fix(bigquery): avoid stack overflow on query param with recursive typ…

…es (#6890)

Resolves #6884

bigquery/params.go

@@ -21,6 +21,7 @@ import (
 	"math/big"
 	"reflect"
 	"regexp"
+	"strings"
 	"time"
 
 	"cloud.google.com/go/civil"
@@ -380,6 +381,12 @@ func paramType(t reflect.Type, v reflect.Value) (*bq.QueryParameterType, error)
 			return nil, err
 		}
 		for _, f := range fields {
+			prefixes := []string{"*", "[]"} // check pointer and arrays
+			for _, prefix := range prefixes {
+				if strings.TrimPrefix(t.String(), prefix) == strings.TrimPrefix(f.Type.String(), prefix) {
+					return nil, fmt.Errorf("bigquery: Go type %s cannot be represented as a parameter due to an attribute cycle/recursion detected", t)
+				}
+			}
 			pt, err := paramType(f.Type, v)
 			if err != nil {
 				return nil, err

bigquery/params_test.go

@@ -282,10 +282,46 @@ func TestParamType(t *testing.T) {
 		}
 	}
 }
-
 func TestParamTypeErrors(t *testing.T) {
 	for _, val := range []interface{}{
-		nil, uint(0), new([]int), make(chan int),
+		nil, uint(0), new([]int), make(chan int), map[string]interface{}{},
+	} {
+		_, err := paramType(reflect.TypeOf(val), reflect.ValueOf(val))
+		if err == nil {
+			t.Errorf("%v (%T): got nil, want error", val, val)
+		}
+	}
+
+	type recArr struct {
+		RecArr []recArr
+	}
+	type recMap struct {
+		RecMap map[string]recMap
+	}
+	queryParam := QueryParameterValue{
+		StructValue: map[string]QueryParameterValue{
+			"nested": {
+				Type: StandardSQLDataType{
+					TypeKind: "STRING",
+				},
+				Value: "TEST",
+			},
+		},
+	}
+	standardSQL := StandardSQLDataType{
+		ArrayElementType: &StandardSQLDataType{
+			TypeKind: "NUMERIC",
+		},
+	}
+	recursiveArr := recArr{
+		RecArr: []recArr{},
+	}
+	recursiveMap := recMap{
+		RecMap: map[string]recMap{},
+	}
+	// Recursive structs
+	for _, val := range []interface{}{
+		queryParam, standardSQL, recursiveArr, recursiveMap,
 	} {
 		_, err := paramType(reflect.TypeOf(val), reflect.ValueOf(val))
 		if err == nil {