diff --git a/src/cmd/compile/internal/types2/termlist_test.go b/src/cmd/compile/internal/types2/termlist_test.go
index 2f3772ddeb8..ed1330d26fc 100644
--- a/src/cmd/compile/internal/types2/termlist_test.go
+++ b/src/cmd/compile/internal/types2/termlist_test.go
@@ -11,7 +11,7 @@ import (
 
 // maketl makes a term list from a string of the term list.
 func maketl(s string) termlist {
-	s = strings.Replace(s, " ", "", -1)
+	s = strings.ReplaceAll(s, " ", "")
 	names := strings.Split(s, "∪")
 	r := make(termlist, len(names))
 	for i, n := range names {
@@ -20,7 +20,7 @@ func maketl(s string) termlist {
 	return r
 }
 
-func TestTermlistTop(t *testing.T) {
+func TestTermlistAll(t *testing.T) {
 	if !allTermlist.isAll() {
 		t.Errorf("allTermlist is not the set of all types")
 	}
diff --git a/src/go/types/builtins.go b/src/go/types/builtins.go
index 2099a92acb7..a11f3959475 100644
--- a/src/go/types/builtins.go
+++ b/src/go/types/builtins.go
@@ -848,7 +848,6 @@ func makeSig(res Type, args ...Type) *Signature {
 
 // arrayPtrDeref returns A if typ is of the form *A and A is an array;
 // otherwise it returns typ.
-//
 func arrayPtrDeref(typ Type) Type {
 	if p, ok := typ.(*Pointer); ok {
 		if a := asArray(p.base); a != nil {
diff --git a/src/go/types/termlist_test.go b/src/go/types/termlist_test.go
index ba0faff3591..d1fe28f728b 100644
--- a/src/go/types/termlist_test.go
+++ b/src/go/types/termlist_test.go
@@ -11,7 +11,7 @@ import (
 
 // maketl makes a term list from a string of the term list.
 func maketl(s string) termlist {
-	s = strings.Replace(s, " ", "", -1)
+	s = strings.ReplaceAll(s, " ", "")
 	names := strings.Split(s, "∪")
 	r := make(termlist, len(names))
 	for i, n := range names {
@@ -20,9 +20,9 @@ func maketl(s string) termlist {
 	return r
 }
 
-func TestTermlistTop(t *testing.T) {
+func TestTermlistAll(t *testing.T) {
 	if !allTermlist.isAll() {
-		t.Errorf("topTermlist is not top")
+		t.Errorf("allTermlist is not the set of all types")
 	}
 }
 
diff --git a/src/go/types/typestring.go b/src/go/types/typestring.go
index c38cfd42905..452c92f74db 100644
--- a/src/go/types/typestring.go
+++ b/src/go/types/typestring.go
@@ -86,7 +86,6 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 				break
 			}
 		}
-
 		buf.WriteString(t.name)
 
 	case *Array:
@@ -147,6 +146,7 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 	case *Interface:
 		buf.WriteString("interface{")
 		first := true
+		// print explicit interface methods and embedded types
 		for _, m := range t.methods {
 			if !first {
 				buf.WriteString("; ")