Merge pull request #26 from fvosberg/fix-emptyinterfaces

[PATCH] Omit sync package while mocking empty interface

pkg/moq/moq.go

@@ -71,6 +71,7 @@ func (m *Mocker) Mock(w io.Writer, name ...string) error {
 		PackageName: m.pkgName,
 		Imports:     moqImports,
 	}
+	mocksMethods := false
 	for _, pkg := range m.pkgs {
 		i := 0
 		files := make([]*ast.File, len(pkg.Files))
@@ -96,6 +97,7 @@ func (m *Mocker) Mock(w io.Writer, name ...string) error {
 				InterfaceName: n,
 			}
 			for i := 0; i < iiface.NumMethods(); i++ {
+				mocksMethods = true
 				meth := iiface.Method(i)
 				sig := meth.Type().(*types.Signature)
 				method := &method{
@@ -108,6 +110,9 @@ func (m *Mocker) Mock(w io.Writer, name ...string) error {
 			doc.Objects = append(doc.Objects, obj)
 		}
 	}
+	if mocksMethods {
+		doc.Imports = append(doc.Imports, "sync")
+	}
 	for pkgToImport := range m.imports {
 		doc.Imports = append(doc.Imports, pkgToImport)
 	}

pkg/moq/moq_test.go

@@ -224,3 +224,19 @@ func TestDotImports(t *testing.T) {
 		t.Error("contains invalid dot import")
 	}
 }
+
+func TestEmptyInterface(t *testing.T) {
+	m, err := New("testpackages/emptyinterface", "")
+	if err != nil {
+		t.Fatalf("moq.New: %s", err)
+	}
+	var buf bytes.Buffer
+	err = m.Mock(&buf, "Empty")
+	if err != nil {
+		t.Errorf("mock error: %s", err)
+	}
+	s := buf.String()
+	if strings.Contains(s, `"sync"`) {
+		t.Error("contains sync import, although this package isn't used")
+	}
+}

pkg/moq/template.go

@@ -1,7 +1,7 @@
 package moq
 
 // moqImports are the imports all moq files get.
-var moqImports = []string{"sync"}
+var moqImports = []string{}
 
 // moqTemplate is the template for mocked code.
 var moqTemplate = `// Code generated by moq; DO NOT EDIT

pkg/moq/testpackages/emptyinterface/empty.go

@@ -0,0 +1,4 @@
+package emptyinterface
+
+// Empty is an empty interface
+type Empty interface{}