yassinebenaid/godump

Dump any GO variable with ease

godump

A versatile Go library designed to output any Go variable in a structured and colored format.

This library is especially useful for debugging and testing when the standard fmt library falls short in displaying arbitrary data effectively. It can also serve as a powerful logging adapter, providing clear and readable logs for both development and production environments.

godump is not here to replace the fmt package. Instead, it provides an extension to what the fmt.Printf("%#v") can do.

Why godump

• ability to pretty print values of all types
• well formatted output
• unexported structs are dumped too
• pointers are followed, and recursive pointers are taken in mind (see examples)
• customizable, you have full control over the output, you can even generate HTML if you'd like to, see examples
• zero dependencies

Get Started

Install the library:

go get -u github.com/yassinebenaid/godump

Then use the Dump function:

package main

import (
	"github.com/yassinebenaid/godump"
)

func main() {
	godump.Dump("Anything")
}

Customization

If you need more control over the output. Use the Dumper

package main

import (
	"os"

	"github.com/yassinebenaid/godump"
)

func main() {

	var v = "Foo Bar"
	var d = godump.Dumper{
		Indentation:       "  ",
		HidePrivateFields: false,
		Theme: godump.Theme{
			String: godump.RGB{R: 138, G: 201, B: 38},
			// ...
		},
	}

	d.Print(v)
	d.Println(v)
	d.Fprint(os.Stdout, v)
	d.Fprintln(os.Stdout, v)
	d.Sprint(v)
	d.Sprintln(v)
}

Demo

Example 1.

package main

import (
	"os"

	"github.com/yassinebenaid/godump"
)

func main() {
	godump.Dump(os.Stdout)
}

Output:

Example 2.

package main

import (
	"net"

	"github.com/yassinebenaid/godump"
)

func main() {
	godump.Dump(net.Dialer{})
}

Output:

Example 3.

This example shows how recursive pointers are handled.

package main

import (
	"github.com/yassinebenaid/godump"
)

func main() {
	type User struct {
		Name       string
		age        int
		BestFriend *User
	}

	me := User{
		Name: "yassinebenaid",
		age:  22,
	}

    // This creates a ring
	me.BestFriend = &me

	godump.Dump(me)
}

Output:

Example 4.

This example emphasizes how you can generate HTML

package main

import (
	"fmt"
	"net"
	"net/http"

	"github.com/yassinebenaid/godump"
)

// Define your custom style implementation
type CSSColor struct {
	R, G, B int
}

func (c CSSColor) Apply(s string) string {
	return fmt.Sprintf(`<div style="color: rgb(%d, %d, %d); display: inline-block">%s</div>`, c.R, c.G, c.B, s)
}

func main() {

	var d godump.Dumper

	d.Theme = godump.Theme{
		String:        CSSColor{138, 201, 38},// edit the theme to use your implementation
		Quotes:        CSSColor{112, 214, 255},
		Bool:          CSSColor{249, 87, 56},
		Number:        CSSColor{10, 178, 242},
		Types:         CSSColor{0, 150, 199},
		Address:       CSSColor{205, 93, 0},
		PointerTag:    CSSColor{110, 110, 110},
		Nil:           CSSColor{219, 57, 26},
		Func:          CSSColor{160, 90, 220},
		Fields:        CSSColor{189, 176, 194},
		Chan:          CSSColor{195, 154, 76},
		UnsafePointer: CSSColor{89, 193, 180},
		Braces:        CSSColor{185, 86, 86},
	}

	var html = `<pre style="background: #111; padding: 10px; color: white">`
	html += d.Sprint(net.Dialer{})
	html += "<pre>"

    // render it to browsers
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/html")
		fmt.Fprint(w, html)
	})

	http.ListenAndServe(":8000", nil)

}

Output:

For more examples, please take a look at dumper_test along with testdata

Contribution

Please read CONTRIBUTING guidelines

godump's Issues

Is that possible to support loading in-memory structures from files?

like encoding/gob did, but supports private field. I'd like to use this feature to implement something like snapshot testing.

Feature Request: Sdump

spew have spew.Sdump (dump to string) so it would be nice if there's similar one

doesn't work with general named types

type NamedType int

func main() {
	err := godump.Dump(NamedType(0))
	if err != nil {
		panic(err)
	}
}

Show pointer values

Hi!

Looks like right now we are showing the addresses of pointers.

Pointer: *int:0x0000a4010

IMO it would be better to do something like:

Pointer: *int:&55644133

thoughts?