messagediff 
A library for doing diffs of arbitrary Golang structs.
Forked and modified from d4l3k/messagediff.
If the unsafe package is available messagediff will diff unexported fields in addition to exported fields. This is primarily used for testing purposes as it allows for providing informative error messages.
Optionally, fields in structs can be tagged as testdiff:"ignore" to make
messagediff skip it when doing the comparison.
The results of PrettyDiff are formatted and colorized to match the diff format produced by git.
Example Usage
In a normal file:
package main
import "github.com/Mrmann87/messagediff"
type someStruct struct {
A, b int
C []int
}
func main() {
a := someStruct{1, 2, []int{1}}
b := someStruct{1, 3, []int{1, 2}}
diff, equal := messagediff.PrettyDiff(a, b)
/*
diff =
---a.b
+++b.b
-2
+3
---a.C[1]
+++b.C[1]
+2
equal =
false
*/
}In a test:
import "github.com/Mrmann87/messagediff"
...
type someStruct struct {
A, b int
C []int
}
func TestSomething(t *testing.T) {
want := someStruct{1, 2, []int{1}}
got := someStruct{1, 3, []int{1, 2}}
if diff, equal := messagediff.PrettyDiff(want, got); !equal {
t.Errorf("Something() = %#v\n%s", got, diff)
}
}To ignore a field in a struct, just annotate it with testdiff:"ignore" like this:
package main
import "github.com/Mrmann87/messagediff"
type someStruct struct {
A int
B int `testdiff:"ignore"`
}
func main() {
a := someStruct{1, 2}
b := someStruct{1, 3}
diff, equal := messagediff.PrettyDiff(a, b)
/*
diff = ""
equal = true
*/
}See the DeepDiff function for using the diff results programmatically.
License
Copyright (c) 2015 Tristan Rice rice@fn.lc
messagediff is licensed under the MIT license. See the LICENSE file for more information.
bypass.go and bypasssafe.go are borrowed from go-spew and have a seperate copyright notice.