Refactor SplitShellStrings

internal/backend/sftp/sftp.go

@@ -179,7 +179,12 @@ func (r *SFTP) IsNotExist(err error) bool {
 
 func buildSSHCommand(cfg Config) (cmd string, args []string, err error) {
 	if cfg.Command != "" {
-		return backend.SplitShellArgs(cfg.Command)
+		args, err := backend.SplitShellStrings(cfg.Command)
+		if err != nil {
+			return "", nil, err
+		}
+
+		return args[0], args[1:], nil
 	}
 
 	cmd = "ssh"

internal/backend/shell_split.go

@@ -41,8 +41,8 @@ func (s *shellSplitter) isSplitChar(c rune) bool {
 	return c == '\\' || unicode.IsSpace(c)
 }
 
-// SplitShellArgs returns the list of arguments from a shell command string.
+// SplitShellStrings returns the list of shell strings from a shell command string.
-func SplitShellArgs(data string) (cmd string, args []string, err error) {
+func SplitShellStrings(data string) (strs []string, err error) {
 	s := &shellSplitter{}
 
 	// derived from strings.SplitFunc
@@ -50,7 +50,7 @@ func SplitShellArgs(data string) (cmd string, args []string, err error) {
 	for i, rune := range data {
 		if s.isSplitChar(rune) {
 			if fieldStart >= 0 {
-				args = append(args, data[fieldStart:i])
+				strs = append(strs, data[fieldStart:i])
 				fieldStart = -1
 			}
 		} else if fieldStart == -1 {
@@ -58,21 +58,19 @@ func SplitShellArgs(data string) (cmd string, args []string, err error) {
 		}
 	}
 	if fieldStart >= 0 { // Last field might end at EOF.
-		args = append(args, data[fieldStart:])
+		strs = append(strs, data[fieldStart:])
 	}
 
 	switch s.quote {
 	case '\'':
-		return "", nil, errors.New("single-quoted string not terminated")
+		return nil, errors.New("single-quoted string not terminated")
 	case '"':
-		return "", nil, errors.New("double-quoted string not terminated")
+		return nil, errors.New("double-quoted string not terminated")
 	}
 
-	if len(args) == 0 {
+	if len(strs) == 0 {
-		return "", nil, errors.New("command string is empty")
+		return nil, errors.New("command string is empty")
 	}
 
-	cmd, args = args[0], args[1:]
+	return strs, nil
-
-	return cmd, args, nil
 }

internal/backend/shell_split_test.go

@@ -8,59 +8,53 @@ import (
 func TestShellSplitter(t *testing.T) {
 	var tests = []struct {
 		data string
-		cmd  string
 		args []string
 	}{
 		{
 			`foo`,
-			"foo", []string{},
+			[]string{"foo"},
 		},
 		{
 			`'foo'`,
-			"foo", []string{},
+			[]string{"foo"},
 		},
 		{
 			`foo bar baz`,
-			"foo", []string{"bar", "baz"},
+			[]string{"foo", "bar", "baz"},
 		},
 		{
 			`foo 'bar' baz`,
-			"foo", []string{"bar", "baz"},
+			[]string{"foo", "bar", "baz"},
 		},
 		{
 			`'bar box' baz`,
-			"bar box", []string{"baz"},
+			[]string{"bar box", "baz"},
 		},
 		{
 			`"bar 'box'" baz`,
-			"bar 'box'", []string{"baz"},
+			[]string{"bar 'box'", "baz"},
 		},
 		{
 			`'bar "box"' baz`,
-			`bar "box"`, []string{"baz"},
+			[]string{`bar "box"`, "baz"},
 		},
 		{
 			`\"bar box baz`,
-			`"bar`, []string{"box", "baz"},
+			[]string{`"bar`, "box", "baz"},
 		},
 		{
 			`"bar/foo/x" "box baz"`,
-			"bar/foo/x", []string{"box baz"},
+			[]string{"bar/foo/x", "box baz"},
 		},
 	}
 
 	for _, test := range tests {
 		t.Run("", func(t *testing.T) {
-			cmd, args, err := SplitShellArgs(test.data)
+			args, err := SplitShellStrings(test.data)
 			if err != nil {
 				t.Fatal(err)
 			}
 
-			if cmd != test.cmd {
-				t.Fatalf("wrong cmd returned, want:\n  %#v\ngot:\n  %#v",
-					test.cmd, cmd)
-			}
-
 			if !reflect.DeepEqual(args, test.args) {
 				t.Fatalf("wrong args returned, want:\n  %#v\ngot:\n  %#v",
 					test.args, args)
@@ -94,7 +88,7 @@ func TestShellSplitterInvalid(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run("", func(t *testing.T) {
-			cmd, args, err := SplitShellArgs(test.data)
+			args, err := SplitShellStrings(test.data)
 			if err == nil {
 				t.Fatalf("expected error not found: %v", test.err)
 			}
@@ -103,10 +97,6 @@ func TestShellSplitterInvalid(t *testing.T) {
 				t.Fatalf("expected error not found, want:\n  %q\ngot:\n  %q", test.err, err.Error())
 			}
 
-			if cmd != "" {
-				t.Fatalf("splitter returned cmd from invalid data: %v", cmd)
-			}
-
 			if len(args) > 0 {
 				t.Fatalf("splitter returned fields from invalid data: %v", args)
 			}