From fc9bb7cec159f92b77af45d352378c50c952856d Mon Sep 17 00:00:00 2001
From: Katsute <58778985+Katsute@users.noreply.github.com>
Date: Sat, 9 Sep 2023 05:00:25 -0400
Subject: [PATCH] Skip truncated links (#40)

Co-authored-by: Federico Brigante <me@fregante.com>
---
 index.js | 16 +++++++++++++---
 test.js  | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/index.js b/index.js
index af4e5fe..98702cc 100644
--- a/index.js
+++ b/index.js
@@ -19,12 +19,22 @@ const linkify = (href, options) => createHtmlElement({
 // Get DOM node from HTML
 const domify = html => document.createRange().createContextualFragment(html);
 
-const getAsString = (string, options) => string.replace(urlRegex(), match => linkify(match, options));
+const isTruncated = (url, peek) =>
+	url.endsWith('...') // `...` is a matched by the URL regex
+	|| peek.startsWith('…'); // `…` can follow the match
+
+const getAsString = (string, options) => string.replace(urlRegex(), (url, _, offset) =>
+	(isTruncated(url, string.charAt(offset + url.length)))
+		? url // Don't linkify truncated URLs
+		: linkify(url, options));
 
 const getAsDocumentFragment = (string, options) => {
 	const fragment = document.createDocumentFragment();
-	for (const [index, text] of Object.entries(string.split(urlRegex()))) {
-		if (index % 2) { // URLs are always in odd positions
+	const parts = string.split(urlRegex());
+
+	for (const [index, text] of parts.entries()) {
+		// URLs are always in odd positions
+		if (index % 2 && !isTruncated(text, parts[index + 1])) {
 			fragment.append(domify(linkify(text, options)));
 		} else if (text.length > 0) {
 			fragment.append(text);
diff --git a/test.js b/test.js
index 50ceee4..93ef67c 100644
--- a/test.js
+++ b/test.js
@@ -147,3 +147,41 @@ test('supports localhost URLs', t => {
 	t.is(linkifyUrls('https://localhost'), '<a href="https://localhost">https://localhost</a>');
 	t.is(linkifyUrls('https://localhost/foo/bar'), '<a href="https://localhost/foo/bar">https://localhost/foo/bar</a>');
 });
+
+test('skips truncated URLs', t => {
+	t.is(linkifyUrls('https://github.com/sindresorhus/linkify-…'), 'https://github.com/sindresorhus/linkify-…');
+	t.is(linkifyUrls('https://github.com/sindresorhus/linkify-… and https://github.com/sindresorhus/linkify-…'), 'https://github.com/sindresorhus/linkify-… and https://github.com/sindresorhus/linkify-…');
+	t.is(linkifyUrls('https://github.com/sindresorhus/linkify-urls and more…'), '<a href="https://github.com/sindresorhus/linkify-urls">https://github.com/sindresorhus/linkify-urls</a> and more…');
+
+	t.is(linkifyUrls('https://github.com/sindresorhus/linkify-...'), 'https://github.com/sindresorhus/linkify-...');
+	t.is(linkifyUrls('https://github.com/sindresorhus/linkify-... and https://github.com/sindresorhus/linkify-...'), 'https://github.com/sindresorhus/linkify-... and https://github.com/sindresorhus/linkify-...');
+	t.is(linkifyUrls('https://github.com/sindresorhus/linkify-urls and more...'), '<a href="https://github.com/sindresorhus/linkify-urls">https://github.com/sindresorhus/linkify-urls</a> and more...');
+});
+
+test('skips truncated URLs (DocumentFragment)', t => {
+	t.is(
+		html(linkifyUrls('See https://github.com/sindresorhus/linkify-urls and https://github.com/sindresorhus/linkify-…', {
+			type: 'dom',
+		})),
+		html(domify('See <a href="https://github.com/sindresorhus/linkify-urls">https://github.com/sindresorhus/linkify-urls</a> and https://github.com/sindresorhus/linkify-…')),
+	);
+	t.is(
+		html(linkifyUrls('See https://github.com/sindresorhus/linkify-urls… and https://github.com/sindresorhus/linkify-…', {
+			type: 'dom',
+		})),
+		html(domify('See https://github.com/sindresorhus/linkify-urls… and https://github.com/sindresorhus/linkify-…')),
+	);
+
+	t.is(
+		html(linkifyUrls('See https://github.com/sindresorhus/linkify-urls and https://github.com/sindresorhus/linkify-...', {
+			type: 'dom',
+		})),
+		html(domify('See <a href="https://github.com/sindresorhus/linkify-urls">https://github.com/sindresorhus/linkify-urls</a> and https://github.com/sindresorhus/linkify-...')),
+	);
+	t.is(
+		html(linkifyUrls('See https://github.com/sindresorhus/linkify-... and https://github.com/sindresorhus/linkify-...', {
+			type: 'dom',
+		})),
+		html(domify('See https://github.com/sindresorhus/linkify-... and https://github.com/sindresorhus/linkify-...')),
+	);
+});