Add StructToStruct

go.mod

@@ -3,6 +3,7 @@ module git.gsuntres.com/general/commons
 go 1.25.0
 
 require (
+	github.com/go-viper/mapstructure/v2 v2.5.0
 	github.com/ianlancetaylor/jsonschema v0.0.0-20251021232724-46ecbf32a0a5
 	go.mongodb.org/mongo-driver/v2 v2.5.0
 )

go.sum

@@ -1,5 +1,7 @@
 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/go-viper/mapstructure/v2 v2.5.0 h1:vM5IJoUAy3d7zRSVtIwQgBj7BiWtMPfmPEgAXnvj1Ro=
+github.com/go-viper/mapstructure/v2 v2.5.0/go.mod h1:oJDH3BJKyqBA2TXFhDsKDGDTlndYOZ6rGS0BRZIxGhM=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/ianlancetaylor/jsonschema v0.0.0-20251021232724-46ecbf32a0a5 h1:x2QxKV4w/sBEwwUUmBH/8cFjeOBZqwaB5dz5rcuFspU=

struct.go

@@ -5,9 +5,14 @@ import (
 	"reflect"
 	"strings"
 
+	"github.com/go-viper/mapstructure/v2"
 	"go.mongodb.org/mongo-driver/v2/bson"
 )
 
+func StructToStruct(source any, target any) {
+	mapstructure.Decode(source, &target)
+}
+
 // StructToMapRecursive given a struct or a primitive will return the equivalent
 // map[string]any of the struct or the primitive as is.
 func StructToMapRecursive(obj any) any {

struct_test.go

@@ -4,6 +4,28 @@ import (
   "testing"
 )
 
+func TestStructToStruct(t *testing.T) {
+  type O struct {
+    Name string
+    Age int
+    Active bool
+  }
+
+  o := &O{
+    Name: "Nick",
+    Age: 15,
+    Active: true,
+  }
+
+  var oo O
+
+  StructToStruct(o, &oo)
+
+  if oo.Name != "Nick" || oo.Age != 15 || !oo.Active {
+    t.Fatalf("failed to copy %v", oo)
+  }
+}
+
 func TestStructToMapRecursive(t *testing.T) {
   type O struct {
     Name string