Fix couldn't load package bug, if multiple GOPATH exists and target code is not in first GOPATH

parser/parser_test.go

@@ -0,0 +1,52 @@
+// Copyright 2017 Google Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to writing, software distributed
+// under the License is distributed on a "AS IS" BASIS, WITHOUT WARRANTIES OR
+// CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package parser
+
+import (
+	"go/build"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func must(t *testing.T, err error) {
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+var fakeCode = `
+package main
+import "fmt"
+func main() {
+	fmt.Println("Hello world!")
+}
+`
+
+func TestParseFromMultipleGopath(t *testing.T) {
+	gopaths := filepath.SplitList(build.Default.GOPATH)
+	if len(gopaths) < 2 {
+		t.Skipf("No multiple GOPATH (%s) exists, skiping..", build.Default.GOPATH)
+	}
+	gopath := gopaths[len(gopaths)-1]
+	dir := filepath.Join(gopath, "src", "foo")
+	defer must(t, os.RemoveAll(dir))
+	must(t, os.MkdirAll(dir, 0755))
+	must(t, ioutil.WriteFile(filepath.Join(dir, "main.go"), []byte(fakeCode), 0644))
+
+	if _, err := ParsePackage(dir); err != nil {
+		t.Fatalf("Parse package (%v): %v", dir, err)
+	}
+}