lib/bucket: add IsAllSlashes function

lib/bucket/bucket.go

@@ -42,6 +42,21 @@ func Join(path1, path2 string) string {
 	return strings.TrimSuffix(path1, "/") + "/" + strings.TrimPrefix(path2, "/")
 }
 
+// IsAllSlashes returns true if s is all / characters.
+//
+// It returns false if s is "".
+func IsAllSlashes(s string) bool {
+	if len(s) == 0 {
+		return false
+	}
+	for _, c := range s {
+		if c != '/' {
+			return false
+		}
+	}
+	return true
+}
+
 // Cache stores whether buckets are available and their IDs
 type Cache struct {
 	mu       sync.Mutex      // mutex to protect created and deleted

lib/bucket/bucket_test.go

@@ -45,6 +45,24 @@ func TestJoin(t *testing.T) {
 	}
 }
 
+func TestIsAllSlashes(t *testing.T) {
+	for _, test := range []struct {
+		in   string
+		want bool
+	}{
+		{in: "", want: false},
+		{in: "/", want: true},
+		{in: "x/", want: false},
+		{in: "/x", want: false},
+		{in: "//", want: true},
+		{in: "/x/", want: false},
+		{in: "///", want: true},
+	} {
+		got := IsAllSlashes(test.in)
+		assert.Equal(t, test.want, got, test.in)
+	}
+}
+
 func TestCache(t *testing.T) {
 	c := NewCache()
 	errBoom := errors.New("boom")