fix: don't append ... for fields with an explicit type

Fixes #346

kong_test.go

@@ -2460,3 +2460,18 @@ func TestApplyCalledOnce(t *testing.T) {
 	err = kctx.Run()
 	assert.NoError(t, err)
 }
+
+func TestCustomTypeNoEllipsis(t *testing.T) {
+	type CLI struct {
+		Flag []byte `type:"existingfile"`
+	}
+	var cli CLI
+	p := mustNew(t, &cli, kong.Exit(func(int) {}))
+	w := &strings.Builder{}
+	p.Stderr = w
+	p.Stdout = w
+	_, err := p.Parse([]string{"--help"})
+	assert.NoError(t, err)
+	help := w.String()
+	assert.NotContains(t, help, "...")
+}

model.go

@@ -433,7 +433,7 @@ func (f *Flag) FormatPlaceHolder() string {
 		return placeholderHelper.PlaceHolder(f)
 	}
 	tail := ""
-	if f.Value.IsSlice() && f.Value.Tag.Sep != -1 {
+	if f.Value.IsSlice() && f.Value.Tag.Sep != -1 && f.Tag.Type == "" {
 		tail += string(f.Value.Tag.Sep) + "..."
 	}
 	if f.PlaceHolder != "" {
@@ -446,7 +446,7 @@ func (f *Flag) FormatPlaceHolder() string {
 		return f.Default + tail
 	}
 	if f.Value.IsMap() {
-		if f.Value.Tag.MapSep != -1 {
+		if f.Value.Tag.MapSep != -1 && f.Tag.Type == "" {
 			tail = string(f.Value.Tag.MapSep) + "..."
 		}
 		return "KEY=VALUE" + tail