Confirmed Software Developer Internship - Coding Exercise

What I built

Part A - C#/.NET console application

• Accepts a GitHub username as a command-line argument.
• Uses the GitHub public API (GET /users/{username}/repos) to fetch that user's public repositories.
• Maps the API response into an internal C# model (RepositorySummary).
• Fetches all pages (pagination, per_page=100) so the top 5 by stargazer count are correct for users with many repos.
• Prints readable console output: repository name, description, stars, primary language, repository URL, last updated date.
• Writes the normalized results to a local JSON file (repos.json by default) for the React app to consume.
• Uses HttpClient, deserializes JSON into C# models, and handles invalid input, empty results, 404, and failed HTTP responses (with retry for transient/5xx).

Part B - React interface

• Small React (Vite + TypeScript) app that displays the normalized repo data.
• Loads data from the JSON file produced by the console app (or from public/repos.json / sample file for local development).
• Displays records in a clean, readable UI (cards with name, description, stars, language, URL, last updated).
• Interactive features: search (filter by name or description) and sort (by stars, name A-Z, or last updated).

Optional enhancements included

• Unit tests - C#: xUnit in console-app.Tests/. React: Vitest + Testing Library in react-app/src.
• Dependency injection - C#: ServiceCollection, AddHttpClient, config and logging from the container.
• Configuration - C#: appsettings.json plus environment variables (e.g. Output__FilePath, GitHub__ApiBaseUrl). React: VITE_REPOS_JSON_URL.
• Logging - C#: ILogger with console logging.
• Retry - C#: Polly (3 attempts, exponential backoff) for transient/5xx. React: fetchWithRetry for failed/5xx responses.
• Pagination - C#: GitHub API pagination so top 5 by stars is correct across all repos.

---

How to run both parts

Prerequisites: .NET 10 SDK, Node.js (for the React app).

Part A - Console app

cd console-app
dotnet run -- <github-username>

Example: dotnet run -- inseokk

• Output is printed to the console and written to repos.json in the current directory (or the path in appsettings.json / env Output__FilePath).
• To run the console app tests: dotnet test console-app.Tests/console-app.Tests.csproj (from repo root or from console-app).

Part B - React app

1. For local development without running the console app, ensure react-app/public/repos.json exists (you can copy from console-app/repos.json after running Part A once).
2. From the repo root:

cd react-app
npm install
npm run dev

• Open the URL shown (e.g. http://localhost:5173). The app loads /repos.json by default; override with VITE_REPOS_JSON_URL if needed.
• To run the React tests: npm run test.

---

Assumptions

• The console app is run from the console-app directory (or with a working directory where appsettings.json is present) so config and output paths resolve correctly.
• The React app is served by Vite dev server or similar, and repos.json is either in public/ or provided via the same origin (or VITE_REPOS_JSON_URL).
• JSON schema: same as the C# RepositorySummary (Name, Description, Stars, PrimaryLanguage, Url, LastUpdated). The React app expects this schema.
• GitHub API is used unauthenticated; rate limits apply for heavy use.

What I would improve with more time

• React: Add filter by primary language and/or expand/collapse per card; improve loading/error UX (e.g. skeleton, retry button).
• C#: Add more unit tests (e.g. pagination behavior, retry behavior); optional integration test against a test GitHub user or mocked server.
• DevOps: Add a simple script or instructions to run the console app and copy repos.json into react-app/public/ for a one-command full demo flow.
• Accessibility: Audit and improve keyboard navigation and screen reader support in the React app.