Fix browser empty string flag parsing

chromium/browser_type.go

@@ -304,7 +304,7 @@ func parseArgs(flags map[string]any) ([]string, error) {
 	for name, value := range flags {
 		switch value := value.(type) {
 		case string:
-			args = append(args, fmt.Sprintf("--%s=%s", name, value))
+			args = append(args, parseStringArg(name, value))
 		case bool:
 			if value {
 				args = append(args, fmt.Sprintf("--%s", name))
@@ -324,6 +324,15 @@ func parseArgs(flags map[string]any) ([]string, error) {
 	return args, nil
 }
 
+func parseStringArg(flag string, value string) string {
+	if strings.TrimSpace(value) == "" {
+		// If the value is empty, we don't include it in the args list.
+		// Otherwise, it will produce "--name=" which is invalid.
+		return fmt.Sprintf("--%s", flag)
+	}
+	return fmt.Sprintf("--%s=%s", flag, value)
+}
+
 func prepareFlags(lopts *common.BrowserOptions, k6opts *k6lib.Options) (map[string]any, error) {
 	// After Puppeteer's and Playwright's default behavior.
 	f := map[string]any{

chromium/browser_type_test.go

@@ -4,6 +4,7 @@ import (
 	"io/fs"
 	"net"
 	"path/filepath"
+	"sort"
 	"testing"
 
 	"github.com/grafana/xk6-browser/common"
@@ -251,3 +252,86 @@ func TestExecutablePath(t *testing.T) {
 		})
 	}
 }
+
+func TestParseArgs(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name  string
+		flags map[string]any
+		want  []string
+	}{
+		{
+			name: "string_flag_with_value",
+			flags: map[string]any{
+				"flag1": "value1",
+				"flag2": "value2",
+			},
+			want: []string{
+				"--flag1=value1",
+				"--flag2=value2",
+				"--remote-debugging-port=0",
+			},
+		},
+		{
+			name: "string_flag_with_empty_value",
+			flags: map[string]any{
+				"flag1": "",
+				"flag2": "value2",
+			},
+			want: []string{
+				"--flag1",
+				"--flag2=value2",
+				"--remote-debugging-port=0",
+			},
+		},
+		{
+			name: "bool_flag_true",
+			flags: map[string]any{
+				"flag1": true,
+				"flag2": true,
+			},
+			want: []string{
+				"--flag1",
+				"--flag2",
+				"--remote-debugging-port=0",
+			},
+		},
+		{
+			name: "bool_flag_false",
+			flags: map[string]any{
+				"flag1": false,
+				"flag2": true,
+			},
+			want: []string{
+				"--flag2",
+				"--remote-debugging-port=0",
+			},
+		},
+		{
+			name: "invalid_flag_type",
+			flags: map[string]any{
+				"flag1": 123,
+			},
+			want: nil,
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			got, err := parseArgs(tt.flags)
+
+			if tt.want == nil {
+				assert.Error(t, err)
+				return
+			}
+			require.NoError(t, err)
+			sort.StringSlice(tt.want).Sort()
+			sort.StringSlice(got).Sort()
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}