ci(rust): integrate Rust unit testing and linting into CI pipeline

This MR sets up unit testing/linting for the Rust components of the gitalisk project. It sets up the necessary infrastructure to run tests, linting, and formatting checks for our Rust code, both locally for developers and within our GitLab CI pipeline.

Related Issues

• follows gitlab-code-parser!5 (merged)
• closes [gitalisk] Setup Unit Tests (#1 - closed)

What's Changed

• CI/CD Pipeline for Rust: New jobs have been added to .gitlab-ci.yml to automatically test, lint, and check formatting for all Rust code on each merge request. This includes:
  • rust-unit-tests: A job to run cargo test.
  • lint:rust-fmt-check: Ensures code adheres to rustfmt standards.
  • lint:rust-lint-check: Uses clippy to enforce code quality. The CI configuration uses a cache for Cargo dependencies to speed up subsequent pipeline runs.
• Developer Workflow Enhancements:
  • lefthook.yml is now configured with pre-push hooks to run tests, formatting, and lint checks before code is pushed. This helps catch issues locally before they reach the main branch.
  • A rust-toolchain.toml file has been added to pin the Rust version to stable and ensure all developers use the same toolchain with rustfmt and clippy.
• Code Refinements: Some of the existing Rust code has been refactored for better practices, including improved error handling and removal of some unused code. The tempfile dependency was added to support test creation.

Technical Details

Test and CI Setup

The new testing infrastructure is based on standard Rust tooling. Here's a look at the key configurations:

CI Pipeline Job:

.rust-job-template:
  image: ${GITLAB_DEPENDENCY_PROXY}rust:latest
  cache:
    key:
      files: [Cargo.toml, Cargo.lock]
    paths: [.cargo/*, target/debug/*]

Pre-push Hook:

pre-push:
  parallel: true
  commands:
    rust_test:
      run: cargo test -- --nocapture