fix: Support cargo build --tests by skipping test artifacts

[jssblck]

Summary

Resolves #196.

This PR fixes a crash when running hurry cargo build --tests by explicitly handling and skipping TargetKind::Test artifacts in the build plan.

Context

The crash occurred because hurry encountered an unhandled TargetKind::Test when analyzing the build plan. These artifacts represent the final test binaries (first-party code), which we do not want to cache.

By simply skipping these test artifacts (treating them like TargetKind::Bin), we allow hurry to proceed and correctly process and cache the third-party dependencies that these tests rely on.

Validation

We confirmed that dependencies appear as separate TargetKind::Lib invocations in the build plan, while the test binary itself is TargetKind::Test.

Build Plan Snippet:
(Generated with RUSTC_BOOTSTRAP=1 cargo build --tests --build-plan -Z unstable-options)

{
  "package_name": "serde",
  "target_kind": ["lib"]
},
{
  "package_name": "hurry",
  "target_kind": ["test"]
}

Data Flow

The following diagram demonstrates how hurry processes the build plan, skipping the test binary but capturing its dependencies:

graph TD
    subgraph Cargo["Cargo Build Plan Generation"]
        A["Run: cargo build --tests --build-plan"] --> B{Build Plan Invocations}
        B --> C["Invocation 1: serde (Lib)"]
        B --> D["Invocation 2: tokio (Lib)"]
        B --> E["Invocation 3: my-app (Test Binary)"]
    end

    subgraph Hurry["Hurry Processing Loop (workspace.rs)"]
        F[Start Loop over Invocations] --> G{Check TargetKind}
        
        G -- "TargetKind::Lib / RLib" --> H[Process Dependency]
        H --> I[Create UnitPlan]
        I --> J[Cache/Restore Enabled]
        
        G -- "TargetKind::Bin" --> K["Skip (First-Party)"]
        K --> L[Continue Loop]
        
        G -- "TargetKind::Test" --> M["Skip (First-Party)"]
        M --> N[Continue Loop]
        
        G -- "Other" --> O["Error / Handle"]
    end

    C --> G
    D --> G
    E --> G

    style J fill:#bbf,stroke:#333,stroke-width:2px
    style M fill:#bfb,stroke:#333,stroke-width:2px
    style K fill:#bfb,stroke:#333,stroke-width:2px

Loading

Areas of Interest

• Workspace Logic: packages/hurry/src/cargo/workspace.rs - Added TargetKind::Test to the skip condition in the units() method. This ensures test binaries are treated as first-party code (like TargetKind::Bin) and ignored, preventing the "unsupported target kind" error.

Testing

• Manual Verification: Run hurry cargo build --tests --hurry-skip-restore (or with valid credentials) to verify that the build completes successfully without crashing.

Verification Output

$ cargo run --bin hurry -- cargo build --hurry-skip-restore --tests
...
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.44s
Exit code: 0

Code Map

• Workspace: packages/hurry/src/cargo/workspace.rs:511 - Updated units() to skip TargetKind::Test.

🤖 Generated with Antigravity

[Copilot]

Pull request overview

This PR fixes a crash when running hurry cargo build --tests by adding support for test artifacts in the build plan processing logic. The fix treats test binaries as first-party code (similar to regular binaries) and skips them during caching operations, while still processing their third-party dependencies.

Key changes:

• Extended the skip condition in workspace.rs to handle TargetKind::Test artifacts alongside TargetKind::Bin
• Updated the associated comment to reflect that both binaries and tests are first-party code