go/buildutil, cmd/guru: fix tests for symlinks in guru and gorename to account for windows

Restructure tests to account for possibility of being run on Windows
(which doesn't handle symlinks).

Change-Id: I428db26c9a1aad337d8972baa2b71468be3a2e58
Reviewed-on: https://go-review.googlesource.com/33920
Reviewed-by: Alan Donovan <adonovan@google.com>

cmd/guru/unit_test.go

@@ -9,6 +9,7 @@ import (
 	"go/build"
 	"io/ioutil"
 	"os"
+	"runtime"
 	"strings"
 	"testing"
 )
@@ -35,25 +36,34 @@ func TestIssue17515(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// symlink between /tmp/home/go/src and /tmp/home/src
-	if err = os.Symlink(home+"/go/src", home+"/src"); err != nil {
-		t.Fatal(err)
-	}
-
-	// Defer tear down (removing files, symlinks)
 	defer os.RemoveAll(home)
 
 	var buildContext = build.Default
 
 	// Success test cases
-	for _, test := range []struct {
+	type SuccessTest struct {
 		gopath, filename, wantSrcdir string
-	}{
+	}
+
+	successTests := []SuccessTest{
 		{home + "/go", home + "/go/src/test/test.go", home + "/go/src"},
+	}
+
+	// Add symlink cases if not on windows
+	if runtime.GOOS != "windows" {
+		// symlink between /tmp/home/go/src and /tmp/home/src
+		if err := os.Symlink(home+"/go/src", home+"/src"); err != nil {
+			t.Fatal(err)
+		}
+
+		successTests = append(successTests, []SuccessTest{
 			{home + "/go", home + "/src/test/test.go", home + "/go/src"},
-		{home, home + "/src/test/test.go", home + "/src"},
 			{home, home + "/go/src/test/test.go", home + "/src"},
-	} {
+			{home, home + "/src/test/test.go", home + "/src"},
+		}...)
+	}
+
+	for _, test := range successTests {
 		buildContext.GOPATH = test.gopath
 		srcdir, importPath, err := guessImportPath(test.filename, &buildContext)
 		if srcdir != test.wantSrcdir || importPath != "test" || err != nil {
@@ -67,14 +77,23 @@ func TestIssue17515(t *testing.T) {
 	}
 
 	// Failure test cases
-	for _, test := range []struct {
+	type FailTest struct {
 		gopath, filename, wantErr string
-	}{
+	}
+
+	failTests := []FailTest{
 		{home + "/go", home + "/go/src/fake/test.go", errFormat(home + "/go/src/fake")},
+	}
+
+	if runtime.GOOS != "windows" {
+		failTests = append(failTests, []FailTest{
 			{home + "/go", home + "/src/fake/test.go", errFormat(home + "/src/fake")},
 			{home, home + "/src/fake/test.go", errFormat(home + "/src/fake")},
 			{home, home + "/go/src/fake/test.go", errFormat(home + "/go/src/fake")},
-	} {
+		}...)
+	}
+
+	for _, test := range failTests {
 		buildContext.GOPATH = test.gopath
 		srcdir, importPath, err := guessImportPath(test.filename, &buildContext)
 		if !strings.HasPrefix(fmt.Sprint(err), test.wantErr) {

go/buildutil/util.go

@@ -68,7 +68,7 @@ func ContainingPackage(ctxt *build.Context, dir, filename string) (*build.Packag
 
 	resolvedFilename, err := filepath.EvalSymlinks(filepath.Dir(filename))
 	if err != nil {
-		return nil, fmt.Errorf("can't evaluate symlinks of %s: %v", path.Dir(filename), err)
+		return nil, fmt.Errorf("can't evaluate symlinks of %s: %v", filepath.Dir(filename), err)
 	}
 
 	resolvedDir := filepath.ToSlash(resolvedFilename)

go/buildutil/util_test.go

@@ -24,35 +24,40 @@ func TestContainingPackage(t *testing.T) {
 	goroot := runtime.GOROOT()
 	gopath := filepath.SplitList(os.Getenv("GOPATH"))[0]
 
+	type Test struct {
+		gopath, filename, wantPkg string
+	}
+
+	tests := []Test{
+		{gopath, goroot + "/src/fmt/print.go", "fmt"},
+		{gopath, goroot + "/src/encoding/json/foo.go", "encoding/json"},
+		{gopath, goroot + "/src/encoding/missing/foo.go", "(not found)"},
+		{gopath, gopath + "/src/golang.org/x/tools/go/buildutil/util_test.go",
+			"golang.org/x/tools/go/buildutil"},
+	}
+
+	if runtime.GOOS != "windows" {
 		// Make a symlink to gopath for test
 		tmp, err := ioutil.TempDir(os.TempDir(), "go")
 		if err != nil {
 			t.Errorf("Unable to create a temporary directory in %s", os.TempDir())
 		}
 
+		defer os.RemoveAll(tmp)
+
 		// symlink between $GOPATH/src and /tmp/go/src
 		// in order to test all possible symlink cases
 		if err := os.Symlink(gopath+"/src", tmp+"/src"); err != nil {
 			t.Fatal(err)
 		}
+		tests = append(tests, []Test{
+			{gopath, tmp + "/src/golang.org/x/tools/go/buildutil/util_test.go", "golang.org/x/tools/go/buildutil"},
+			{tmp, gopath + "/src/golang.org/x/tools/go/buildutil/util_test.go", "golang.org/x/tools/go/buildutil"},
+			{tmp, tmp + "/src/golang.org/x/tools/go/buildutil/util_test.go", "golang.org/x/tools/go/buildutil"},
+		}...)
+	}
 
-	defer os.RemoveAll(tmp)
+	for _, test := range tests {
-
-	for _, test := range []struct {
-		gopath, filename, wantPkg string
-	}{
-		{gopath, goroot + "/src/fmt/print.go", "fmt"},
-		{gopath, goroot + "/src/encoding/json/foo.go", "encoding/json"},
-		{gopath, goroot + "/src/encoding/missing/foo.go", "(not found)"},
-		{gopath, gopath + "/src/golang.org/x/tools/go/buildutil/util_test.go",
-			"golang.org/x/tools/go/buildutil"},
-		{gopath, tmp + "/src/golang.org/x/tools/go/buildutil/util_test.go",
-			"golang.org/x/tools/go/buildutil"},
-		{tmp, gopath + "/src/golang.org/x/tools/go/buildutil/util_test.go",
-			"golang.org/x/tools/go/buildutil"},
-		{tmp, tmp + "/src/golang.org/x/tools/go/buildutil/util_test.go",
-			"golang.org/x/tools/go/buildutil"},
-	} {
 		var got string
 		var buildContext = build.Default
 		buildContext.GOPATH = test.gopath