Custom Plugin

GV supports a plugin system to customize how files are resolved, loaded, transformed, and handled during development. To write your own plugin, implement the Plugin interface provided by GV.

Plugin Interface

type Plugin interface {
	Name() string
	OnStart() error
	ResolveId(ctx *Context, id string, importer string) (*ResolveResult, error)
	Load(ctx *Context, id string) (*LoadResult, error)
	Transform(ctx *Context, code string, id string) (*TransformResult, error)
	HandleHotUpdate(filePath string) error
}

You can embed the PluginBase struct to inherit default no-op implementations:

type MyPlugin struct {
	PluginBase
}

Example Plugin

Here’s a basic example of a plugin that logs every file it transforms:

type LoggerPlugin struct {
	PluginBase
}

func (p *LoggerPlugin) Name() string {
	return "logger"
}

func (p *LoggerPlugin) Transform(ctx *Context, code string, id string) (*TransformResult, error) {
	fmt.Println("Transforming:", id)
	return &TransformResult{Code: code}, nil
}

Registering the Plugin

To use your plugin, add it to the list of plugins when initializing GV:

plugins := []Plugin{
	&LoggerPlugin{},
	// other plugins...
}

Notes

• Name(): should return a unique plugin name.
• OnStart(): is called once when the plugin system initializes.
• ResolveId(): is used to handle import paths (e.g., aliases, bare modules).
• Load(): lets you provide custom file content after resolution.
• Transform(): is where you can transpile or modify file contents.
• HandleHotUpdate(): is triggered on file change during dev (HMR).