added tests for isIsogram function

.eslintrc.js

@@ -1,10 +1,10 @@
 module.exports = {
-  extends: '@mate-academy/eslint-config',
+  extends: "@mate-academy/eslint-config",
   env: {
-    jest: true
+    jest: true,
   },
   rules: {
-    'no-proto': 0
+    "no-proto": 0,
   },
-  plugins: ['jest']
+  plugins: ["jest"],
 };

.github/workflows/test.yml

@@ -11,7 +11,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [12.x]
+        node-version: [20.x]
 
     steps:
     - uses: actions/checkout@v2

.github/workflows/test.yml-template

@@ -0,0 +1,23 @@
+name: Test
+
+on:
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [20.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm install
+    - run: npm test