Handle relative import paths. (#102)

* Handle relative import paths.

* Rename relative-imports test data.

go/tools/gazelle/generator/generator_test.go

@@ -55,6 +55,13 @@ func TestGenerator(t *testing.T) {
 					},
 				},
 			},
+			"lib/relativeimporter": {
+				{
+					Call: &bzl.CallExpr{
+						X: &bzl.LiteralExpr{Token: "go_library"},
+					},
+				},
+			},
 			"bin": {
 				{
 					Call: &bzl.CallExpr{
@@ -108,6 +115,13 @@ func TestGenerator(t *testing.T) {
 				stub.fixtures["lib/internal/deep"][1].Call,
 			},
 		},
+		{
+			Path: "lib/relativeimporter/BUILD",
+			Stmt: []bzl.Expr{
+				loadExpr("go_library"),
+				stub.fixtures["lib/relativeimporter"][0].Call,
+			},
+		},
 		{
 			Path: "bin/BUILD",
 			Stmt: []bzl.Expr{

go/tools/gazelle/rules/generator.go

@@ -64,7 +64,7 @@ func NewGenerator(goPrefix string) Generator {
 	return &generator{
 		goPrefix: goPrefix,
 		r: resolverFunc(func(importpath, dir string) (label, error) {
-			if importpath != goPrefix && !strings.HasPrefix(importpath, goPrefix+"/") && !strings.HasPrefix(importpath, "./") {
+			if importpath != goPrefix && !strings.HasPrefix(importpath, goPrefix+"/") && !isRelative(importpath) {
 				return e.resolve(importpath, dir)
 			}
 			return r.resolve(importpath, dir)
@@ -202,3 +202,8 @@ func isStandard(importpath string) bool {
 	seg := strings.SplitN(importpath, "/", 2)[0]
 	return !strings.Contains(seg, ".")
 }
+
+// isRelative determines if an importpath is relative.
+func isRelative(importpath string) bool {
+	return strings.HasPrefix(importpath, "./") || strings.HasPrefix(importpath, "..")
+}

go/tools/gazelle/rules/generator_test.go

@@ -93,6 +93,17 @@ func TestGenerator(t *testing.T) {
 				)
 			`,
 		},
+		{
+			dir: "lib/relativeimporter",
+			want: `
+				go_library(
+					name = "go_default_library",
+					srcs = ["importer.go"],
+					visibility = ["//visibility:public"],
+					deps = ["//lib/internal/deep:go_default_library"],
+				)
+			`,
+		},
 		{
 			dir: "bin",
 			want: `

go/tools/gazelle/rules/resolve_structured.go

@@ -30,8 +30,8 @@ type structuredResolver struct {
 // resolve takes a Go importpath within the same respository as r.goPrefix
 // and resolves it into a label in Bazel.
 func (r structuredResolver) resolve(importpath, dir string) (label, error) {
-	if strings.HasPrefix(importpath, "./") {
-		importpath = path.Join(r.goPrefix, dir, importpath[2:])
+	if isRelative(importpath) {
+		importpath = path.Clean(path.Join(r.goPrefix, dir, importpath))
 	}
 
 	if importpath == r.goPrefix {

go/tools/gazelle/testdata/repo/lib/relativeimporter/importer.go

@@ -0,0 +1,24 @@
+/* Copyright 2016 The Bazel Authors. 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 in writing, software
+distributed under the License is distributed on an "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 relativeimporter
+
+import (
+	"log"
+
+	"../internal/deep"
+)
+
+func think() {
+	t := &deep.Thought{}
+	log.Println(t.Compute())
+}