webpack_bundle_analysis.go

// Make sure you have a `bundle.js` file in the current dir and run this like:
// # go run webpack_bundle_analysis.go | sort -n

package main

import (
	"fmt"
	"io/ioutil"
	"regexp"
	"strings"
)

func check(e error) {
	if e != nil {
		panic(e)
	}
}

func main() {
	re := regexp.MustCompile("[*] [0-9]+ [*]")
	m := make(map[string]int)

	dat, err := ioutil.ReadFile("./bundle.js")
	check(err)

	lines := strings.Split(string(dat), "\n")

	cur := ""

	for _, line := range lines {
		if re.MatchString(line) {
			cur = line
		} else {
			if _, ok := m[cur]; ok {
				m[cur] = m[cur] + len(line)
			} else {
				m[cur] = 0
			}
		}
	}

	total := float64(len(string(dat)))
	for k, v := range m {
		fmt.Printf("%d -- %s -- %f%% of total\n", v, k, float64(v)/total*100)
	}
}