[ADD] Added and configured 'jest' for unit tests.

Author: Matteo Bilotta

.eslintrc.js

@@ -5,6 +5,7 @@ module.exports = {
   env: {
     browser: true,
     es2021: true,
+    jest: true,
     node: true
   },
   extends: ["eslint:recommended"],

jest.config.js

@@ -0,0 +1,8 @@
+/*
+ * For a detailed explanation regarding each configuration property, visit:
+ * https://jestjs.io/docs/en/configuration.html
+ */
+
+module.exports = {
+  moduleNameMapper: { "^@/(.*)$": "<rootDir>/src/$1" }
+};

jsconfig.json

@@ -0,0 +1,7 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": { "@/*": ["./src/*"] }
+  },
+  "exclude": ["node_modules"]
+}

package.json

@@ -39,14 +39,15 @@
     "ci": "yarn install --frozen-lockfile",
     "lint": "eslint --ignore-path .gitignore .",
     "lint:prod": "export NODE_ENV='production' && yarn lint",
-    "test": "echo \"Sorry! No test specified yet. 😭\" && exit 1"
+    "test": "jest"
   },
   "devDependencies": {
     "@babel/core": "^7.13.16",
     "@babel/eslint-parser": "^7.13.14",
     "@babel/plugin-proposal-class-properties": "^7.13.0",
     "@babel/preset-env": "^7.13.15",
     "eslint": "^7.25.0",
+    "jest": "^26.6.3",
     "vite": "^2.2.3"
   }
 }

tests/html-element-style.test.js

@@ -0,0 +1,11 @@
+import HTMLElementStyle from "@/html-element-style";
+
+const style = new HTMLElementStyle(document.body);
+
+test("Valorize 'margin-top' to '10px'", () =>
+{
+    style["margin-top"] = 10;
+
+    expect(+style.marginTop).toBe(10);
+    expect(`${style.marginTop}`).toBe("10px");
+});

vite.config.js

@@ -7,5 +7,6 @@ module.exports = {
       name: "HTMLElementStyle"
     },
     sourcemap: true
-  }
+  },
+  resolve: { alias: { "@": PATH.resolve(__dirname, "src") } }
 };