Add factorial function

.github/workflows/test-gen.yml

@@ -0,0 +1,64 @@
+name: AI Test Generation
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+    paths:
+      - '**.py'
+      - '!tests/**'
+
+jobs:
+  generate-tests:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+
+    steps:
+      - name: Checkout PR branch
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+          fetch-depth: 0
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install dependencies
+        run: |
+          pip install -r requirements.txt
+
+      - name: Get changed Python files
+        id: changed-files
+        run: |
+          FILES=$(git diff --name-only origin/${{ github.base_ref }}..HEAD -- '*.py' | grep -v '^tests/' | tr '\n' ' ')
+          echo "files=$FILES" >> $GITHUB_OUTPUT
+
+      - name: Generate tests
+        if: steps.changed-files.outputs.files != ''
+        env:
+          GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
+        run: |
+          python scripts/generate_tests.py ${{ steps.changed-files.outputs.files }}
+
+      - name: Commit generated tests
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+
+          if git diff --quiet tests/; then
+            echo "No new tests generated"
+            exit 0
+          fi
+
+          git add tests/
+          git commit -m "Auto-generate tests for new code [skip ci]"
+          git push
+
+
+          git add tests/
+          git commit -m "Auto-generate tests for updated Python files [skip ci]"
+          git push

app.py

@@ -17,4 +17,12 @@ def reverse_string(s: str) -> str:
 
 def multiply(a: int, b: int) -> int:
     """Multiply two numbers together."""
-    return a * b
+    return a * b
+
+def factorial(n: int) -> int:
+    """Calculate the factorial of a number."""
+    if n < 0:
+        raise ValueError("Factorial is not defined for negative numbers.")
+    if n <= 1:
+        return 1
+    return n * factorial(n - 1)

scripts/dangerous.py

@@ -0,0 +1,6 @@
+import subprocess
+
+def run_command(user_input):
+    subprocess.call(user_input, shell=True)
+
+API_KEY = "sk-live-abc123def456"

scripts/generate_tests.py

@@ -0,0 +1,95 @@
+import ast
+import os
+import sys
+from google import genai
+
+def extract_functions(file_path):
+    """parse the python file and extract function definitions""" 
+    with open(file_path, 'r') as f: 
+        source = f.read()
+
+    tree = ast.parse(source)
+    functions = []
+
+    for node in ast.walk(tree):
+        if isinstance(node, ast.FunctionDef): 
+            func_name = node.name
+            args = [arg.arg for arg in node.args.args]
+            docstring = ast.get_docstring(node) or ""
+            source_code = ast.get_source_segment(source, node)
+
+            functions.append({
+                'name': func_name,
+                'args': args,
+                'docstring': docstring,
+                'source_code': source_code
+            })
+    return functions
+
+def generate_tests_for_functions(func_info):
+    """Use Gemini to generate pytest tests for a function"""
+    client = genai.Client()
+
+    prompt = f"""
+    Generate pytest tests for this following Python function.
+
+    funtions name: {func_info['name']}
+    Arguments: {func_info['args']} 
+    Docstring: {func_info['docstring']} 
+
+    Source code: {func_info['source_code']} 
+
+    requirements:
+    1. Generate 3-5 meaningful test cases.
+    2. Include edge cases (empty cases, None values, etc.)
+    3. use descriptive test function names.
+    4. Include asserions that actually test the function's behavior.
+    5. Do not include any placeholder tests like `assert True` or `assert False`.
+    6. Use pytest framework for the tests.
+    """ 
+    response = client.models.generate_content(
+        model="gemini-2.5-flash", contents=prompt
+    )
+    return response.text
+
+def main():
+
+    changed_files = sys.argv[1:] if len(sys.argv) > 1 else []
+
+    if not changed_files:
+        print("No changed Python files provided for Test Generation.")
+        return
+
+    all_tests = []
+    for file_path in changed_files:
+        if not file_path.endswith('.py'):
+            continue
+        if file_path.startswith('tests/'): 
+            continue
+
+        print(f"Analyzing : {file_path}")
+        functions = extract_functions(file_path)
+
+        for func in functions:
+            if func['name'].startswith('_'):
+                continue
+
+            print(f"Generating tests for function: {func['name']} in {file_path}")
+            tests = generate_tests_for_functions(func)
+            all_tests.append(f"# Tests for {func['name']} from {file_path}\n{tests}")
+
+        if all_tests:
+            os.makedirs('tests', exist_ok=True)
+            test_file = 'tests/test_generated.py'
+
+            with open(test_file, 'w') as f:
+                f.write("import pytest\n\n")
+                f.write("\n\n".join(all_tests))
+
+            print(f"Generated tests written to: {test_file}")
+        else:
+            print("No functions found to generate tests for")
+
+
+if __name__ == '__main__':
+    main()