diff --git a/.github/workflows/lab-autograding.yml b/.github/workflows/lab-autograding.yml
index ba7a31f9..033b2a2e 100644
--- a/.github/workflows/lab-autograding.yml
+++ b/.github/workflows/lab-autograding.yml
@@ -12,13 +12,17 @@ jobs:
                 os: [ubuntu-22.04]
             fail-fast: false
         steps:
-            - uses: actions/checkout@v4
+            - name: Checkout repository
+              uses: actions/checkout@v4
               with:
                   ref: "${{ github.event.pull_request.merge_commit_sha }}"
                   fetch-depth: 1
-            - uses: actions/setup-node@v4
+
+            - name: Set up Node.js
+              uses: actions/setup-node@v4
               with:
-                  node-version: latest
+                  node-version: '20'
+
             - name: Extract lab number and Check no changes other than specific files
               uses: actions/github-script@v5
               id: lab
@@ -40,16 +44,17 @@ jobs:
                         return { number: 0 };
                       }
                       const labNumber = labNumberMatch[1];
-                      console.log(`Lab number: ${labNumber}`)
+                      console.log(`Lab number: ${labNumber}`);
 
                       const files = await github.rest.pulls.listFiles({ owner, repo, pull_number: issue_number });
                       const changedFiles = files.data.map((file) => file.filename);
                       const allowedFileRegex = /^lab\d+\/main_test.js$/;
                       const specialChangedFiles = ["lab5/Answer.md", "lab5/antiasan.c", "lab6/Answer.md", "lab7/sol.py"];
-                      if (!changedFiles.every((file) => (allowedFileRegex.test(file) || specialChangedFiles.includes(file)))) {
+                      if (!changedFiles.every((file) => allowedFileRegex.test(file) || specialChangedFiles.includes(file))) {
                         core.setFailed('The PR contains changes to files other than the allowed files.');
                       }
                       return labNumber;
+
             - name: Grading
               run: |
                   cd lab${{ steps.lab.outputs.result }}
diff --git a/lab3/main_test.js b/lab3/main_test.js
index 096fd421..9b2cb75d 100644
--- a/lab3/main_test.js
+++ b/lab3/main_test.js
@@ -2,4 +2,62 @@ const { describe, it } = require('node:test');
 const assert = require('assert');
 const { Calculator } = require('./main');
 
+
+describe('Calculator', () => {
+    const calculator = new Calculator();
+
+    describe('exp function', () => {
+        it('calculates the exponential of a number', async () => {
+            assert.strictEqual(calculator.exp(1), Math.exp(1));
+        });
+
+        it('throws error on non-finite input', async () => {
+            assert.throws(() => calculator.exp('a'), {
+                name: 'Error',
+                message: 'unsupported operand type'
+            });
+            assert.throws(() => calculator.exp(Infinity), {
+                name: 'Error',
+                message: 'unsupported operand type'
+            });
+        });
+
+        it('handles overflow', async () => {
+            assert.throws(() => calculator.exp(1000), {
+                name: 'Error',
+                message: 'overflow'
+            });
+        });
+    });
+
+    describe('log function', () => {
+        it('calculates the logarithm of a number', async () => {
+            assert.strictEqual(calculator.log(Math.E), Math.log(Math.E));
+        });
+
+        it('throws error on non-finite input', async () => {
+            assert.throws(() => calculator.log('a'), {
+                name: 'Error',
+                message: 'unsupported operand type'
+            });
+            assert.throws(() => calculator.log(-1), {
+                name: 'Error',
+                message: 'math domain error (1)'
+            });
+        });
+
+        it('handles domain errors', async () => {
+            assert.throws(() => calculator.log(0), {
+                name: 'Error',
+                message: 'math domain error (1)'
+            });
+            assert.throws(() => calculator.log(null), {
+                name: 'Error',
+                message: 'unsupported operand type'
+            });
+        });
+    });
+});
+
+
 // TODO: write your tests here