webassets

A fast, flexible Go package for serving static web assets with in-memory caching, on-the-fly minification, and virtual bundle support.

Features

• In-memory caching: Serve assets from memory for maximum performance.
• On-the-fly minification: Minify JavaScript and CSS using tdewolff/minify.
• Virtual bundles: Concatenate and serve multiple files as a single asset (e.g., app.bundle.js).
• Singleflight protection: Prevents duplicate work under concurrent load.
• Customizable error logging: Plug in your own logger for visibility into handled errors.
• Cache exclusion: Exclude specific URL prefixes from caching.
• Secure by default: Files prefixed with _ are not served.

Installation

go get github.com/cornejong/webassets

Usage

import (
    "net/http"
    "github.com/cornejong/webassets"
)

func main() {
    h := webassets.New("./web/static",
        webassets.WithCache(true),
        webassets.WithMinification(true),
        webassets.WithBundle("app.bundle.js", "js/vendor.js", "js/app.js"),
        webassets.WithErrorLogger(func(err error) { log.Println("webassets error:", err) }),
    )
    http.Handle("/assets/", http.StripPrefix("/assets", h))
    http.ListenAndServe(":8080", nil)
}

Options

• WithCache(enabled bool): Enable or disable in-memory caching.
• WithCacheExclude(prefixes ...string): Exclude URL prefixes from caching.
• WithMinification(enabled bool): Enable or disable JS/CSS minification.
• WithBundle(name string, files ...string): Register a virtual bundle.
• WithErrorLogger(fn func(error)): Set a custom error logger.

Bundles

Bundles are virtual files that concatenate multiple source files. Example:

webassets.WithBundle("app.bundle.js", "js/vendor.js", "js/app.js")

Requesting /assets/app.bundle.js will serve the concatenated and minified result.

Security

• Files prefixed with _ (e.g., _secret.js) are not served.
• Only text-based files are minified and (future) compressed.

Roadmap

• Transparent gzip/brotli compression with content negotiation
• ETag/Last-Modified support for bundles
• Live reload/dev mode helpers

License

MIT