Add factorial function

.github/workflows/ci.yml

@@ -0,0 +1,36 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install dependencies
+        run: pip install -r requirements.txt
+
+      - name: Run tests
+        run: pytest -q
+
+      - name: Build package
+        run: python -m build
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: python-package
+          path: dist/
+

.github/workflows/pr-review.yml

@@ -0,0 +1,56 @@
+name: AI Code Review
+
+on:
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  review:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install dependencies
+        run: pip install -r requirements.txt
+
+      - name: Get PR diff
+        run: |
+          git diff origin/main...HEAD > pr_diff.txt
+
+      - name: Run AI review
+        id: ai-review
+        env:
+          GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
+        run: |
+          REVIEW=$(python scripts/ai_review.py pr_diff.txt)
+          echo "review<<EOF" >> $GITHUB_OUTPUT
+          echo "$REVIEW" >> $GITHUB_OUTPUT
+          echo "EOF" >> $GITHUB_OUTPUT
+
+      - name: Post review comment
+        uses: actions/github-script@v7
+        env:
+          REVIEW: ${{ steps.ai-review.outputs.review }}
+        with:
+          script: |
+            const review = process.env.REVIEW;
+
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body: `## 🤖 AI Code Review\n\n${review}\n\n---\n*Powered by Gemini AI*`
+            });

app.py

@@ -14,3 +14,7 @@ def is_even(n: int) -> bool:
 def reverse_string(s: str) -> str:
     """Reverse a string."""
     return s[::-1]
+
+def multiply(a: int, b: int):
+    """Mutltiply two numbers"""
+    return a * b

requirements.txt

@@ -1,4 +1,5 @@
 # Production dependencies (none for this simple app)
+google-genai>=1.0.0
 
 # Development/testing dependencies
 pytest>=7.0.0

scripts/ai_review.py

@@ -0,0 +1,38 @@
+import sys
+import os
+from google import genai
+
+# Configure your Gemini API key
+client = genai.Client(api_key=os.environ.get("GEMINI_API_KEY"))
+
+def review_code(diff_text: str) -> str:
+    """Send a code diff to Gemini and return its review."""
+    prompt = f"""You are a code reviewer. Review the following code diff and check for:
+- Bugs or errors
+- Security vulnerabilities (e.g. SQL injection)
+- Style and readability issues
+
+If the code looks good, say so.
+
+Code diff to review:
+
+{diff_text}
+
+Provide your review in a clear, structured format."""
+
+    response = client.models.generate_content(model="gemini-2.5-flash", contents=prompt)
+    return response.text
+
+
+if __name__ == "__main__":
+    # Check if a filename was passed as a command-line argument
+    if len(sys.argv) > 1:
+        diff_file = sys.argv[1]
+        with open(diff_file, "r") as f:
+            diff_content = f.read()
+    else:
+        # If no file was provided, read from stdin (e.g. piped input)
+        diff_content = sys.stdin.read()
+
+    review = review_code(diff_content)
+    print(review)

scripts/generate_tests.py

@@ -0,0 +1,90 @@
+import ast
+from google import genai
+import sys
+import os
+
+
+def extract_functions(file_path):
+    #Read the source code
+    with open(file_path, "r") as f:
+        source = f.read()
+
+    #parse it into a tree
+    tree = ast.parse(source)
+
+    #Walk through the tree to find node
+    function = []
+    for node in ast.walk(tree):
+        if isinstance(node, ast.FunctionDef):
+            func_info = {
+                "name": node.name,
+                "arguments": [ag.arg for arg in node args.args],
+                "docstring": ast.get_docstring(node),
+                "source": ast.get_source_segment(source, node),
+            }
+            functions.append(func_info)
+        return function
+
+
+def generate_tests_for_function(func_info):
+    client = genai.Client(api_key=os.environ.get('GEMINI_API_KEY'))
+    prompt = f"""
+    You are an expert Python developer. Generate 3 - 5 meaningful pytest test cases for the following function.
+
+    Function name: {func_info['name']}
+    Arguments: {func_info['arguments']}
+    Docstring: {func_info['docstring']}
+    Source: {func_info['source']}
+
+    Rules:
+    - Do not write placeholder tests like assert True or assert False
+    - Each tests must actually call the function with real arguments.
+    - Test edge cases like empty input, negative numbers, or none where relevant
+    - Each testfunction must have a descriptive name explaining what it tests
+    - Only return the code, no explanations
+    """
+
+   response = client.models.generate_content(
+    model="gemini-2.0-flash",
+    contents=prompt
+   )  
+
+   return response.txt
+
+
+
+def main():
+    file_paths = sys.argv[1:]
+
+    all_tests = []
+
+    for file_path in file_paths:
+        if not file_path.endswith(".py"):
+            print(f"Skipping {file_path} — not a Python file")
+            continue
+
+        if "test" in file_path:
+            print(f"Skipping {file_path} — looks like a test file")
+            continue
+
+        functions = extract_functions(file_path)
+
+        for func in functions:
+            if func["name"].startswith("_"):
+                print(f"Skipping private function: {func['name']}")
+                continue
+
+            print(f"Generating tests for {func['name']}...")
+            tests = generate_tests_for_function(func)
+            all_tests.append(tests)
+
+    os.mkdir("tests", exist_ok=True)
+
+    with open("tests/test_generated.py", "w") as f:
+        f.write("\n\n".join(all_tests))
+
+    print("Done! Tests written to tests/test_generated.py")
+
+
+if __name__ == '__main__':
+    main()

scripts/scripts/sample_diff.txt

@@ -0,0 +1,16 @@
+diff --git a/app.py b/app.py
+index 1234567..abcdefg 100644
+--- a/app.py
++++ b/app.py
+@@ -1,5 +1,12 @@
+ """Simple utility functions"""
++import sqlite3
++
++def get_user(username):
++    conn = sqlite3.connect("users.db")
++    query = f"SELECT * FROM users WHERE name = '{username}'"
++    return conn.execute(query).fetchone()
++
+ def add(a: int, b: int) -> int:
+     """Add two numbers together."""
+     return a + b

tests/test_app.py

@@ -1,6 +1,6 @@
 """Tests for app.py - you'll add more!"""
 
-from app import add, is_even, reverse_string
+from app import add, is_even, reverse_string, multiply
 
 
 class TestMath:
@@ -22,3 +22,17 @@ def test_reverse(self):
     def test_is_even(self):
         assert is_even(4) is True
         assert is_even(3) is False
+
+
+    class TestMultiply:
+        """Test for multiply function"""
+
+        def test_multiply_positive_numbers(self):
+            assert multiply(4, 4) == 16
+
+        def test_multiply_by_zero(self):
+            assert multiply(4, 0) == 0
+
+        def test_multiply_negatives_numbers(self):
+            assert multiply(-5, -10) == 50
+