yazgazan/jaydiff

package diff

import (
    "encoding/json"
    "fmt"

    "github.com/fatih/color"
)

// Output is used to configure the output of the Strings and StringIndent functions.
type Output struct {
    Indent     string
    ShowTypes  bool
    Colorized  bool
    JSON       bool
    JSONValues bool
}

type colorFn func(format string, a ...interface{}) string

var whiteFn colorFn = nil

func (o Output) red(v interface{}) string {
    return o.applyColor(v, color.RedString)
}

func (o Output) green(v interface{}) string {
    return o.applyColor(v, color.GreenString)
}

func (o Output) white(v interface{}) string {
    return o.applyColor(v, whiteFn)
}

func (o Output) applyColor(v interface{}, fn colorFn) string {
    var s string

    switch {
    default:
        s = fmt.Sprintf("%v", v)
    case o.ShowTypes:
        s = fmt.Sprintf("%T %v", v, v)
    case o.JSONValues:
        s = jsonString(v)
    }

    if !o.Colorized || fn == nil {
        return s
    }

    return fn("%s", s)
}

func (o Output) typ(v interface{}) string {
    if o.ShowTypes {
        return fmt.Sprintf("%T ", v)
    }

    return ""
}

func newLineSeparatorString(conf Output) string {
    if conf.JSON {
        return ",\n"
    }

    return "\n"
}

func jsonString(v interface{}) string {
    b, err := json.Marshal(v)
    if err != nil {
        panic(fmt.Errorf("unexpected error marshaling value: %s", err))
    }

    return string(b)
}