v0.0.260 wmo: fix endless recursion in wmo reflection

goextVersion.go

@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.259"
+const GoextVersion = "0.0.260"
 
-const GoextVersionTimestamp = "2023-09-12T10:48:57+0200"
+const GoextVersionTimestamp = "2023-09-12T11:40:39+0200"

wmo/reflection.go

@@ -25,7 +25,7 @@ func (c *Coll[TData]) EnsureInitializedReflection(v TData) {
 
 	m := make(map[string]fullTypeRef)
 
-	c.initFields("", rval.Type(), m, make([]int, 0))
+	c.initFields("", rval.Type(), m, make([]int, 0), make([]reflect.Type, 0))
 
 	c.implDataTypeMap[rval.Type()] = m
 }
@@ -50,14 +50,13 @@ func (c *Coll[TData]) init() {
 		c.implDataTypeMap = make(map[reflect.Type]map[string]fullTypeRef)
 
 		v := reflect.ValueOf(example)
-		c.initFields("", v.Type(), c.dataTypeMap, make([]int, 0))
+		c.initFields("", v.Type(), c.dataTypeMap, make([]int, 0), make([]reflect.Type, 0))
 
 	}
 
 }
 
-func (c *Coll[TData]) initFields(prefix string, rtyp reflect.Type, m map[string]fullTypeRef, idxarr []int) {
-
+func (c *Coll[TData]) initFields(prefix string, rtyp reflect.Type, m map[string]fullTypeRef, idxarr []int, typesInPath []reflect.Type) {
 	for i := 0; i < rtyp.NumField(); i++ {
 
 		rsfield := rtyp.Field(i)
@@ -91,7 +90,7 @@ func (c *Coll[TData]) initFields(prefix string, rtyp reflect.Type, m map[string]
 		if langext.InArray("inline", bsontags) && rsfield.Type.Kind() == reflect.Struct {
 
 			// pass-through field
-			c.initFields(prefix, rsfield.Type, m, newIdxArr)
+			c.initFields(prefix, rsfield.Type, m, newIdxArr, typesInPath)
 
 		} else {
 
@@ -122,11 +121,25 @@ func (c *Coll[TData]) initFields(prefix string, rtyp reflect.Type, m map[string]
 			}
 
 			if rsfield.Type.Kind() == reflect.Struct {
-				c.initFields(fullKey+".", rsfield.Type, m, newIdxArr)
+				c.initFields(fullKey+".", rsfield.Type, m, newIdxArr, typesInPath)
 			}
 
 			if rsfield.Type.Kind() == reflect.Pointer && rsfield.Type.Elem().Kind() == reflect.Struct {
-				c.initFields(fullKey+".", rsfield.Type.Elem(), m, newIdxArr)
+				innerType := rsfield.Type.Elem()
+
+				// check if there is recursion
+				recursion := false
+				for _, typ := range typesInPath {
+					recursion = recursion || (typ == innerType)
+				}
+
+				if !recursion {
+					// Store all seen types before that deref a pointer to prevent endless recursion
+					newTypesInPath := make([]reflect.Type, len(typesInPath))
+					copy(newTypesInPath, typesInPath)
+					newTypesInPath = append(newTypesInPath, rtyp)
+					c.initFields(fullKey+".", innerType, m, newIdxArr, newTypesInPath)
+				}
 			}
 		}
 

wmo/reflection_test.go

@@ -113,19 +113,25 @@ func TestReflectionGetTokenValueAsMongoType(t *testing.T) {
 
 	type IDType string
 
+	type RecurseiveType struct {
+		Other int             `bson:"other"`
+		Inner *RecurseiveType `bson:"inner"`
+	}
+
 	type TestData struct {
 		ID    IDType    `bson:"_id"`
 		CDate time.Time `bson:"cdate"`
 		Sub   struct {
 			A string `bson:"a"`
 		} `bson:"sub"`
-		SubPtr struct {
+		SubPtr *struct {
 			A string `bson:"a"`
 		} `bson:"subPtr"`
 		Str   string                  `bson:"str"`
 		Ptr   *int                    `bson:"ptr"`
 		Num   int                     `bson:"num"`
 		MDate rfctime.RFC3339NanoTime `bson:"mdate"`
+		Rec   RecurseiveType          `bson:"rec"`
 	}
 
 	coll := W[TestData](&mongo.Collection{})
@@ -149,6 +155,7 @@ func TestReflectionGetTokenValueAsMongoType(t *testing.T) {
 	tst.AssertEqual(t, gtvasmt("hello", "str").(string), "hello")
 	tst.AssertEqual(t, gtvasmt("hello", "sub.a").(string), "hello")
 	tst.AssertEqual(t, gtvasmt("hello", "subPtr.a").(string), "hello")
+	tst.AssertEqual(t, gtvasmt("4", "rec.other").(int), 4)
 	tst.AssertEqual(t, gtvasmt("4", "num").(int), 4)
 	tst.AssertEqual(t, gtvasmt("asdf", "_id").(IDType), "asdf")
 	tst.AssertEqual(t, gtvasmt("", "ptr").(*int), nil)