init

.github/workflows/run-staticcheck.yaml

@@ -20,7 +20,7 @@ jobs:
       fail-fast: false
       matrix:
         os:  ["ubuntu-latest"]
-        go:  ["1.19"]
+        go:  ["1.21"]
 
     runs-on: ${{ matrix.os }}
 

.github/workflows/run-tests.yaml

@@ -20,7 +20,7 @@ jobs:
       fail-fast: false
       matrix:
         os:  ["windows-latest", "ubuntu-latest", "macOS-latest"]
-        go:  ["1.18", "1.19", "1.20"]
+        go:  ["1.21"]
 
     runs-on: ${{ matrix.os }}
 

README.md

@@ -5,22 +5,78 @@
 <a href="https://goreportcard.com/report/github.com/bayashi/witness" title="witness report card" target="_blank"><img src="https://goreportcard.com/badge/github.com/bayashi/witness" alt="witness report card"></a>
 <a href="https://pkg.go.dev/github.com/bayashi/witness" title="Go witness package reference" target="_blank"><img src="https://pkg.go.dev/badge/github.com/bayashi/witness.svg" alt="Go Reference: witness"></a>
 
-`witness` provides 
+`witness` is a test helper to make an evident report on a fail of your test.
 
 ## Usage
 
+Simple case.
+
 ```go
 package main
 
 import (
-    "fmt"
+    "testing"
+
+    w "github.com/bayashi/witness"
 )
 
-func main() {
+func TestExample(t *testing.T) {
+    g := "a\nb\nc"
+    e := "a\nd\nc"
 
+    if g != e {
+        w.Got(g).Expect(e).Fail(t, "Not same")
+    }
 }
 ```
 
+below result will be shown:
+
+```go
+Trace:          /home/usr/go/src/github.com/bayashi/witness/witness_test.go:33
+Fail reason:    Not same
+Type:           Expect:string, Got:string
+Expected:       "a\nd\nc"
+Actually got:   "a\nb\nc"
+```
+
+It's able to show more additional info:
+
+```go
+w.Got(g).Expect(e).ShowMore().Fail(t, "Not same")
+```
+
+And then,
+
+```go
+Trace:          /home/usr/go/src/github.com/bayashi/witness/witness_test.go:41
+Fail reason:    Not same
+Type:           Expect:string, Got:string
+Expected:       "a\nd\nc"
+Actually got:   "a\nb\nc"
+Diff details:   --- Expected
+                +++ Actually got
+                @@ -1,3 +1,3 @@
+                 a
+                -d
+                +b
+                 c
+Raw Expect:     ---
+                a
+                d
+                c
+                ---
+Raw Got:        ---
+                a
+                b
+                c
+                ---
+```
+
+So easy and fair, isn't this?
+
+You shouldn't need to spend your time anymore to show fail report.
+
 ## Installation
 
 ```cmd
@@ -34,3 +90,11 @@ MIT License
 ## Author
 
 Dai Okabayashi: https://github.com/bayashi
+
+## See Also
+
+https://github.com/bayashi/actually
+
+## Special Thanks To
+
+https://github.com/stretchr/testify

diff/diff.go

@@ -0,0 +1,104 @@
+package diff
+
+import (
+	"reflect"
+	"time"
+
+	"github.com/davecgh/go-spew/spew"
+	"github.com/pmezard/go-difflib/difflib"
+)
+
+var spewConfig = spew.ConfigState{
+	Indent:                  " ",
+	DisablePointerAddresses: true,
+	DisableCapacities:       true,
+	SortKeys:                true,
+	DisableMethods:          true,
+	MaxDepth:                10,
+}
+
+var spewConfigStringerEnabled = spew.ConfigState{
+	Indent:                  " ",
+	DisablePointerAddresses: true,
+	DisableCapacities:       true,
+	SortKeys:                true,
+	MaxDepth:                10,
+}
+
+// Diff method returns diff text of 2 testing objects
+func Diff(expectv any, gotv any) string {
+	e, g := pre(expectv, gotv)
+	if e == "" && g == "" {
+		return ""
+	}
+
+	return getDiff(e, g, "Expected", "Actually got")
+}
+
+// DiffSimple method returns diff text of 2 objects as "a and b"
+func DiffSimple(av any, bv any) string {
+	a, b := pre(av, bv)
+	if a == "" && b == "" {
+		return ""
+	}
+
+	return getDiff(a, b, "a", "b")
+}
+
+func pre(expectv any, gotv any) (string, string) {
+	if expectv == nil || gotv == nil {
+		return "", ""
+	}
+
+	et, ek := typeAndKind(expectv)
+	gt, _ := typeAndKind(gotv)
+
+	if et != gt {
+		return "", ""
+	}
+
+	if ek != reflect.Struct && ek != reflect.Map && ek != reflect.Slice && ek != reflect.Array && ek != reflect.String {
+		return "", ""
+	}
+
+	var e, g string
+
+	switch et {
+	case reflect.TypeOf(""):
+		e = reflect.ValueOf(expectv).String()
+		g = reflect.ValueOf(gotv).String()
+	case reflect.TypeOf(time.Time{}):
+		e = spewConfigStringerEnabled.Sdump(expectv)
+		g = spewConfigStringerEnabled.Sdump(gotv)
+	default:
+		e = spewConfig.Sdump(expectv)
+		g = spewConfig.Sdump(gotv)
+	}
+
+	return e, g
+}
+
+func typeAndKind(v any) (reflect.Type, reflect.Kind) {
+	t := reflect.TypeOf(v)
+	k := t.Kind()
+
+	if k == reflect.Ptr {
+		t = t.Elem()
+		k = t.Kind()
+	}
+	return t, k
+}
+
+func getDiff(e string, g string, fromFile string, toFile string) string {
+	diff, _ := difflib.GetUnifiedDiffString(difflib.UnifiedDiff{
+		A:        difflib.SplitLines(e),
+		B:        difflib.SplitLines(g),
+		FromFile: fromFile,
+		FromDate: "",
+		ToFile:   toFile,
+		ToDate:   "",
+		Context:  1,
+	})
+
+	return diff
+}

diff/diff_test.go

@@ -0,0 +1,87 @@
+package diff
+
+import (
+	"testing"
+	"time"
+)
+
+func TestDiffStruct(t *testing.T) {
+	type S struct {
+		id   int
+		name string
+	}
+
+	a := &S{
+		id:   123,
+		name: "aiko",
+	}
+	b := &S{
+		id:   124,
+		name: "eiko",
+	}
+
+	got := "\n" + Diff(a, b) // "\n" is for comparing to heredoc.
+	expect := `
+--- Expected
++++ Actually got
+@@ -1,4 +1,4 @@
+ (*diff.S)({
+- id: (int) 123,
+- name: (string) (len=4) "aiko"
++ id: (int) 124,
++ name: (string) (len=4) "eiko"
+ })
+`
+	if got != expect {
+		t.Errorf("Diff was wrong.\n[Got]\n%s\n\n[Expect]\n%s\n", got, expect)
+	}
+}
+
+func TestDiffString(t *testing.T) {
+	a := "beer"
+	b := "deer"
+
+	got := "\n" + Diff(a, b)
+	expect := `
+--- Expected
++++ Actually got
+@@ -1 +1 @@
+-beer
++deer
+`
+	if got != expect {
+		t.Errorf("Diff was wrong.\n[Got]\n%s\n\n[Expect]\n%s\n", got, expect)
+	}
+}
+
+func TestDiffTime(t *testing.T) {
+	a := time.Date(2023, 4, 23, 0, 0, 0, 0, time.UTC)
+	b := time.Date(2023, 4, 24, 0, 0, 0, 0, time.UTC)
+
+	got := "\n" + Diff(a, b)
+	expect := `
+--- Expected
++++ Actually got
+@@ -1,2 +1,2 @@
+-(time.Time) 2023-04-23 00:00:00 +0000 UTC
++(time.Time) 2023-04-24 00:00:00 +0000 UTC
+ 
+` // What is last space? It would be created by difflib.GetUnifiedDiffString?? Anyway, I ignore :-)
+	if got != expect {
+		t.Errorf("Diff was wrong.\n[Got]\n%#v\n\n[Expect]\n%#v\n", got, expect)
+	}
+}
+
+func TestDiffNil(t *testing.T) {
+	if Diff(nil, nil) != "" {
+		t.Error("<nil> input should be blank string")
+	}
+
+	if Diff(1, "string") != "" {
+		t.Error("Input values should be same type")
+	}
+
+	if Diff(1, 2) != "" {
+		t.Error("NOT supported int type")
+	}
+}

go.mod

@@ -1,3 +1,8 @@
 module github.com/bayashi/witness
 
-go 1.18
+go 1.21
+
+require (
+	github.com/davecgh/go-spew v1.1.1
+	github.com/pmezard/go-difflib v1.0.0
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=