CSC/ECE 517 Spring 2024 - G2402 Implement REST client, REST API, and Graphql API endpoint for repositories - Part 2

Project Objective

This project aims to create a robust tool enabling users to access and analyze their GitHub metrics conveniently. The phase one objective was to develop API endpoints leveraging GitHub GraphQL and GitHub REST queries within a Python Flask framework. This involves integrating Flask with existing code to expose GraphQL queries as API endpoints, building a REST client, and establishing REST endpoints for streamlined data retrieval.
Subsequently, in phase two of the project, each API endpoint established in the initial phase will be complemented with a React-based frontend. This frontend will be specifically designed to visualize and present the GitHub data retrieved through these endpoints in an intuitive user interface. The goal is to seamlessly integrate backend functionality with frontend design to enhance user interaction and data presentation.

Below is the MVC architecture of our GitHub project:

Plan of Work

In the second phase of the project, we will focus on developing a robust and user-friendly frontend using React. The frontend will serve as an intuitive interface for displaying and interacting with the data retrieved from the GitHub API endpoints implemented in the first phase.

The plan includes the following key steps:

1. Setup React Environment:

• Selecting Tooling and Libraries: Choose an appropriate React setup such as Create React App for rapid development or Next.js for server-side rendering and enhanced performance.
• Dependency Management: Use npm or Yarn to manage project dependencies, including React, ReactDOM, and additional libraries for state management (Redux, Recoil), routing (React Router), and styling (styled-components, Tailwind CSS).
• Project Structure: Organize the project structure with components, containers, services, and utility folders to maintain a scalable and maintainable codebase.

2. Design UI Components:

• Translate the data from the API endpoints into interactive React components, focusing on usability and accessibility standards.
• Component Composition: Create reusable and composable UI components following component-based design principles, leveraging hooks (useState, useEffect) for managing state and side effects.
• Styling: Implement consistent styling using CSS-in-JS solutions like styled-components or CSS modules, ensuring modular and scoped styles for each component.

3. Integrate with API Endpoints:

• HTTP Requests: Use Axios or Fetch API to handle asynchronous data fetching from the backend API endpoints implemented in phase one.
• State Management: Implement state management (e.g., Redux, Context API) to store and manage fetched data centrally across components, ensuring efficient data flow and reactivity.
• Optimizing Performance: Implement memoization techniques (e.g., useMemo, useCallback) to optimize re-renders and reduce unnecessary API calls.

4. Implement Pagination:

• Pagination Logic: Develop pagination logic to manage and display large datasets in manageable chunks, adhering to RESTful API standards for page-based navigation.
• UI Components: Create pagination controls (e.g., buttons, page indicators) to allow users to navigate through paginated data smoothly, updating the UI dynamically based on user interactions.

5. Enhance User Experience:

• We will focus on improving the user experience by adding features such as search functionality, filtering, sorting, and other relevant enhancements based on the data being displayed. These enhancements will empower users to interact with the data more effectively and derive valuable insights.
• Interactive Visualizations: Integrate interactive charts (e.g., using Chart.js, D3.js) to visually represent data trends and insights, enhancing user engagement and understanding.

6. Test and Debug:

• Unit Testing: Write unit tests using Jest and React Testing Library to ensure individual components render correctly and exhibit expected behavior based on props and state.
• Integration Testing: Conduct integration tests to validate API integrations, data flow, and interactions between frontend components.
• Cross-Browser Compatibility: Perform cross-browser testing (e.g., Chrome, Firefox, Safari) and responsive testing to ensure consistent rendering and functionality across different browsers and devices.

7. Deploy and Document: Finally, we will deploy the React frontend to a hosting platform, ensuring it is accessible and easily usable by end-users. Comprehensive documentation will be provided, including instructions for setup, usage, and any relevant information for future maintenance and development.

Frontend

As shown below, we plan to display contributors' individual contribution and commit count. We will be implementing the UI using ReactJS

Commits page with number of commits

GraphQL Endpoints

Get current user login:

/api/graphql/current-user-login

Sample Output:

{
  "viewer": {
    "login": "<your-username>"
  }
}

Get specific user login:

/api/graphql/user-login/<username>

Get list of all commits in a repo:

/api/graphql/specific-user-commits/<owner>/<repo_name>

Sample Output: {

   "repository": {
     "defaultBranchRef": {
       "target": {
         "history": {
           "nodes": [
             {
               "additions": 0,
               "author": {
                 "email": "61797592+Atharva7007@users.noreply.github.com",
                 "name": "Atharva Pansare",
                 "user": {
                   "login": "Atharva7007"
                 }
               },
               "authoredDate": "2020-04-03T09:30:17Z",
               "changedFilesIfAvailable": 1,
               "deletions": 0,
               "message": "Add files via upload",
               "parents": {
                 "totalCount": 1
               }
             }
           ],
           "pageInfo": {
             "endCursor": "98ba34a6c62ff6fe7c4d4de5c342a194f72d66e4 0",
             "hasNextPage": true
           },
           "totalCount": 6
         }
       }
     }
   }
 },

Get details of all contributors in a repo:

/api/graphql/repository-contributors/<owner>/<repo_name>

Sample Output: {

   "repository": {
     "defaultBranchRef": {
       "target": {
         "history": {
           "nodes": [
             {
               "author": {
                 "email": "61797592+Atharva7007@users.noreply.github.com",
                 "name": "Atharva Pansare",
                 "user": {
                   "login": "Atharva7007"
                 }
               }
             }
           ],
           "pageInfo": {
             "endCursor": "98ba34a6c62ff6fe7c4d4de5c342a194f72d66e4 0",
             "hasNextPage": true
           },
           "totalCount": 6
         }
       }
     }
   }
 }

REST API Endpoints

Get current user login:

/api/rest/current-user-login-rest

This endpoint retrieves the login information of the currently authenticated user. It fetches the user's profile data from the GitHub API and returns details such as their username, avatar URL, and other relevant information.

Sample Output:

{
  "avatar_url": "https://avatars.githubusercontent.com/u/61797592?v=4",
  "bio": null,
  "blog": "",
  "company": null,
  "created_at": "2020-03-04T16:49:06Z",
  "email": null,
  "events_url": "https://api.github.com/users/Atharva7007/events{/privacy}",
  "followers": 1,
  "followers_url": "https://api.github.com/users/Atharva7007/followers",
  "following": 3,
  "following_url": "https://api.github.com/users/Atharva7007/following{/other_user}",
  "gists_url": "https://api.github.com/users/Atharva7007/gists{/gist_id}",
  "gravatar_id": "",
  "hireable": null,
  "html_url": "https://github.com/Atharva7007",
  "id": 61797592,
  "location": null,
  "login": "Atharva7007",
  "name": "Atharva Pansare",
  "node_id": "MDQ6VXNlcjYxNzk3NTky",
  "organizations_url": "https://api.github.com/users/Atharva7007/orgs",
  "public_gists": 0,
  "public_repos": 11,
  "received_events_url": "https://api.github.com/users/Atharva7007/received_events",
  "repos_url": "https://api.github.com/users/Atharva7007/repos",
  "site_admin": false,
  "starred_url": "https://api.github.com/users/Atharva7007/starred{/owner}{/repo}",
  "subscriptions_url": "https://api.github.com/users/Atharva7007/subscriptions",
  "twitter_username": null,
  "type": "User",
  "updated_at": "2024-03-14T19:03:46Z",
  "url": "https://api.github.com/users/Atharva7007"
}

Get list of all commits in a repo:

/api/rest/specific-user-commits/<owner>/<repo_name>

This endpoint retrieves a list of all commits made to a specific repository. It takes the repository owner and repository name as parameters. The endpoint fetches the commit history from the GitHub API and returns details about each commit, such as the author, commit message, and changes made.

Sample Output:

[
  {
    "repository": {
      "defaultBranchRef": {
        "target": {
          "history": {
            "nodes": [
              {
                "additions": 0,
                "author": {
                  "email": "61797592+Atharva7007@users.noreply.github.com",
                  "name": "Atharva Pansare",
                  "user": {
                    "login": "Atharva7007"
                  }
                },
                "authoredDate": "2020-04-03T09:30:17Z",
                "changedFilesIfAvailable": 1,
                "deletions": 0,
                "message": "Add files via upload",
                "parents": {
                  "totalCount": 1
                }
              }
            ],
            "pageInfo": {
              "endCursor": "98ba34a6c62ff6fe7c4d4de5c342a194f72d66e4 0",
              "hasNextPage": true
            },
            "totalCount": 6
          }
        }
      }
    }
  }
]

Get details of all contributors in a repo:

/api/rest/repository-contributors/<owner>/<repo_name>

This endpoint fetches the details of all contributors to a specific repository. It takes the repository owner and repository name as parameters. The endpoint retrieves the list of contributors from the GitHub API and returns information about each contributor, such as their username, avatar URL, and permissions within the repository.

Sample Output: [

 {
   "avatar_url": "https://avatars.githubusercontent.com/u/61797592?v=4",
   "events_url": "https://api.github.com/users/Atharva7007/events{/privacy}",
   "followers_url": "https://api.github.com/users/Atharva7007/followers",
   "following_url": "https://api.github.com/users/Atharva7007/following{/other_user}",
   "gists_url": "https://api.github.com/users/Atharva7007/gists{/gist_id}",
   "gravatar_id": "",
   "html_url": "https://github.com/Atharva7007",
   "id": 61797592,
   "login": "Atharva7007",
   "node_id": "MDQ6VXNlcjYxNzk3NTky",
   "organizations_url": "https://api.github.com/users/Atharva7007/orgs",
   "permissions": {
     "admin": true,
     "maintain": true,
     "pull": true,
     "push": true,
     "triage": true
   },
   "received_events_url": "https://api.github.com/users/Atharva7007/received_events",
   "repos_url": "https://api.github.com/users/Atharva7007/repos",
   "role_name": "admin",
   "site_admin": false,
   "starred_url": "https://api.github.com/users/Atharva7007/starred{/owner}{/repo}",
   "subscriptions_url": "https://api.github.com/users/Atharva7007/subscriptions",
   "type": "User",
   "url": "https://api.github.com/users/Atharva7007"
 }

]

Implementation Details

The GitHub Miner project consists of two main components: the backend API and the frontend user interface.

The backend API is implemented using Flask, a lightweight Python web framework. It exposes two sets of endpoints: one for GraphQL queries and another for REST API queries. Flask Blueprints are used to route requests to the appropriate endpoints based on the URL path.

The GraphQL implementation utilizes the `graphene` library, which provides a way to define GraphQL schemas and resolvers. The resolvers are responsible for fetching data from the GitHub API using the `pygithub` library.

The REST implementation uses the `requests` library to make HTTP requests to the GitHub API and process the responses.

To ensure reliability and robustness, comprehensive testing strategies, including unit tests and integration tests, have been implemented. These tests validate the functionality of the API endpoints across different scenarios, ensuring the system's correctness and stability.

In the API, we have 2 separate endpoints to retrieve the same data: one for REST and the other using GraphQL queries. To manage this, we have made use of Flask Blueprints where all the "api/graphql" requests get routed to the graphql variants and the "api/rest" requests get routed to the REST variants.

Design Patterns used

1. The REST API Client /backend/app/services/github_query/github_rest/client.py is a Singleton.

Testing

To ensure the reliability and robustness of the GitHub Miner, comprehensive testing strategies, including unit tests and integration tests, have been implemented. These tests validate the functionality of the API endpoints across different scenarios, ensuring the system's correctness and stability. The testing suite covers the following areas:

Unit Tests

Unit tests have been developed to test individual components in isolation, ensuring that each part functions correctly on its own. This section details the unit tests for both the GitHub GraphQL integration and specific queries related to GitHub data retrieval:

1. 1. 1. 1. GitHub GraphQL Tests

- **test_authentication.py**: Ensures robust authentication by testing token handling and refresh mechanisms. - **test_client.py**: Validates the GraphQL client's initialization, error handling, and proper response parsing. - **test_query.py**: Checks the correct formation, execution, and error handling of GraphQL queries.

1. 1. 1. 1. Queries Tests

- **Comments**: Confirms accurate retrieval and parsing of comments from GitHub repositories. - **Contributions**: Verifies the accuracy and completeness of contribution data, including commits and pull requests. - **Costs**: Tests accurate cost calculation for managing API rate limits. - **Profiles**: Ensures comprehensive fetching and correct parsing of user profiles. - **Repositories**: Validates retrieval of detailed repository information. - **Time Range Contributions**: Assesses the accuracy of fetching and aggregating contributions within specified time ranges.

Integration Tests

Integration tests verify the interaction between different components of the system, ensuring that they work together as expected. These tests are crucial for assessing the seamless operation of front-end to back-end interactions and the overall data flow within the application:

- **TestClient**: Tests the GitHub client's ability to initialize correctly, generate headers, handle retries, execute queries efficiently, and manage paginated responses. - **Authentication Tests**: Validates the generation of correct authorization headers and proper handling of personal access tokens.

Testing Examples

Here, we provide specific examples of test cases implemented in our project. You can see how we approach testing for both unit and integration levels, focusing on key functionalities and integration points.

{ import pytest import requests_mock from unittest.mock import MagicMock from datetime import datetime, timezone from requests.exceptions import Timeout from backend.app.services.github_query.github_graphql.client import Client, InvalidAuthenticationError, QueryFailedException from backend.app.services.github_query.github_graphql.authentication import PersonalAccessTokenAuthenticator from backend.app.services.github_query.github_graphql.query import Query, PaginatedQuery from backend.app.services.github_query.github_rest.client import RESTClient

@pytest.fixture def valid_token():

   return "valid_token_123"

@pytest.fixture def authenticator(valid_token):

   return PersonalAccessTokenAuthenticator(token=valid_token)

@pytest.fixture def github_client(authenticator):

   return Client(authenticator=authenticator)

class TestClient:

   def test_client_without_authenticator(self):
       """Test that client raises error when no authenticator is provided"""
       with pytest.raises(InvalidAuthenticationError):
           Client()  # No authenticator provided

   def test_client_initialization(self, github_client):
       """Test that the client is correctly initialized with the given authenticator"""
       assert github_client._authenticator is not None, "Authenticator should be set."

   def test_client_base_path(self, github_client):
       """Test that the base path is correctly constructed"""
       assert "api.github.com" in github_client._base_path(), "Base path should include the host."
   
   def test_generate_headers(self, github_client, authenticator):
       """Test that headers are correctly generated including authorization and additional headers."""
       additional_headers = {"Custom-Header": "CustomValue"}
       expected_headers = authenticator.get_authorization_header()
       expected_headers.update(additional_headers)

       assert github_client._generate_headers(**additional_headers) == expected_headers, "Headers should include both authenticator and additional headers."

   def test_retry_success(self, github_client, requests_mock):
       """Test that retry_request succeeds after a retry."""
       # Mock the request to timeout once then succeed
       requests_mock.register_uri('POST', github_client._base_path(), [
           {'exc': Timeout},
           {'json': {'data': 'success'}, 'status_code': 200}
       ])
       
       response = github_client._retry_request(2, 1, "query { viewer { login }}", {})
       assert response.json() == {'data': 'success'}, "Should succeed on the second attempt."

   def test_retry_timeout(self, github_client, requests_mock):
       """Test that retry_request gives up after attempts are exhausted."""
       # Mock the request to timeout
       requests_mock.register_uri('POST', github_client._base_path(), [
           {'exc': Timeout},
           {'exc': Timeout}
       ])
       
       with pytest.raises(Timeout):
           github_client._retry_request(2, 1, "query { viewer { login }}", {})

   def test_execute_success(self, github_client, requests_mock):
       """Test successful execution of a query."""
       # Mock the rate limit pre-check and the actual query execution
       requests_mock.post(github_client._base_path(), [
           {'json': {"data": {"rateLimit": {"cost": 1, "remaining": 5000, "resetAt": "2021-01-01T00:00:00Z"}}}, 'status_code': 200},
           {'json': {"data": "query success"}, 'status_code': 200}
       ])
       response = github_client._execute("query { viewer { login }}", {})
       assert response == "query success", "Execute should return success on valid response."

   def test_execute_rate_limit_exceeded(self, github_client, requests_mock):
       """Test execution of a query leading to waiting for rate limit reset."""
       # Set specific values for cost, remaining, and resetAt
       mock_cost = 10
       mock_remaining = 14  # Ensure remaining - 5 < mock_cost
       # mock_reset_at = datetime.utcnow().strftime('%Y-%m-%dT%H:%M:%SZ')
       mock_reset_at = datetime.now(timezone.utc).strftime('%Y-%m-%dT%H:%M:%SZ')

       # Mock rate limit response
       mock_rate_limit_response = {
           "data": {
               "rateLimit": {
                   "cost": mock_cost,
                   "remaining": mock_remaining,
                   "resetAt": mock_reset_at
               }
           }
       }

       # Setup requests_mock to simulate the rate limit response and any subsequent requests
       base_path = github_client._base_path()
       requests_mock.post(base_path, [
           {'json': mock_rate_limit_response, 'status_code': 200},
           {'json': {"data": "query success"}, 'status_code': 200}
       ])
       response = github_client._execute("query { viewer { login }}", {})
       assert response == "query success", "Execute should return success on valid response."

   def test_execute_query_failed(self, github_client, requests_mock):
       """Test execution of a query leading to QueryFailedException with retries."""
       # Mock a failed query response for each retry attempt
       requests_mock.post(github_client._base_path(), [
           {'json': {"data": {"rateLimit": {"cost": 1, "remaining": 5000, "resetAt": "2021-01-01T00:00:00Z"}}}, 'status_code': 200},
           {"json": {"error": "bad request"}, "status_code": 400}
       ])
       # Expecting QueryFailedException after all retries have been exhausted
       with pytest.raises(QueryFailedException):
           github_client._execute("query { viewer { login }}", {})
   
   def test_execution_generator(self, github_client):
       """Test that _execution_generator correctly handles paginated responses."""
       # Setup a mock paginated query
       query = MagicMock()
       query.paginator.has_next.side_effect = [True, True, False]  # Simulate 2 pages of results, then stop
       query.path = []  # Example path, adjust based on your actual usage

       # Mock the _execute method to return simulated page results
       github_client._execute = MagicMock()
       github_client._execute.side_effect = [
           {"pageInfo": {"endCursor": "cursor1", "hasNextPage": True}, "nodes": [{"edges": "data1"}]},
           {"pageInfo": {"endCursor": "cursor2", "hasNextPage": False}, "nodes": [{"edges": "data2"}]}
       ]

       # Mock the update_paginator method to reflect the changing state of pagination
       query.paginator.update_paginator = MagicMock()

       # Collect all results from the generator
       results = list(github_client._execution_generator(query, {}))

       # Assertions
       assert len(results) == 2, "Should yield two results for the two pages"
       assert results[0]['nodes'][0]['edges'] == "data1", "First result should match first mocked response"
       assert results[1]['nodes'][0]['edges'] == "data2", "Second result should match second mocked response"

       # Ensure update_paginator was called correctly
       assert query.paginator.update_paginator.call_count == 2, "update_paginator should be called twice, once per page"
       query.paginator.update_paginator.assert_called_with(False, "cursor2")  # Last call should reflect the end of pagination

   def test_client_execute_success(self, github_client, requests_mock):
       """Test successful execution of a query"""
       requests_mock.post(github_client._base_path(), [
           {'json': {"data": {"rateLimit": {"cost": 1, "remaining": 5000, "resetAt": "2021-01-01T00:00:00Z"}}}, 'status_code': 200},
           {'json': {"data": "query success"}, 'status_code': 200}
       ])
       response = github_client.execute(Query("query { viewer { login }}"), {})
       assert response == "query success", "Execute should return success on valid response."

   def test_client_execute_failed(self, github_client, requests_mock):
       """Test that a failed query raises QueryFailedException"""
       requests_mock.post(github_client._base_path(), [
           {'json': {"data": {"rateLimit": {"cost": 1, "remaining": 5000, "resetAt": "2021-01-01T00:00:00Z"}}}, 'status_code': 200},
           {"json": {"error": "bad request"}, "status_code": 400}
       ])
       with pytest.raises(QueryFailedException) as excinfo:
           github_client.execute(Query("query { viewer { login }}"), {})
       assert "Query failed with code" in str(excinfo.value), "QueryFailedException should contain the right error message."

}

These tests collectively ensure that the GitHub Miner operates reliably, providing accurate and timely data from GitHub's APIs. By covering a wide range of scenarios, from successful queries to error handling and rate limiting, the tests ensure that the application can be used confidently in production environments.

Live Demo & Source Code

http://152.7.177.239:5000/auth/login Link] (Please login using your personal GitHub accounts, not NCSU accounts)

Source Code

Team Members

Atharva Pansare

Sumedh Limburkar

Viraj Sanap

Mengning Li

Mentor: Jialin Cui

References

GitHub REST API documentation - https://docs.github.com/en/rest?apiVersion=2022-11-28