From 4d07e9cf5bbf246e3aa4e71e28bf5cac52747f26 Mon Sep 17 00:00:00 2001
From: gabriellsh <40830821+gabriellsh@users.noreply.github.com>
Date: Mon, 26 Apr 2021 11:16:20 -0300
Subject: [PATCH] regression: Markdown broken on safari (#21780)

Co-authored-by: Guilherme Gazzo <guilhermegazzo@gmail.com>
---
 app/markdown/lib/parser/original/markdown.js | 23 +++++++++--
 app/markdown/tests/client.tests.js           | 41 +++++++++++++++-----
 2 files changed, 50 insertions(+), 14 deletions(-)

diff --git a/app/markdown/lib/parser/original/markdown.js b/app/markdown/lib/parser/original/markdown.js
index 3ddfc04c52b..eec53e6e11c 100644
--- a/app/markdown/lib/parser/original/markdown.js
+++ b/app/markdown/lib/parser/original/markdown.js
@@ -33,6 +33,21 @@ const validateUrl = (url, message) => {
 	}
 };
 
+const getParserWithCustomMarker = (marker, tagName) => (msg) => msg.replace(new RegExp(`(\\${ marker }+(?!\\s))([^\\${ marker }\r\n]+)(\\${ marker }+)`, 'gm'), (match, p1, p2, p3) => {
+	if (p2.substring(p2.length - 1).match(/\s/)) {
+		return match;
+	}
+	const usableMarkers = p1.length > 1 ? 2 : 1;
+	const finalMarkerCount = p3.length - usableMarkers >= 0 ? usableMarkers : 1;
+	return `${ p1.substring(finalMarkerCount) }<span class="copyonly">${ marker }</span><${ tagName }>${ p2 }</${ tagName }><span class="copyonly">${ marker }</span>${ p3.substring(finalMarkerCount) }`;
+});
+
+const parseBold = getParserWithCustomMarker('*', 'strong');
+
+const parseItalic = getParserWithCustomMarker('_', 'em');
+
+const parseStrike = getParserWithCustomMarker('~', 'strike');
+
 const parseNotEscaped = (message, {
 	supportSchemesForLink,
 	headers,
@@ -60,13 +75,13 @@ const parseNotEscaped = (message, {
 	}
 
 	// Support *text* to make bold
-	msg = msg.replace(/\*{1,2}(?!\s)([^\*\r\n]+)(?<!\s)\*{1,2}/gm, '<span class="copyonly">*</span><strong>$1</strong><span class="copyonly">*</span>');
+	msg = parseBold(msg);
 
 	// Support _text_ to make italics
-	msg = msg.replace(/(?<!\_)\_{1,2}(?!\s)([^\_\r\n]+)(?<!\s)\_{1,2}(?!\_)/gm, '<span class="copyonly">_</span><em>$1</em><span class="copyonly">_</span>');
+	msg = parseItalic(msg);
 
-	// Support ~text~ to strike through text
-	msg = msg.replace(/(?<!\~)\~{1,2}(?!\s)([^~\r\n]+)(?<!\s)\~{1,2}(?!\~)/gm, '<span class="copyonly">~</span><strike>$1</strike><span class="copyonly">~</span>');
+	// // Support ~text~ to strike through text
+	msg = parseStrike(msg);
 
 	// Support for block quote
 	// >>>
diff --git a/app/markdown/tests/client.tests.js b/app/markdown/tests/client.tests.js
index fd92206771d..d6f3c3728cf 100644
--- a/app/markdown/tests/client.tests.js
+++ b/app/markdown/tests/client.tests.js
@@ -19,10 +19,17 @@ const inlinecodeWrapper = (text) => wrapper(`<span><code class="code-colors inli
 const codeWrapper = (text, lang) => `<pre><code class='code-colors hljs ${ lang }'><span class='copyonly'>\`\`\`<br></span>${ text }<span class='copyonly'><br>\`\`\`</span></code></pre>`;
 
 const bold = {
+	'**': '**',
+	'* *': '* *',
+	'** *': '** *',
+	'** **': '** **',
+	'* Hello*': '* Hello*',
+	'*Hello *': '*Hello *',
+	'*Hel lo*': boldWrapper('Hel lo'),
 	'*Hello*': boldWrapper('Hello'),
 	'**Hello**': boldWrapper('Hello'),
-	'**Hello*': boldWrapper('Hello'),
-	'*Hello**': boldWrapper('Hello'),
+	'**Hello*': `*${ boldWrapper('Hello') }`,
+	'*Hello**': `${ boldWrapper('Hello') }*`,
 	Hello: 'Hello',
 	'*Hello': '*Hello',
 	'Hello*': 'Hello*',
@@ -40,16 +47,23 @@ const bold = {
 };
 
 const italic = {
+	__: '__',
+	'_ _': '_ _',
+	'__ _': '__ _',
+	'__ __': '__ __',
+	'_ Hello_': '_ Hello_',
+	'_Hello _': '_Hello _',
+	'_Hel lo_': italicWrapper('Hel lo'),
 	_Hello_: italicWrapper('Hello'),
 	__Hello__: italicWrapper('Hello'),
-	__Hello_: italicWrapper('Hello'),
-	_Hello__: italicWrapper('Hello'),
+	__Hello_: `_${ italicWrapper('Hello') }`,
+	_Hello__: `${ italicWrapper('Hello') }_`,
 	Hello: 'Hello',
 	_Hello: '_Hello',
 	Hello_: 'Hello_',
 	He_llo: 'He_llo',
-	___Hello___: '___Hello___',
-	___Hello__: '___Hello__',
+	___Hello___: `_${ italicWrapper('Hello') }_`,
+	___Hello__: `_${ italicWrapper('Hello') }`,
 	'_Hello_ this is dog': `${ italicWrapper('Hello') } this is dog`,
 	'Rocket cat says _Hello_': `Rocket cat says ${ italicWrapper('Hello') }`,
 	'He said _Hello_ to her': `He said ${ italicWrapper('Hello') } to her`,
@@ -59,16 +73,23 @@ const italic = {
 };
 
 const strike = {
+	'~~': '~~',
+	'~ ~': '~ ~',
+	'~~ ~': '~~ ~',
+	'~~ ~~': '~~ ~~',
+	'~ Hello~': '~ Hello~',
+	'~Hello ~': '~Hello ~',
+	'~Hel lo~': strikeWrapper('Hel lo'),
 	'~Hello~': strikeWrapper('Hello'),
 	'~~Hello~~': strikeWrapper('Hello'),
-	'~~Hello~': strikeWrapper('Hello'),
-	'~Hello~~': strikeWrapper('Hello'),
+	'~~Hello~': `~${ strikeWrapper('Hello') }`,
+	'~Hello~~': `${ strikeWrapper('Hello') }~`,
 	Hello: 'Hello',
 	'~Hello': '~Hello',
 	'Hello~': 'Hello~',
 	'He~llo': 'He~llo',
-	'~~~Hello~~~': '~~~Hello~~~',
-	'~~~Hello~~': '~~~Hello~~',
+	'~~~Hello~~~': `~${ strikeWrapper('Hello') }~`,
+	'~~~Hello~~': `~${ strikeWrapper('Hello') }`,
 	'~Hello~ this is dog': `${ strikeWrapper('Hello') } this is dog`,
 	'Rocket cat says ~Hello~': `Rocket cat says ${ strikeWrapper('Hello') }`,
 	'He said ~Hello~ to her': `He said ${ strikeWrapper('Hello') } to her`,