Add Map version `ProcessWords`

Signed-off-by: Yuichiro Kaneko <spiketeika@gmail.com>

frontend/dockerfile/shell/lex.go

@@ -51,6 +51,11 @@ func (s *Lex) ProcessWordWithMap(word string, env map[string]string) (string, er
 	return word, err
 }
 
+func (s *Lex) ProcessWordsWithMap(word string, env map[string]string) ([]string, error) {
+	_, words, err := s.process(word, env)
+	return words, err
+}
+
 func (s *Lex) process(word string, env map[string]string) (string, []string, error) {
 	sw := &shellWord{
 		envs:        env,

frontend/dockerfile/shell/lex_test.go

@@ -103,6 +103,7 @@ func TestShellParser4Words(t *testing.T) {
 		test := strings.TrimSpace(words[0])
 		expected := strings.Split(strings.TrimLeft(words[1], " "), ",")
 
+		// test for ProcessWords
 		result, err := shlex.ProcessWords(test, envs)
 
 		if err != nil {
@@ -117,6 +118,22 @@ func TestShellParser4Words(t *testing.T) {
 				t.Fatalf("Error on line %d. %q was suppose to result in %q, but got %q instead", lineNum, test, expected, result)
 			}
 		}
+
+		// test for ProcessWordsWithMap
+		result, err = shlex.ProcessWordsWithMap(test, buildEnvs(envs))
+
+		if err != nil {
+			result = []string{"error"}
+		}
+
+		if len(result) != len(expected) {
+			t.Fatalf("Error on line %d. %q was suppose to result in %q, but got %q instead", lineNum, test, expected, result)
+		}
+		for i, w := range expected {
+			if w != result[i] {
+				t.Fatalf("Error on line %d. %q was suppose to result in %q, but got %q instead", lineNum, test, expected, result)
+			}
+		}
 	}
 }