added functional options for auto mapping

.github/workflows/go.yml

@@ -18,7 +18,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v4
       with:
-        go-version: '1.20'
+        go-version: '1.21'
 
     - name: Build
       run: go build -v ./...

auto.go

@@ -2,6 +2,7 @@ package gomapper
 
 import (
 	"reflect"
+	"slices"
 
 	"github.com/insei/fmap/v3"
 )
@@ -33,6 +34,9 @@ func AutoRoute[TSource, TDest any | []any](opts ...Option) error {
 			if destFld.GetType() != srcFld.GetType() {
 				continue
 			}
+			if slices.Contains(opt.Excluded, srcFld) {
+				continue
+			}
 			if err := setFieldRecursive(srcFld, destFld, source, dest); err != nil {
 				return err
 			}

auto_test.go

@@ -9,6 +9,7 @@ import (
 )
 
 type AutoMappingStructSource struct {
+	Age          int
 	Name         string
 	Time         time.Time
 	UUID         uuid.UUID
@@ -18,10 +19,11 @@ type AutoMappingStructSource struct {
 }
 
 type AutoMappingStructDest struct {
+	UUID         uuid.UUID
+	Age          int
 	Name         string
 	SecondName   string
 	Time         time.Time
-	UUID         uuid.UUID
 	PtrTime      *time.Time
 	PtrUUID      *uuid.UUID
 	NestedStruct NestedStructDest
@@ -70,15 +72,24 @@ func TestAutoRoute(t *testing.T) {
 			dest.PtrTime = &timeNow
 		}
 		dest.Time = timeNow
-	}))
+	}),
+		WithFieldSkip(func(dest *AutoMappingStructSource) any {
+			return &dest.UUID
+		}),
+		WithFieldSkip(func(dest *AutoMappingStructSource) any {
+			return &dest.Age
+		}),
+	)
 	t.Run("Auto route with options", func(t *testing.T) {
-		source := &AutoMappingStructSource{Name: "Test1"}
+		source := &AutoMappingStructSource{UUID: uuid.New(), Name: "Test1", Age: 25}
 		dest, err := MapTo[AutoMappingStructDest](source)
 		assert.NoError(t, err)
 		assert.Equal(t, source.Name, dest.Name)
 		assert.Equal(t, "Test2", dest.SecondName)
 		assert.Equal(t, timeNow, *dest.PtrTime)
 		assert.Equal(t, timeNow, dest.Time)
+		assert.Equal(t, 0, dest.Age)
+		assert.Equal(t, uuid.Nil, dest.UUID)
 	})
 	t.Run("Auto mapping struct fields", func(t *testing.T) {
 		source := &AutoMappingStructSource{

go.mod

@@ -1,10 +1,10 @@
 module github.com/insei/gomapper
 
-go 1.18
+go 1.21
 
 require (
 	github.com/google/uuid v1.6.0
-	github.com/insei/fmap/v3 v3.0.0
+	github.com/insei/fmap/v3 v3.1.2
 	github.com/stretchr/testify v1.9.0
 )
 

go.sum

@@ -2,8 +2,8 @@ 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/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/insei/fmap/v3 v3.0.0 h1:BpRsFgQ2nt5tl/8tzp6y+MWIAJhqCTeKBHC56L/Um30=
-github.com/insei/fmap/v3 v3.0.0/go.mod h1:Kk0gs7nKb4E/JycKJFnrsX5hlyBBe0yetGKFCJG0vzk=
+github.com/insei/fmap/v3 v3.1.2 h1:ZBr+WiZpIxFNeMo2X4QOST4AFl0sGAkG+EO08Ved3bY=
+github.com/insei/fmap/v3 v3.1.2/go.mod h1:Kk0gs7nKb4E/JycKJFnrsX5hlyBBe0yetGKFCJG0vzk=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=

options.go

@@ -1,11 +1,20 @@
 package gomapper
 
+import (
+	"github.com/insei/fmap/v3"
+)
+
 type withFuncOption[TSource, TDest any] struct {
 	fn func(TSource, *TDest)
 }
 
+type withFieldSkip[TDest any] struct {
+	field fmap.Field
+}
+
 type options struct {
-	Fns []any
+	Fns      []any
+	Excluded []fmap.Field
 }
 
 type Option interface {
@@ -16,6 +25,31 @@ func (a withFuncOption[TSource, TDest]) apply(opts *options) {
 	opts.Fns = append(opts.Fns, a.fn)
 }
 
+func (a withFieldSkip[TDest]) apply(opts *options) {
+	if opts.Excluded == nil {
+		opts.Excluded = make([]fmap.Field, 0)
+	}
+	opts.Excluded = append(opts.Excluded, a.field)
+}
+
 func WithFunc[TSource, TDest any](fn func(TSource, *TDest)) Option {
 	return &withFuncOption[TSource, TDest]{fn: fn}
 }
+
+func WithFieldSkip[TSource any](fn func(*TSource) any) Option {
+	source := new(TSource)
+
+	storage, err := fmap.GetFrom(source)
+	if err != nil {
+		panic(err)
+	}
+
+	fieldPtr := fn(source)
+
+	field, err := storage.GetFieldByPtr(source, fieldPtr)
+	if err != nil {
+		panic(err)
+	}
+
+	return &withFieldSkip[TSource]{field: field}
+}