gps: add unwrapVcsErr nil cause test

Author: jmank88

internal/gps/source_errors_test.go

@@ -0,0 +1,30 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gps
+
+import (
+	"testing"
+
+	"github.com/Masterminds/vcs"
+)
+
+func TestUnwrapVcsErrNonNil(t *testing.T) {
+	for _, err := range []error{
+		vcs.NewRemoteError("msg", nil, "out"),
+		vcs.NewRemoteError("msg", nil, ""),
+		vcs.NewRemoteError("", nil, "out"),
+		vcs.NewRemoteError("", nil, ""),
+		vcs.NewLocalError("msg", nil, "out"),
+		vcs.NewLocalError("msg", nil, ""),
+		vcs.NewLocalError("", nil, "out"),
+		vcs.NewLocalError("", nil, ""),
+		&vcs.RemoteError{},
+		&vcs.LocalError{},
+	} {
+		if unwrapVcsErr(err) == nil {
+			t.Errorf("unexpected nil error unwrapping: %#v", err)
+		}
+	}
+}