This library is compatible with Go 1.17+

Please refer to CHANGELOG.md if you encounter breaking changes.

• Motivation
• Usage
• Contribution
• License

The goal of this library is to both produce diff and patch for arbitrary data structure in GoLang in performant manner

Other project for diffing golang structures and values:

• r3labs/diff

See 3rd party differ performance comparison.

• Benchmark

package godiff_test

import (
	"fmt"
	"github.com/viant/godiff"
	"log"
	"reflect"
	"testing"
)

type Flag struct {
	Value int
}
type Record struct {
	Id        int
	Name      string
	Dep       *Record
	Transient string `diff:"-"`
	Flags     []Flag
}

//ExampleNew shows basic differ usage
func ExampleNew() {

    record1 := &Record{
    Id:    1,
    Name:  "Rec1",
    Flags: []Flag{{Value: 3}, {Value: 15}},
    }
    
    record2 := &Record{
    Id:    2,
    Name:  "Rec1",
    Dep:   &Record{Id: 10},
    Flags: []Flag{{Value: 12}},
    }
    
    diff, err := godiff.New(reflect.TypeOf(record1), reflect.TypeOf(record2))
    if err != nil {
    log.Fatal(err)
    }
    changeLog := diff.Diff(record1, record2)
    fmt.Println(changeLog.String())
}

Supported tags:

• name - optional name in the change log
• indexBy - index elements before comparing
• sort - sort elements before comparing
• whitespace - remove specified whitespace chars when converting string to list or map
• pairSeparator - pair separator to convert string to a map comparison
• pairDelimiter - pair delimiter
• itemSeparator - item separator to convert string to a slice comparison
• '-' (ignore)

Work in progress tag:

• timeLayout
• precision

• WithTagName
• WithRegistry
• NullifyEmpty
• WithConfig

• WithPresence
• WithShallow

GoDiff is around 5x faster than s3lab diff.

pkg: github.com/viant/godiff/bench
cpu: Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
Benchmark_GoDiff
Benchmark_GoDiff-16       	 1432188	       815.9 ns/op	     768 B/op	      14 allocs/op
Benchmark_S3LabDiff
Benchmark_S3LabDiff-16    	  288633	      4531 ns/op	    2262 B/op	      42 allocs/op

godiff is an open source project and contributors are welcome!

See TODO list

Library Author: Adrian Witas