(new): tgfmt package

(fix): formatting helpers
(ci/cd): go checks
(tests): tgfmt coverage

tgfmt/mdv2.go

@@ -0,0 +1,103 @@
+package tgfmt
+
+import (
+	"strconv"
+	"strings"
+)
+
+// MarkdownV2 is an escaped Telegram MarkdownV2 fragment.
+//
+// Methods on MarkdownV2 compose formatting without escaping the fragment again.
+type MarkdownV2 string
+
+// EscapeMarkdownV2 escapes special characters for Telegram MarkdownV2.
+// https://core.telegram.org/bots/api#markdownv2-style
+func EscapeMarkdownV2(s string) MarkdownV2 {
+	symbols := []string{"\\", "_", "*", "[", "]", "(", ")", "~", "`", ">", "#", "+", "-", "=", "|", "{", "}", ".", "!"}
+	for _, symbol := range symbols {
+		s = strings.ReplaceAll(s, symbol, "\\"+symbol)
+	}
+	return MarkdownV2(s)
+}
+
+// Bold returns s wrapped as bold Telegram MarkdownV2 text.
+func (s MarkdownV2) Bold() MarkdownV2 {
+	return "*" + s + "*"
+}
+
+// Italic returns s wrapped as italic Telegram MarkdownV2 text.
+func (s MarkdownV2) Italic() MarkdownV2 {
+	return "_" + s + "_"
+}
+
+// Underline returns s wrapped as underlined Telegram MarkdownV2 text.
+func (s MarkdownV2) Underline() MarkdownV2 {
+	return "__" + s + "__"
+}
+
+// Strikethrough returns s wrapped as strikethrough Telegram MarkdownV2 text.
+func (s MarkdownV2) Strikethrough() MarkdownV2 {
+	return "~" + s + "~"
+}
+
+// Spoiler returns s wrapped as spoiler Telegram MarkdownV2 text.
+func (s MarkdownV2) Spoiler() MarkdownV2 {
+	return "||" + s + "||"
+}
+
+// Link returns s as a Telegram MarkdownV2 text link.
+func (s MarkdownV2) Link(url string) MarkdownV2 {
+	return "[" + s + "](" + escapeMarkdownV2LinkDestination(url) + ")"
+}
+
+// Mention returns s as a Telegram MarkdownV2 user mention.
+func (s MarkdownV2) Mention(userID uint64) MarkdownV2 {
+	return "[" + s + "](tg://user?id=" + MarkdownV2(strconv.FormatUint(userID, 10)) + ")"
+}
+
+// Emoji returns s as a Telegram MarkdownV2 custom emoji.
+func (s MarkdownV2) Emoji(emojiID string) MarkdownV2 {
+	return "[" + s + "](tg://emoji?id=" + escapeMarkdownV2LinkDestination(emojiID) + ")"
+}
+
+// Time returns s as a Telegram MarkdownV2 localized timestamp.
+func (s MarkdownV2) Time(unix uint64) MarkdownV2 {
+	return "![" + s + "](tg://time?unix=" + MarkdownV2(strconv.FormatUint(unix, 10)) + ")"
+}
+
+// TimeFormat returns s as a Telegram MarkdownV2 localized timestamp with format.
+func (s MarkdownV2) TimeFormat(unix uint64, format string) MarkdownV2 {
+	dest := "tg://time?unix=" + strconv.FormatUint(unix, 10) + "&format=" + format
+	return "![" + s + "](" + escapeMarkdownV2LinkDestination(dest) + ")"
+}
+
+// InlineCode returns s wrapped as inline code Telegram MarkdownV2 text.
+func (s MarkdownV2) InlineCode() MarkdownV2 {
+	return "`" + s + "`"
+}
+
+// BlockCode returns s wrapped as a Telegram MarkdownV2 code block.
+func (s MarkdownV2) BlockCode() MarkdownV2 {
+	return "```\n" + s + "\n```"
+}
+
+// BlockCodeLanguage returns s wrapped as a Telegram MarkdownV2 code block with language.
+func (s MarkdownV2) BlockCodeLanguage(lang string) MarkdownV2 {
+	return "```" + MarkdownV2(lang) + "\n" + s + "\n```"
+}
+
+// Quote returns s as a Telegram MarkdownV2 blockquote.
+func (s MarkdownV2) Quote() MarkdownV2 {
+	return MarkdownV2(">" + strings.ReplaceAll(string(s), "\n", "\n>"))
+}
+
+// QuoteExpandable returns s as a Telegram MarkdownV2 expandable blockquote.
+func (s MarkdownV2) QuoteExpandable() MarkdownV2 {
+	return "**>" + s
+}
+
+func escapeMarkdownV2LinkDestination(s string) MarkdownV2 {
+	s = strings.ReplaceAll(s, "\\", "\\\\")
+	s = strings.ReplaceAll(s, ")", "\\)")
+	return MarkdownV2(s)
+}