Customizability (transform) (#2)

deepequal.go

@@ -19,10 +19,12 @@ type visit struct {
 	typ reflect.Type
 }
 
-const maxDepth = 1_000
-
-func (teq Teq) deepValueEqual(v1, v2 reflect.Value, visited map[visit]bool, depth int) bool {
-	if depth > maxDepth {
+func (teq Teq) deepValueEqual(
+	v1, v2 reflect.Value,
+	visited map[visit]bool,
+	depth int,
+) bool {
+	if depth > teq.MaxDepth {
 		panic("maximum depth exceeded")
 	}
 	if !v1.IsValid() || !v2.IsValid() {
@@ -32,6 +34,15 @@ func (teq Teq) deepValueEqual(v1, v2 reflect.Value, visited map[visit]bool, dept
 		return false
 	}
 
+	tr, ok := teq.transforms[v1.Type()]
+	if ok {
+		t1 := tr(v1)
+		t2 := tr(v2)
+		newTeq := New()
+		newTeq.MaxDepth = teq.MaxDepth
+		return newTeq.deepValueEqual(t1, t2, visited, depth)
+	}
+
 	if hard(v1.Kind()) {
 		if v1.CanAddr() && v2.CanAddr() {
 			addr1 := v1.Addr().UnsafePointer()
@@ -134,7 +145,7 @@ func pointerEq(teq Teq, v1, v2 reflect.Value, nx next) bool {
 
 func structEq(teq Teq, v1, v2 reflect.Value, nx next) bool {
 	for i, n := 0, v1.NumField(); i < n; i++ {
-		if !nx(v1.Field(i), v2.Field(i)) {
+		if !nx(field(v1, i), field(v2, i)) {
 			return false
 		}
 	}

misc.go

@@ -0,0 +1,16 @@
+package teq
+
+import (
+	"reflect"
+)
+
+func field(v reflect.Value, idx int) reflect.Value {
+	f1 := v.Field(idx)
+	if f1.CanAddr() {
+		return f1
+	}
+	vc := reflect.New(v.Type()).Elem()
+	vc.Set(v)
+	rf := vc.Field(idx)
+	return reflect.NewAt(rf.Type(), rf.Addr().UnsafePointer()).Elem()
+}

teq.go

@@ -4,13 +4,25 @@ import (
 	"reflect"
 )
 
-type Teq struct{}
+type Teq struct {
+	MaxDepth int
+
+	transforms map[reflect.Type]func(reflect.Value) reflect.Value
+}
+
+func New() Teq {
+	return Teq{
+		MaxDepth: 1_000,
+
+		transforms: make(map[reflect.Type]func(reflect.Value) reflect.Value),
+	}
+}
 
 func (teq Teq) Equal(t TestingT, expected, actual any) bool {
 	t.Helper()
 	defer func() {
 		if r := recover(); r != nil {
-			t.Errorf("panic: %v", r)
+			t.Errorf("panic in github.com/seiyab/teq. please report issue. message: %v", r)
 		}
 	}()
 	ok := teq.equal(expected, actual)
@@ -20,6 +32,44 @@ func (teq Teq) Equal(t TestingT, expected, actual any) bool {
 	return ok
 }
 
+func (teq Teq) NotEqual(t TestingT, expected, actual any) bool {
+	t.Helper()
+	defer func() {
+		if r := recover(); r != nil {
+			t.Errorf("panic in github.com/seiyab/teq. please report issue. message: %v", r)
+		}
+	}()
+	ok := !teq.equal(expected, actual)
+	if !ok {
+		if reflect.DeepEqual(expected, actual) {
+			t.Error("reflect.DeepEqual(expected, actual) == true.")
+		} else {
+			t.Errorf("expected %v != %v", expected, actual)
+			t.Log("reflect.DeepEqual(expected, actual) == false. maybe transforms made them equal.")
+		}
+	}
+	return ok
+
+}
+
+func (teq *Teq) AddTransform(transform any) {
+	ty := reflect.TypeOf(transform)
+	if ty.Kind() != reflect.Func {
+		panic("transform must be a function")
+	}
+	if ty.NumIn() != 1 {
+		panic("transform must have only one argument")
+	}
+	if ty.NumOut() != 1 {
+		panic("transform must have only one return value")
+	}
+	trValue := reflect.ValueOf(transform)
+	reflectTransform := func(v reflect.Value) reflect.Value {
+		return trValue.Call([]reflect.Value{v})[0]
+	}
+	teq.transforms[ty.In(0)] = reflectTransform
+}
+
 func (teq Teq) equal(x, y any) bool {
 	if x == nil || y == nil {
 		return x == y
@@ -29,5 +79,9 @@ func (teq Teq) equal(x, y any) bool {
 	if v1.Type() != v2.Type() {
 		return false
 	}
-	return teq.deepValueEqual(v1, v2, make(map[visit]bool), 0)
+	return teq.deepValueEqual(
+		v1, v2,
+		make(map[visit]bool),
+		0,
+	)
 }

teq_customized_test.go

@@ -0,0 +1,55 @@
+package teq_test
+
+import (
+	"reflect"
+	"testing"
+	"time"
+
+	"github.com/seiyab/teq"
+)
+
+func TestEqual_Customized(t *testing.T) {
+	t.Run("time.Time", func(t *testing.T) {
+		defaultTeq := teq.New()
+		customizedTeq := teq.New()
+		customizedTeq.AddTransform(utc)
+
+		secondsEastOfUTC := int((8 * time.Hour).Seconds())
+		beijing := time.FixedZone("Beijing Time", secondsEastOfUTC)
+		d1 := time.Date(2000, 2, 1, 12, 30, 0, 0, time.UTC)
+		d2 := time.Date(2000, 2, 1, 20, 30, 0, 0, beijing)
+
+		defaultTeq.NotEqual(t, d1, d2)
+		customizedTeq.Equal(t, d1, d2)
+		if reflect.DeepEqual(d1, d2) {
+			t.Error("expected d1 != d2, got d1 == d2 with reflect.DeepEqual")
+		}
+
+		type twoDates struct {
+			d1 time.Time
+			d2 time.Time
+		}
+		dt1 := twoDates{d1, d2}
+		dt2 := twoDates{d2, d1}
+
+		defaultTeq.NotEqual(t, dt1, dt2)
+		customizedTeq.Equal(t, dt1, dt2)
+
+		if reflect.DeepEqual(dt1, dt2) {
+			t.Error("expected dt1 != dt2, got dt1 == dt2 with reflect.DeepEqual")
+		}
+
+		t.Skip("slice is not supported yet")
+		ds1 := []time.Time{d1, d1, d2}
+		ds2 := []time.Time{d2, d1, d1}
+		defaultTeq.NotEqual(t, ds1, ds2)
+		customizedTeq.Equal(t, ds1, ds2)
+		if reflect.DeepEqual(ds1, ds2) {
+			t.Error("expected ds1 != ds2, got ds1 == ds2 with reflect.DeepEqual")
+		}
+	})
+}
+
+func utc(d time.Time) time.Time {
+	return d.UTC()
+}

teq_test.go → teq_default_test.go

@@ -20,7 +20,7 @@ type group struct {
 }
 
 func TestEqual(t *testing.T) {
-	assert := teq.Teq{}
+	assert := teq.New()
 
 	groups := []group{
 		{"primitives", primitives()},
@@ -43,14 +43,23 @@ func TestEqual(t *testing.T) {
 						}
 						t.Fatalf("expected %d errors, got %d", len(test.expected), len(mt.errors))
 					}
-					if test.pendingFormat {
-						return
+
+					if !test.pendingFormat {
+						for i, e := range test.expected {
+							if mt.errors[i] != e {
+								t.Errorf("expected %q, got %q at i = %d", e, mt.errors[i], i)
+							}
+						}
 					}
-					for i, e := range test.expected {
-						if mt.errors[i] != e {
-							t.Errorf("expected %q, got %q at i = %d", e, mt.errors[i], i)
+
+					{
+						mt := &mockT{}
+						assert.NotEqual(mt, test.a, test.b)
+						if (len(mt.errors) > 0) == (len(test.expected) > 0) {
+							t.Errorf("expected (len(mt.errors) > 0) = %t, got %t", len(test.expected) > 0, len(mt.errors) > 0)
 						}
 					}
+
 				})
 			}
 		})

testingt.go

@@ -4,7 +4,9 @@ import "testing"
 
 type TestingT interface {
 	Helper()
+	Error(args ...interface{})
 	Errorf(format string, args ...interface{})
+	Log(args ...interface{})
 }
 
 var _ TestingT = &testing.T{}

testingt_test.go

@@ -14,6 +14,12 @@ var _ teq.TestingT = &mockT{}
 
 func (t *mockT) Helper() {}
 
+func (t *mockT) Error(args ...interface{}) {
+	t.errors = append(t.errors, fmt.Sprint(args...))
+}
+
 func (t *mockT) Errorf(format string, args ...interface{}) {
 	t.errors = append(t.errors, fmt.Sprintf(format, args...))
 }
+
+func (t *mockT) Log(args ...interface{}) {}