making it Windows compatible

mockgen/parse.go

@@ -562,7 +562,8 @@ func parsePackageImport(srcDir string) (string, error) {
 		for {
 			dat, err := ioutil.ReadFile(filepath.Join(currentDir, "go.mod"))
 			if os.IsNotExist(err) {
-				if currentDir == "/" {
+				if currentDir == filepath.Dir(currentDir) {
+					// at the root
 					break
 				}
 				currentDir = filepath.Dir(currentDir)
@@ -571,17 +572,17 @@ func parsePackageImport(srcDir string) (string, error) {
 				return "", err
 			}
 			modulePath := modfile.ModulePath(dat)
-			return filepath.Join(modulePath, strings.TrimPrefix(srcDir, currentDir)), nil
+			return filepath.ToSlash(filepath.Join(modulePath, strings.TrimPrefix(srcDir, currentDir))), nil
 		}
 	}
 	// fall back to GOPATH mode
 	goPath := os.Getenv("GOPATH")
 	if goPath == "" {
 		return "", fmt.Errorf("GOPATH is not set")
 	}
-	sourceRoot := filepath.Join(goPath, "src") + "/"
+	sourceRoot := filepath.Join(goPath, "src") + string(os.PathSeparator)
 	if !strings.HasPrefix(srcDir, sourceRoot) {
 		return "", errOutsideGoPath
 	}
-	return strings.TrimPrefix(srcDir, sourceRoot), nil
+	return filepath.ToSlash(strings.TrimPrefix(srcDir, sourceRoot)), nil
 }

mockgen/parse_test.go

@@ -148,7 +148,7 @@ func TestParsePackageImport(t *testing.T) {
 			for key, value := range testCase.envs {
 				os.Setenv(key, value)
 			}
-			pkgPath, err := parsePackageImport(testCase.dir)
+			pkgPath, err := parsePackageImport(filepath.Clean(testCase.dir))
 			if err != testCase.err {
 				t.Errorf("expect %v, got %v", testCase.err, err)
 			}