fix(generator): Unmarshaling of fixed sized custom types is generated…

… incorrectly. (ferranbt#152)

* fix

* update control flow

* bug fix

* add test case

---------

Co-authored-by: ocnc <anocpublic@gmail.com>

sszgen/generator/generator.go

@@ -210,6 +210,8 @@ func detectImports(v *Value) string {
 		ref = v.ref
 	case TypeList, TypeVector:
 		ref = v.e.ref
+	case TypeBytes:
+		ref = v.ref
 	default:
 		ref = v.ref
 	}
@@ -223,7 +225,6 @@ func (v *Value) objRef() string {
 	if v.ref == "" {
 		return v.obj
 	}
-
 	valuesImported = append(valuesImported, v)
 	return v.ref + "." + v.obj
 }
@@ -322,7 +323,6 @@ type env struct {
 
 func (e *env) generateOutputEncodings(output string) (map[string]string, error) {
 	out := map[string]string{}
-
 	keys := make([]string, 0, len(e.order))
 	for k := range e.order {
 		keys = append(keys, k)
@@ -444,6 +444,7 @@ func (e *env) print(order []string) (string, bool, error) {
 			// require the sszgen functions.
 			continue
 		}
+
 		objs = append(objs, &Obj{
 			HashTreeRoot: e.hashTreeRoot(name, obj),
 			GetTree:      e.getTree(name, obj),

sszgen/generator/unmarshal.go

@@ -349,18 +349,21 @@ func (v *Value) createSlice(useNumVariable bool) string {
 		return fmt.Sprintf("::.%s = make([]%s%s, %s)", v.name, ptr, v.e.objRef(), size)
 
 	case TypeBytes:
-		// [][]byte
 		if v.c {
 			return ""
 		}
+
+		// Check for a type alias.
+		ref := v.e.objRef()
+		if ref != "" {
+			return fmt.Sprintf("::.%s = make([]%s, %s)", v.name, ref, size)
+		}
+
 		if v.e.c {
 			return fmt.Sprintf("::.%s = make([][%d]byte, %s)", v.name, v.e.s, size)
 		}
-		ref := v.e.objRef()
-		if ref == "" {
-			ref = "[]byte"
-		}
-		return fmt.Sprintf("::.%s = make([]%s, %s)", v.name, ref, size)
+
+		return fmt.Sprintf("::.%s = make([][]byte, %s)", v.name, size)
 
 	default:
 		panic(fmt.Sprintf("create not implemented for %s type %s", v.name, v.e.t.String()))

sszgen/testcases/pr_152.go

@@ -0,0 +1,11 @@
+package testcases
+
+// Data152 is a byte array with 48 elements
+//
+//go:generate go run ../main.go --path pr_152.go
+type Data152 [48]byte
+
+// PR1512 is a struct with a Data152 field
+type PR1512 struct {
+	D []Data152 `ssz-max:"32"`
+}