added possibility to escape formatting characters

see #562

src/api/api.go

@@ -395,7 +395,7 @@ func (a *Api) Send(c *gin.Context) {
 
 // @Summary Send a signal message.
 // @Tags Messages
-// @Description Send a signal message. Set the text_mode to 'styled' in case you want to add formatting to your text message. Styling Options: *italic text*, **bold text**, ~strikethrough text~.
+// @Description Send a signal message. Set the text_mode to 'styled' in case you want to add formatting to your text message. Styling Options: *italic text*, **bold text**, ~strikethrough text~. If you want to escape a character, prefix it with two backslashes ('\\')
 // @Accept  json
 // @Produce  json
 // @Success 201 {object} SendMessageResponse

src/docs/docs.go

@@ -2014,7 +2014,7 @@ const docTemplate = `{
         },
         "/v2/send": {
             "post": {
-                "description": "Send a signal message. Set the text_mode to 'styled' in case you want to add formatting to your text message. Styling Options: *italic text*, **bold text**, ~strikethrough text~.",
+                "description": "Send a signal message. Set the text_mode to 'styled' in case you want to add formatting to your text message. Styling Options: *italic text*, **bold text**, ~strikethrough text~. If you want to escape a character, prefix it with two backslashes ('\\\\')",
                 "consumes": [
                     "application/json"
                 ],

src/docs/swagger.json

@@ -2011,7 +2011,7 @@
         },
         "/v2/send": {
             "post": {
-                "description": "Send a signal message. Set the text_mode to 'styled' in case you want to add formatting to your text message. Styling Options: *italic text*, **bold text**, ~strikethrough text~.",
+                "description": "Send a signal message. Set the text_mode to 'styled' in case you want to add formatting to your text message. Styling Options: *italic text*, **bold text**, ~strikethrough text~. If you want to escape a character, prefix it with two backslashes ('\\\\')",
                 "consumes": [
                     "application/json"
                 ],

src/docs/swagger.yaml

@@ -1754,7 +1754,8 @@ paths:
       - application/json
       description: 'Send a signal message. Set the text_mode to ''styled'' in case
         you want to add formatting to your text message. Styling Options: *italic
-        text*, **bold text**, ~strikethrough text~.'
+        text*, **bold text**, ~strikethrough text~. If you want to escape a character,
+        prefix it with two backslashes (''\\'')'
       parameters:
       - description: Input Data
         in: body

src/utils/textstyleparser.go

@@ -25,6 +25,8 @@ const (
 	SpoilerBegin           = 9
 )
 
+const EscapeCharacter rune = '\\'
+
 func getUtf16StringLength(s string) int {
 	runes := []rune(s) //turn string to slice
 
@@ -74,7 +76,6 @@ type TextstyleParser struct {
 	tokens                 Stack
 	fullString             string
 	signalCliFormatStrings []string
-	//numOfControlTokens int
 }
 
 func NewTextstyleParser(input string) *TextstyleParser {
@@ -93,9 +94,6 @@ func (l *TextstyleParser) next() (rune rune) {
 		l.width = 0
 		return eof
 	}
-	//r := []rune(l.input[l.pos:])[0]
-	//l.width = utf16.RuneLen(r)
-	//l.pos += l.width
 	rune, l.width = utf8.DecodeRuneInString(l.input[l.pos:])
 	l.pos += l.width
 	return rune
@@ -129,6 +127,7 @@ func (l *TextstyleParser) handleToken(tokenType int, signalCliStylingType string
 }
 
 func (l *TextstyleParser) Parse() (string, []string) {
+	var prevChar rune
 	for {
 		c := l.next()
 		if c == eof {
@@ -140,20 +139,45 @@ func (l *TextstyleParser) Parse() (string, []string) {
 		if c == '*' {
 			if nextRune == '*' { //Bold
 				l.next()
+				if prevChar == EscapeCharacter {
+					prevChar = c
+					continue
+				}
 				l.handleToken(BoldBegin, Bold)
 			} else { //Italic
+				if prevChar == EscapeCharacter {
+					prevChar = c
+					continue
+				}
 				l.handleToken(ItalicBegin, Italic)
 			}
 		} else if (c == '|') && (nextRune == '|') {
 			l.next()
+			if prevChar == EscapeCharacter {
+				prevChar = c
+				continue
+			}
 			l.handleToken(SpoilerBegin, Spoiler)
 		} else if c == '~' {
+			if prevChar == EscapeCharacter {
+				prevChar = c
+				continue
+			}
 			l.handleToken(StrikethroughBegin, Strikethrough)
 		} else if c == '`' {
+			if prevChar == EscapeCharacter {
+				prevChar = c
+				continue
+			}
 			l.handleToken(MonoSpaceBegin, Monospace)
+		} else if ((c == EscapeCharacter) && (nextRune == '*')) || ((c == EscapeCharacter) && (nextRune == '`')) || ((c == EscapeCharacter) && (nextRune == '|')) || ((c == EscapeCharacter) && (nextRune == '~')) {
+			prevChar = c
+			continue
 		} else {
 			l.fullString += string(c)
 		}
+
+		prevChar = c
 	}
 
 	return l.fullString, l.signalCliFormatStrings

src/utils/textstyleparser_test.go

@@ -119,3 +119,31 @@ func TestBoldTextInsideSpoiler(t *testing.T) {
 	expectMessageEqual(t, message, "this is a bold text inside a spoiler")
 	expectFormatStringsEqual(t, signalCliFormatStrings, []string{"0:36:BOLD", "0:36:SPOILER"})
 }
+
+func TestEscapeAsterisks(t *testing.T) {
+	textstyleParser := NewTextstyleParser("\\*escaped text\\*")
+	message, signalCliFormatStrings := textstyleParser.Parse()
+	expectMessageEqual(t, message, "escaped text")
+	expectFormatStringsEqual(t, signalCliFormatStrings, []string{})
+}
+
+func TestEscapeAsterisks1(t *testing.T) {
+	textstyleParser := NewTextstyleParser("\\**escaped text\\**")
+	message, signalCliFormatStrings := textstyleParser.Parse()
+	expectMessageEqual(t, message, "escaped text")
+	expectFormatStringsEqual(t, signalCliFormatStrings, []string{})
+}
+
+func TestEscapeBackticks(t *testing.T) {
+	textstyleParser := NewTextstyleParser("\\`escaped text\\`")
+	message, signalCliFormatStrings := textstyleParser.Parse()
+	expectMessageEqual(t, message, "escaped text")
+	expectFormatStringsEqual(t, signalCliFormatStrings, []string{})
+}
+
+func TestEscapeTilde(t *testing.T) {
+	textstyleParser := NewTextstyleParser("\\~escaped text\\~")
+	message, signalCliFormatStrings := textstyleParser.Parse()
+	expectMessageEqual(t, message, "escaped text")
+	expectFormatStringsEqual(t, signalCliFormatStrings, []string{})
+}