Husky And Hooks

Git Hooks & Automation (Husky)

Core Mechanics

Git Hooks are scripts that run automatically every time a particular event occurs in a Git repository (e.g., commit, push). Husky provides a modern approach to managing these hooks via the .husky/ directory.

1. Pre-Commit Hook (lint-staged)

Prevents dirty code from entering the repository.

• Trigger: Runs immediately upon executing git commit.
• Action: Triggers lint-staged which isolates only the files currently in the Git staging area (git add), running formatters (Prettier) and linters (ESLint/Ruff) exclusively on those files.

2. Commit-Msg Hook (commitlint)

Enforces the Conventional Commits specification.

• Trigger: Runs after entering the commit message but before the commit is finalized.
• Action: Triggers @commitlint/cli to parse the message. If it doesn't match type(scope): subject, the commit is aborted.

3. Pre-Push Hook (Test Suite)

• Trigger: Runs upon executing git push.
• Action: Executes the full unit test suite or heavy integration tests to ensure the branch doesn't break the remote pipeline.

Hook Lifecycle Map

%%{init: {"theme": "default", "flowchart": {"useMaxWidth": true}}}%%
flowchart TD
    subgraph Action ["Developer Action"]
        A["git commit -m '...'"]
    end
    
    subgraph Husky ["Husky Interceptor (.husky/)"]
        B["pre-commit hook"]
        C["lint-staged (Format/Lint)"]
        D["commit-msg hook"]
        E["commitlint (Verify Msg)"]
    end
    
    subgraph Result ["Git Core"]
        F["Commit Created (SHA)"]
        G["Commit Aborted (Error)"]
    end
    
    A -->|"Trigger"| B
    B -->|"Execute"| C
    C -->|"Pass"| D
    C -->|"Fail"| G
    D -->|"Execute"| E
    E -->|"Pass"| F
    E -->|"Fail"| G