path: Dir

There was Base but not Dir, so fill in the gap.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5504076

diff --git a/src/pkg/path/path.go b/src/pkg/path/path.go
index 235384667c678c2c1630368ee30640cd630926c8..20d89c9ff0cbcbee125e1c88ffa198cc67563ef5 100644 (file)
--- a/src/pkg/path/path.go
+++ b/src/pkg/path/path.go
@@ -160,3 +160,21 @@ func Base(path string) string {
 func IsAbs(path string) bool {
        return len(path) > 0 && path[0] == '/'
 }
+
+// Dir returns the all but the last element of path, typically the path's directory.
+// Trailing path separators are removed before processing.
+// If the path is empty, Dir returns ".".
+// If the path consists entirely of separators, Dir returns a single separator.
+// The returned path does not end in a separator unless it is the root directory.
+func Dir(path string) string {
+       dir, _ := Split(path)
+       dir = Clean(dir)
+       last := len(dir) - 1
+       if last > 0 && dir[last] == '/' {
+               dir = dir[:last]
+       }
+       if dir == "" {
+               dir = "."
+       }
+       return dir
+}

diff --git a/src/pkg/path/path_test.go b/src/pkg/path/path_test.go
index 1fd57cc800ec7eccff173f03239463f2bfc81c0c..77f080433b667719f103ec09f9f57656b4d4c907 100644 (file)
--- a/src/pkg/path/path_test.go
+++ b/src/pkg/path/path_test.go
@@ -8,11 +8,11 @@ import (
        "testing"
 )
 
-type CleanTest struct {
-       path, clean string
+type PathTest struct {
+       path, result string
 }
 
-var cleantests = []CleanTest{
+var cleantests = []PathTest{
        // Already clean
        {"", "."},
        {"abc", "abc"},
@@ -64,8 +64,8 @@ var cleantests = []CleanTest{
 
 func TestClean(t *testing.T) {
        for _, test := range cleantests {
-               if s := Clean(test.path); s != test.clean {
-                       t.Errorf("Clean(%q) = %q, want %q", test.path, s, test.clean)
+               if s := Clean(test.path); s != test.result {
+                       t.Errorf("Clean(%q) = %q, want %q", test.path, s, test.result)
                }
        }
 }
@@ -148,7 +148,7 @@ func TestExt(t *testing.T) {
        }
 }
 
-var basetests = []CleanTest{
+var basetests = []PathTest{
        // Already clean
        {"", "."},
        {".", "."},
@@ -165,8 +165,31 @@ var basetests = []CleanTest{
 
 func TestBase(t *testing.T) {
        for _, test := range basetests {
-               if s := Base(test.path); s != test.clean {
-                       t.Errorf("Base(%q) = %q, want %q", test.path, s, test.clean)
+               if s := Base(test.path); s != test.result {
+                       t.Errorf("Base(%q) = %q, want %q", test.path, s, test.result)
+               }
+       }
+}
+
+var dirtests = []PathTest{
+       {"", "."},
+       {".", "."},
+       {"/.", "/"},
+       {"/", "/"},
+       {"////", "/"},
+       {"/foo", "/"},
+       {"x/", "x"},
+       {"abc", "."},
+       {"abc/def", "abc"},
+       {"a/b/.x", "a/b"},
+       {"a/b/c.", "a/b"},
+       {"a/b/c.x", "a/b"},
+}
+
+func TestDir(t *testing.T) {
+       for _, test := range dirtests {
+               if s := Dir(test.path); s != test.result {
+                       t.Errorf("Dir(%q) = %q, want %q", test.path, s, test.result)
                }
        }
 }