go-diff is a Go package that aims to provide functions to calculate differences between two Go structures. The result is presented as a generic map containing old and new values. See the documentation for more details and examples.

go get -u github.com/e-XpertSolutions/go-diff/diff

package main

import (
  "fmt"
  "log"

  "github.com/e-XpertSolutions/go-diff/diff"
)

type StructA struct {
  SomeInt int
  B *StructB
}

type StructB struct {
  SomeVal string
  SomeFloat float32
}

func main() {
  a1 := StructA{
    SomeInt: 42,
    B: &StructB{ SomeVal: "Foo", SomeFloat: 123.456 },
  }
  a2 := StructA{
    SomeInt: 24,
    B: &StructB{ SomeVal: "Bar", SomeFloat: 123.4567 },
  }

  d, err :=  diff.Compute(a1, a2)
  if err != nil {
    log.Fatal(err)
  }

  fmt.Println(string(d.PrettyJSON()))

  // Output:
  // {
  //   "B": {
  //     "SomeVal": {
  //       "old_value": "Foo",
  //       "new_value": "Bar",
  //       "type": "MOD"
  //     }
  //   },
  //   "SomeInt": {
  //     "old_value": 42,
  //     "new_value": 24,
  //     "type": "MOD"
  //   }
  // }
}

• Basic types (int, float, bool and string): Basic types are directly compared using language defined operators (== and !=).
• Pointers: The values pointed are compared, not the addresses.
• Structures: Structures are compared recursively. If they do not contain any exported fields, the structures are compared as strings.
• Slices and arrays: Slices and arrays are compared row by row.
• Maps: Maps are not yet supported.

• Add support for map types
• Add support for complex numbers
• Allow the user to override comparisons through an interface
• Add an option to limit the depth of the comparisons
• Better support for slices/arrays comparison
• More tests and benchmarks
• Add XML serialization

We appreciate any form of contribution (feature request, bug report, pull request, ...). We have no special requirements for Pull Request, just follow the standard GitHub way.

The sources are release under a BSD 3-Clause License. The full terms of that license can be found in LICENSE file of this repository.