Debounce function

.gitignore

@@ -16,7 +16,7 @@ node_modules
 .pnp.*
 
 # testing
-/coverage
+coverage
 .out/
 
 # Build directories (next.js...)

jest.config.base.js

@@ -0,0 +1,11 @@
+module.exports = {
+  preset: 'ts-jest',
+  roots: ['<rootDir>/'],
+  testEnvironment: 'node',
+  collectCoverage: true,
+  coveragePathIgnorePatterns: [
+    '<rootDir>/node_modules/',
+  ],
+  coverageDirectory: '<rootDir>/coverage/',
+  verbose: true
+};

jest.config.js

@@ -0,0 +1,11 @@
+const base = require('./jest.config.base');
+
+module.exports = {
+    ...base,
+    roots: ['<rootDir>'],
+    projects: [
+      '<rootDir>/packages/ui',
+      '<rootDir>/packages/api',
+      '<rootDir>/packages/diceroll'
+    ],
+};

package.json

@@ -9,11 +9,14 @@
   "main": "index.js",
   "private": true,
   "devDependencies": {
+    "@types/jest": "^27.4.1",
     "@types/prettier": "^2.4.4",
     "eslint-plugin-prettier": "^4.0.0",
+    "jest": "^27.5.1",
     "lerna": "^4.0.0",
     "prettier": "^2.5.1",
     "stylus-loader": "^6.2.0",
+    "ts-jest": "^27.1.3",
     "typescript": "^4.6.2"
   },
   "scripts": {

packages/search-engine/__tests__/debunce.test.ts

@@ -0,0 +1,28 @@
+import { debounce } from "../src/scripts/debounce";
+
+jest.useFakeTimers();
+describe('Given the debounce function is used', () => {
+    test('when is called sometimes in a short time period, then should just executed once', () => {
+        const func = jest.fn();
+        const debouncedFunc = debounce(func, 500);
+
+        // Execute for the first time
+        debouncedFunc();
+
+        // Move on the timer
+        jest.advanceTimersByTime(250);
+        // try to execute a 2nd time
+        debouncedFunc();
+
+        // Fast-forward time
+        jest.runAllTimers();
+
+        expect(func).toBeCalledTimes(1);
+    });
+
+    test('when we do not pass a function, then should not execute', () => {
+        const debouncedFunc = debounce(undefined, 500);
+
+        expect(debouncedFunc).toEqual(undefined);
+    });
+});

packages/search-engine/__tests__/search-engine.test.js

@@ -1,7 +1,9 @@
 'use strict';
 
-const searchEngine = require('..');
+// const searchEngine = require('..');
 
 describe('@booking-ui/search-engine', () => {
-    it('needs tests');
+    it('needs tests', () => {
+
+    });
 });

packages/search-engine/jest.config.js

@@ -0,0 +1,9 @@
+const base = require('../../jest.config.base');
+const packageJson = require('./package');
+
+module.exports = {
+    ...base,
+    testEnvironment: 'jsdom', // This is overriden, from the base testEnvironment
+    name: packageJson.name,
+    displayName: packageJson.name,
+};

packages/search-engine/package.json

@@ -21,7 +21,8 @@
     "url": "git+https://github.com/Platzi-Master-C9/booking-ui.git"
   },
   "scripts": {
-    "test": "echo \"Error: run tests from root\" && exit 1"
+    "test": "yarn jest",
+    "test:watch": "yarn jest --watch"
   },
   "bugs": {
     "url": "https://github.com/Platzi-Master-C9/booking-ui/issues"

packages/search-engine/src/scripts/debounce.ts

@@ -0,0 +1,16 @@
+export function debounce (func: () => void, wait: number) {
+  let timeout;
+
+  if(!func)
+    return
+
+  return function () {
+    if(timeout){
+      clearTimeout(timeout);
+    }
+
+    timeout = setTimeout(() => {
+      func.apply(this, arguments);
+    }, wait);
+  };
+}