add ShlexSplit() as an alternative to shlex.Split()

api/internal/plugins/execplugin/shlex.go

@@ -5,15 +5,55 @@ package execplugin
 
 import (
 	"fmt"
-
-	shlex "github.com/carapace-sh/carapace-shlex"
+	"strings"
+	"unicode"
 )
 
+// ShlexSplit splits a string into a slice of strings using shell-style rules for quoting and commenting
+// Similar to Python's shlex.split with comments enabled
 func ShlexSplit(s string) ([]string, error) {
-	// return shlexSplit(s)
-	tokens, err := shlex.Split(s)
-	if err != nil {
-		return nil, fmt.Errorf("shlex split error: %w", err)
-	}
-	return tokens.Strings(), nil
+	return shlexSplit(s)
+}
+
+func shlexSplit(s string) ([]string, error) {
+	result := []string{}
+
+	var current strings.Builder
+	var quote rune
+	var escaped bool
+
+	for _, r := range s {
+		switch {
+		case escaped:
+			current.WriteRune(r)
+			escaped = false
+		case r == '\\' && quote != '\'':
+			escaped = true
+		case (r == '\'' || r == '"') && quote == 0:
+			quote = r
+		case r == quote:
+			quote = 0
+		case r == '#' && quote == 0:
+			// Comment starts, ignore the rest of the line
+			if current.Len() > 0 {
+				result = append(result, current.String())
+			}
+			return result, nil
+		case quote == 0 && unicode.IsSpace(r):
+			if current.Len() > 0 {
+				result = append(result, current.String())
+				current.Reset()
+			}
+		default:
+			current.WriteRune(r)
+		}
+	}
+
+	if quote != 0 {
+		return nil, fmt.Errorf("unclosed quote in string")
+	}
+	if current.Len() > 0 {
+		result = append(result, current.String())
+	}
+	return result, nil
 }

api/internal/plugins/execplugin/shlex_test.go

@@ -103,13 +103,13 @@ func TestShlexSplit(t *testing.T) {
 		{
 			name:     "empty string",
 			input:    ``,
-			expected: []string{""},
+			expected: []string{},
 			wantErr:  false,
 		},
 		{
 			name:     "multiple spaces",
-			input:    `   multiple   spaces   `,
-			expected: []string{"multiple", "spaces", ""},
+			input:    `   multiple	spaces   `,
+			expected: []string{"multiple", "spaces"},
 			wantErr:  false,
 		},
 		{
@@ -118,36 +118,42 @@ func TestShlexSplit(t *testing.T) {
 			expected: []string{"echo", "Hello, W#orld!", "${USER}"},
 			wantErr:  false,
 		},
+		{
+			name:     "comment only",
+			input:    `# this line is just a comment`,
+			expected: []string{},
+			wantErr:  false,
+		},
 		// may cause an error in shlex at python3
 		{
 			name:     "unclosed double quote",
 			input:    `"unclosed quote`,
-			expected: []string{"unclosed quote"},
-			wantErr:  false,
+			expected: nil,
+			wantErr:  true,
 		},
 		{
 			name:     "unclosed single quote",
 			input:    `'unclosed quote`,
-			expected: []string{"unclosed quote"},
-			wantErr:  false,
+			expected: nil,
+			wantErr:  true,
 		},
 		{
 			name:     "mixed unclosed quotes",
 			input:    `"mixed 'quotes`,
-			expected: []string{"mixed 'quotes"},
-			wantErr:  false,
+			expected: nil,
+			wantErr:  true,
 		},
 		{
 			name:     "single quote closed with double quote",
 			input:    `"hello world'`,
-			expected: []string{"hello world'"},
-			wantErr:  false,
+			expected: nil,
+			wantErr:  true,
 		},
 		{
 			name:     "double quote closed with single quote",
 			input:    `'hello world"`,
-			expected: []string{"hello world\""},
-			wantErr:  false,
+			expected: nil,
+			wantErr:  true,
 		},
 	}
 
@@ -165,7 +171,7 @@ func TestShlexSplit(t *testing.T) {
 				return
 			}
 
-			if assert.NoError(t, err, "FAIL: Unexpected error for input %q", tc.input) {
+			if assert.NoError(t, err, "FAIL: Unexpected error %q for input %q", err, tc.input) {
 				// check if the result matches the expected output
 				assert.Equal(t, tc.expected, result,
 					"FAIL: Result mismatch,Input %q, Expected %q, Got: %q\n",