.0.11",
     "@typescript-eslint/eslint-plugin": "^5.46.0",
     "@typescript-eslint/parser": "^5.46.0",
+    "benchmark": "^2.1.4",
     "esbuild": "^0.16.4",
     "eslint": "^8.29.0",
     "generate-changelog": "^1.8.0",