fix: address verified review findings (terminal-forms-1)

Signed-off-by: bircni <bircni@icloud.com>

internal/terminal/form_fields.go

@@ -3,7 +3,14 @@
 
 package terminal
 
-import "charm.land/huh/v2"
+import (
+	"errors"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"charm.land/huh/v2"
+)
 
 // BodyTitle labels the markdown body of issues, pull requests and comments.
 const BodyTitle = "Body (markdown):"
@@ -11,9 +18,17 @@ const BodyTitle = "Body (markdown):"
 // maxVisibleOptions bounds how many options a multi-select shows before it scrolls.
 const maxVisibleOptions = 8
 
+// notBlank rejects empty and whitespace-only answers, which huh.ValidateNotEmpty accepts.
+func notBlank(s string) error {
+	if strings.TrimSpace(s) == "" {
+		return errors.New("input cannot be empty")
+	}
+	return nil
+}
+
 // titleField is the required one-line title of an issue, pull request or similar resource.
 func titleField(value *string) *huh.Input {
-	return huh.NewInput().Title("Title (required):").Value(value).Validate(huh.ValidateNotEmpty())
+	return huh.NewInput().Title("Title (required):").Value(value).Validate(notBlank)
 }
 
 // bodyField is an inline multi-line markdown field. It has no external editor: forms run the
@@ -22,6 +37,26 @@ func bodyField(title string, value *string) *huh.Text {
 	return huh.NewText().Title(title).Value(value).ExternalEditor(false)
 }
 
+// fieldText is how a multi-line field shows seed: its textarea turns every CR and LF into a line
+// break and a tab into four spaces, and drops other control characters.
+func fieldText(seed string) string {
+	return strings.Map(func(r rune) rune {
+		if r == utf8.RuneError || (unicode.IsControl(r) && r != '\n') {
+			return -1
+		}
+		return r
+	}, strings.NewReplacer("\r", "\n", "\t", "    ").Replace(seed))
+}
+
+// fieldResult is the answer of a multi-line field seeded with seed: seed itself when the user
+// changed nothing, so a plain Enter does not rewrite existing text such as CRLF line endings.
+func fieldResult(seed, answer string) string {
+	if answer == fieldText(seed) {
+		return seed
+	}
+	return answer
+}
+
 // multiSelect lists every option, scrolling past maxVisibleOptions. Without an explicit height,
 // huh sizes the list to its options minus the title line and hides the last option.
 func multiSelect[T comparable](title string, options []huh.Option[T], value *[]T) *huh.MultiSelect[T] {