[FEATURE]: Add Basic Unit Tests for Transaction Signing and Verification

[dhruvi-16-me]

Feature and its Use Cases

📄 Description

MiniChain plans to implement transaction signing and verification using PyNaCl.

Once the core transaction logic is available, it would be beneficial to add a minimal unit test suite to ensure correctness and prevent subtle cryptographic bugs.

Since MiniChain aims to be a clean and educational blockchain implementation, including simple tests would improve reliability without adding unnecessary complexity.

Proposed Test Cases

1. Valid Transaction

   • A properly signed transaction should verify successfully.

2. Modified Transaction Data

   • Changing transaction fields (e.g., amount) after signing should cause verification to fail.

3. Invalid Public Key

   • Using an incorrect public key should fail verification.

4. Replay Protection

   • Reusing a transaction with the same nonce should be rejected by state validation logic.

Suggested Approach

• Use Python’s built-in unittest or pytest
• Add a tests/ directory
• Keep test coverage minimal but focused on correctness

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Why This Matters

• Ensures deterministic and correct signature verification
• Prevents subtle security issues
• Encourages test-driven development
• Keeps the project aligned with its educational goal

Additional Context

No response

Code of Conduct

• I have joined the Discord server and will post updates there
• I have searched existing issues to avoid duplicates