minify html in golang to delete extra spaces and next line characters

Question

How to create html minifier?

package main

import (
    "fmt"
)

func HtmlMinify(html string) string {
    // todo: minify html
    return html
}

func main() {

    htmlExample := `<li>
                        <a>Hello</a>
                    </li>`
    minifiedHtml := HtmlMinify(htmlExample)
    fmt.Println(minifiedHtml) //  `<li><a>Hello</a></li>` is wanted
}

outputs:

<li>
                        <a>Hello</a>
                    </li>

But I want it to be

<li><a>Hello</a></li>

playground

Answer 1

Your example could involve simply removing spaces, but minifying html is a bit more complex than that (for instance, you don't want to remove spaces where they actually matters, like within a string).

You can see an example in:

• dchest/htmlmin (doc)
• tdewolff/minify (more complete) (doc)

Answer 2

I used tdewolff/minify:

package main

import (
    "bytes"
    "fmt"
    "github.com/tdewolff/minify"
)

func HtmlMinify(html string) string {
    m := minify.NewMinifierDefault()
    b := &bytes.Buffer{}
    if err := m.HTML(b, bytes.NewBufferString(html)); err != nil {
        panic(err)
    }
    return b.String()
}

func main() {

    htmlExample := `<li>
                        <a>Hello</a>
                    </li>`
    minifiedHtml := HtmlMinify(htmlExample)
    fmt.Println(minifiedHtml) //  <li><a>Hello</a>
}