nushell: use lexer to patch arguments

complete.go

@@ -2,6 +2,7 @@ package carapace
 
 import (
 	"github.com/rsteube/carapace/internal/config"
+	"github.com/rsteube/carapace/internal/shell/nushell"
 	"github.com/rsteube/carapace/pkg/ps"
 	"github.com/spf13/cobra"
 )
@@ -14,6 +15,10 @@ func complete(cmd *cobra.Command, args []string) (string, error) {
 		return Gen(cmd).Snippet(args[0])
 	default:
 		initHelpCompletion(cmd)
+
+		if shell := ps.DetermineShell(); shell == "nushell" {
+			args = nushell.Patch(args)
+		}
 		action, context := traverse(cmd, args[2:])
 		if err := config.Load(); err != nil {
 			action = ActionMessage("failed to load config: " + err.Error())

internal/shell/nushell/action.go

@@ -18,6 +18,11 @@ var sanitizer = strings.NewReplacer(
 	"\r", ``,
 )
 
+var escaper = strings.NewReplacer(
+	`\`, `\\`,
+	`"`, `\"`,
+)
+
 func sanitize(values []common.RawValue) []common.RawValue {
 	for index, v := range values {
 		(&values[index]).Value = sanitizer.Replace(v.Value)
@@ -32,7 +37,12 @@ func ActionRawValues(currentWord string, meta common.Meta, values common.RawValu
 	vals := make([]record, len(values))
 	for index, val := range sanitize(values) {
 		if strings.ContainsAny(val.Value, ` {}()[]<>$&"|;#\`+"`") {
-			val.Value = fmt.Sprintf("'%v'", val.Value)
+			switch {
+			case strings.HasPrefix(val.Value, "~"):
+				val.Value = fmt.Sprintf(`~"%v"`, escaper.Replace(val.Value[1:]))
+			default:
+				val.Value = fmt.Sprintf(`"%v"`, escaper.Replace(val.Value))
+			}
 		}
 
 		if !meta.Nospace.Matches(val.Value) {

internal/shell/nushell/patch.go

@@ -0,0 +1,29 @@
+package nushell
+
+import (
+	"strings"
+
+	"github.com/rsteube/carapace/internal/lexer"
+)
+
+// Patch uses the lexer to parse and patch given arguments which
+// are currently passed unprocessed to the completion function.
+//
+// see https://www.nushell.sh/book/working_with_strings.html
+func Patch(args []string) []string {
+	for index, arg := range args {
+		if len(arg) == 0 {
+			continue
+		}
+
+		switch arg[0] {
+		case '"', "'"[0]:
+			if tokenset, err := lexer.Split(arg, false); err == nil {
+				args[index] = tokenset.Tokens[0]
+			}
+		case '`':
+			args[index] = strings.Trim(arg, "`")
+		}
+	}
+	return args
+}