feat(markdownv2): add general markdownv2 support

only implements the existing interface right now

readme.md

@@ -20,10 +20,12 @@ $ npm install telegram-format
 ## Usage
 
 ```js
-const {markdown: format} = require('telegram-format');
 const {html: format} = require('telegram-format');
-import {markdown as format} from 'telegram-format';
+const {markdown: format} = require('telegram-format');
+const {markdownv2: format} = require('telegram-format');
 import {html as format} from 'telegram-format';
+import {markdown as format} from 'telegram-format';
+import {markdownv2 as format} from 'telegram-format';
 
 format.bold('hey');
 //=> '*hey*'

source/index.ts

@@ -1,3 +1,5 @@
 export * from './interface'
+
 export * from './html'
 export * from './markdown'
+export * from './markdownv2'

source/interface.ts

@@ -1,5 +1,5 @@
 export interface Formatter {
-	parse_mode: 'HTML' | 'Markdown';
+	parse_mode: 'HTML' | 'Markdown' | 'MarkdownV2';
 	bold: (text: string) => string;
 	escape: (text: string) => string;
 	italic: (text: string) => string;

source/markdownv2.ts

@@ -0,0 +1,57 @@
+// https://core.telegram.org/bots/api#markdownv2-style
+
+import {Formatter} from './interface'
+
+function escapeInteral(text: string, escapeChars: string): string {
+	return text.replace(new RegExp(`[${escapeChars}\\\\]`, 'g'), '\\$&')
+}
+
+function escape(text: string): string {
+	return text.replace(/[_*[\]()~`>#+-=|{}.!]/g, '\\$&')
+}
+
+function bold(text: string): string {
+	return `*${escape(text)}*`
+}
+
+function italic(text: string): string {
+	return `_${escape(text)}_`
+}
+
+function monospace(text: string): string {
+	return '`' + escapeInteral(text, '`') + '`'
+}
+
+function monospaceBlock(text: string, programmingLanguage?: string): string {
+	let result = ''
+	result += '```'
+
+	if (programmingLanguage) {
+		result += programmingLanguage
+	}
+
+	result += '\n'
+	result += escapeInteral(text, '`')
+	result += '\n'
+	result += '```'
+	return result
+}
+
+function url(label: string, url: string): string {
+	return `[${escapeInteral(label, '\\]')}](${escapeInteral(url, ')')})`
+}
+
+function userMention(label: string, userId: number): string {
+	return url(label, `tg://user?id=${userId}`)
+}
+
+export const markdownv2: Formatter = {
+	parse_mode: 'MarkdownV2',
+	escape,
+	bold,
+	italic,
+	monospace,
+	monospaceBlock,
+	url,
+	userMention
+}

test/markdownv2.ts

@@ -0,0 +1,43 @@
+import test from 'ava'
+
+import {markdownv2 as format} from '../source'
+
+test('bold', t => {
+	t.is(format.bold('bold'), '*bold*')
+})
+
+test('italic', t => {
+	t.is(format.italic('italic'), '_italic_')
+})
+
+test('url', t => {
+	t.is(format.url('me', 'https://edjopato.de'), '[me](https://edjopato.de)')
+})
+
+test('escape', t => {
+	t.is(format.escape('[h_]e(*y)`'), '\\[h\\_\\]e\\(\\*y\\)\\`')
+})
+
+test('bold malicious', t => {
+	t.is(format.bold('bo*ld'), '*bo\\*ld*')
+})
+
+test('italic malicious', t => {
+	t.is(format.italic('ita_lic'), '_ita\\_lic_')
+})
+
+test('user mention', t => {
+	t.is(format.userMention('inline mention of a user', 123456789), '[inline mention of a user](tg://user?id=123456789)')
+})
+
+test('monospace', t => {
+	t.is(format.monospace('inline fixed-width code'), '`inline fixed-width code`')
+})
+
+test('monospaceBlock w/o language', t => {
+	t.is(format.monospaceBlock('pre-formatted fixed-width code block'), '```\npre-formatted fixed-width code block\n```')
+})
+
+test('monospaceBlock w/ language', t => {
+	t.is(format.monospaceBlock('pre-formatted fixed-width code block written in the Python programming language', 'python'), '```python\npre-formatted fixed-width code block written in the Python programming language\n```')
+})