plugin-preloader/CONTRIBUTING.md

This library dynamically preloads and installs Babel and ESLint plugins and presets based on your configuration, streamlining the build process without the need to include them as dependencies in your project.

# Contributing

## Getting Started

Clone the repo and install dependencies:

```bash
git clone git@github.com:upgradejs/plugin-preloader.git
cd plugin-preloader
npm install
```

To be able to test running the project locally:

```bash
npm run build
npm link
```

## How it works

### Components
This library consists of the following main components:

- **Preload Functions**: `syncPreload` and `asyncPreload` functions are responsible for installing the required Babel and ESLint packages based on their configurations.

- **Configuration Transformers**: `transformBabelConfig` and `transformEslintConfig` functions are used to transform Babel and ESLint configurations into an array of package names and versions.

- **Maps**: The `babelMap` and `eslintMap` objects contain mappings of package names to their corresponding registry names.

- **Utility Functions**: Functions like `getEntitiesMapWithVersionsSync`, `getEntitiesMapWithVersionsAsync`, and various wrappers are provided to help with the internal workings of the library.

### Workflow
Here is a high-level overview of the workflow for preloading Babel and ESLint packages:

1. **Input**: The user provides Babel and/or ESLint configurations to the `syncPreload` or `asyncPreload` functions.

2. **Configuration Transformation**: The configurations are transformed using the `transformBabelConfig` and `transformEslintConfig` functions, resulting in an array of package names and versions.

3. **Mapping**: The transformed package names are mapped to their corresponding registry names using the `babelMap` and `eslintMap` objects.

4. **Version Check**: For each package, the current and desired versions are checked and compared. If the desired version is "latest", the remote latest version is fetched using `npm view`.

5. **Installation**: If any packages need to be installed, they are installed using npm install with the `--no-save` and `--no-audit` flags.

6. **Output**: The library logs the packages to be installed and the output of the npm install command.

## When Submitting a Pull Request:

- If your PR closes any open GitHub issues, please include `Closes #XXXX` in your comment.
- Please include a line in the CHANGELOG.md so that it's easier to release new versions.
- Please include a summary of the change and which issue is fixed or which feature is introduced.
- If changes to the behavior are made, clearly describe what are the changes and why.
- If changes to the UI are made, please include screenshots of the before and after.