Building Your First AI-Powered Test Case Generator

1# Simple architecture
2User Input (Feature Description)
3  ↓
4Prompt Template (Your QA expertise)
5  ↓
6OpenAI API (GPT-4)
7  ↓
8Test Cases (Your format)
9  ↓
10Output (CSV, JSON, or direct to test tool)

1# Create virtual environment
2python -m venv venv
3source venv/bin/activate  # On Windows: venv\Scripts\activate
4
5# Install dependencies
6pip install openai python-dotenv
7
8# Create .env file
9echo "OPENAI_API_KEY=your_key_here" > .env

1from string import Template
2
3# Your QA expertise goes here
4PROMPT_TEMPLATE = Template("""
5You are a senior QA engineer. Generate comprehensive test cases for the following feature.
6
7Feature Name: $feature_name
8Description: $description
9User Story: $user_story
10
11Requirements:
12$requirements
13
14Generate test cases in this exact format:
15
16Test Case ID | Title | Preconditions | Steps | Expected Result | Priority | Type
17
18Include:
19- Positive test cases (happy path)
20- Negative test cases (error handling)
21- Edge cases and boundary conditions
22- Security considerations
23- Performance edge cases
24
25Use Given-When-Then format for steps.
26Priority: Critical, High, Medium, Low
27Type: Functional, Security, Performance, Usability
28
29Generate 15-20 test cases covering all scenarios.
30""")

1import os
2from openai import OpenAI
3from dotenv import load_dotenv
4from prompt_template import PROMPT_TEMPLATE
5
6load_dotenv()
7
8class TestCaseGenerator:
9  def __init__(self):
10      self.client = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))
11
12  def generate(self, feature_name, description, user_story, requirements):
13      """Generate test cases for a feature"""
14
15      # Fill in the prompt template
16      prompt = PROMPT_TEMPLATE.substitute(
17          feature_name=feature_name,
18          description=description,
19          user_story=user_story,
20          requirements=requirements
21      )
22
23      # Call OpenAI API
24      response = self.client.chat.completions.create(
25          model="gpt-4",  # or "gpt-4-turbo" for faster/cheaper
26          messages=[
27              {
28                  "role": "system",
29                  "content": "You are an expert QA engineer specializing in test case design."
30              },
31              {
32                  "role": "user",
33                  "content": prompt
34              }
35          ],
36          temperature=0.7,  # Balance creativity and consistency
37          max_tokens=2000
38      )
39
40      return response.choices[0].message.content
41
42  def save_to_csv(self, test_cases, filename):
43      """Save generated test cases to CSV"""
44      with open(filename, 'w') as f:
45          f.write(test_cases)
46      print(f"Test cases saved to {filename}")
47
48# Usage
49if __name__ == "__main__":
50  generator = TestCaseGenerator()
51
52  test_cases = generator.generate(
53      feature_name="User Login",
54      description="Email/password authentication with remember me option",
55      user_story="As a user, I want to log in with my email and password so I can access my account",
56      requirements="""
57      - Email and password fields required
58      - "Remember me" checkbox (optional)
59      - Forgot password link
60      - Account lockout after 5 failed attempts
61      - Session timeout after 30 minutes of inactivity
62      """
63  )
64
65  generator.save_to_csv(test_cases, "login_test_cases.csv")
66  print(test_cases)

1# Add this to your generator class
2class TestCaseGenerator:
3  def __init__(self, domain_context=None):
4      self.client = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))
5      self.domain_context = domain_context or self.default_domain_context()
6
7  def default_domain_context(self):
8      """Your domain expertise"""
9      return """
10      Domain: E-commerce web application
11
12      Standard Security Checks:
13      - SQL injection attempts
14      - XSS attacks
15      - CSRF protection
16      - Session hijacking
17
18      Common Edge Cases:
19      - Unicode characters in inputs
20      - Very long strings (>1000 chars)
21      - Special characters in email
22      - Concurrent user sessions
23
24      Compliance Requirements:
25      - GDPR data handling
26      - PCI DSS for payment data
27      - WCAG 2.1 AA accessibility
28
29      Performance Baselines:
30      - Page load: <2 seconds
31      - API response: <500ms
32      - Support 1000 concurrent users
33      """
34
35  def generate(self, feature_name, description, user_story, requirements):
36      # Prepend domain context to every prompt
37      full_prompt = f"{self.domain_context}\n\n{PROMPT_TEMPLATE.substitute(...)}"
38      # ... rest of the method

1import json
2from test_case_generator import TestCaseGenerator
3
4def batch_generate(features_file):
5  """Generate test cases for multiple features from JSON"""
6
7  generator = TestCaseGenerator()
8
9  # Load features from JSON
10  with open(features_file, 'r') as f:
11      features = json.load(f)
12
13  results = {}
14
15  for feature in features:
16      print(f"Generating test cases for: {feature['name']}...")
17
18      test_cases = generator.generate(
19          feature_name=feature['name'],
20          description=feature['description'],
21          user_story=feature['user_story'],
22          requirements=feature['requirements']
23      )
24
25      results[feature['name']] = test_cases
26
27      # Save individual files
28      filename = f"test_cases_{feature['name'].lower().replace(' ', '_')}.csv"
29      generator.save_to_csv(test_cases, filename)
30
31  return results
32
33# Usage: python batch_processor.py features.json
34if __name__ == "__main__":
35  import sys
36  batch_generate(sys.argv[1])

1[
2{
3  "name": "User Login",
4  "description": "Email/password authentication",
5  "user_story": "As a user, I want to log in...",
6  "requirements": "- Email required\n- Password required..."
7},
8{
9  "name": "Product Search",
10  "description": "Search products by keyword",
11  "user_story": "As a user, I want to search...",
12  "requirements": "- Search bar\n- Filters..."
13}
14]

1from jira import JIRA
2
3class JiraIntegration:
4  def __init__(self, server, email, api_token):
5      self.jira = JIRA(server=server, basic_auth=(email, api_token))
6
7  def create_test_case(self, project_key, test_case):
8      """Create a test case in Jira"""
9      issue_dict = {
10          'project': {'key': project_key},
11          'summary': test_case['title'],
12          'description': self.format_test_case(test_case),
13          'issuetype': {'name': 'Test'},
14      }
15
16      new_issue = self.jira.create_issue(fields=issue_dict)
17      return new_issue.key
18
19  def format_test_case(self, test_case):
20      """Format test case for Jira"""
21      return f"""
22      *Preconditions:*
23      {test_case['preconditions']}
24
25      *Steps:*
26      {test_case['steps']}
27
28      *Expected Result:*
29      {test_case['expected_result']}
30
31      *Priority:* {test_case['priority']}
32      *Type:* {test_case['type']}
33      """
34
35# Usage
36jira = JiraIntegration(
37  server="https://your-domain.atlassian.net",
38  email="your-email@example.com",
39  api_token="your_api_token"
40)
41
42jira.create_test_case("PROJ", test_case)

1Bad: "Generate test cases"
2Good: "Generate test cases in this EXACT format: [format]
3Do not add any extra text before or after the table."

1# Add example test cases to your prompt
2EXAMPLE_TEST_CASE = """
3Example of a good test case:
4TC-001 | Login with valid credentials | User has account | GIVEN user on login page WHEN enters valid email and password THEN redirected to dashboard | Success | Critical | Functional
5"""

1"Also consider these edge cases:
2- Very long inputs (>1000 characters)
3- Special characters: <>"'&
4- Concurrent requests
5- Network timeouts
6- Database failures"