From da4e0c4073e4d0b6b4b95b63ed5c1ee0fbe629c5 Mon Sep 17 00:00:00 2001
From: Karl Stolley <karl@zulip.com>
Date: Thu, 3 Aug 2023 13:01:10 -0500
Subject: [PATCH] compose: Allow URLs to be pasted onto selected text.

Fixes: #18692
---
 package.json              |  1 +
 pnpm-lock.yaml            |  7 +++++++
 web/src/compose_ui.js     | 10 +++++++++-
 web/src/copy_and_paste.js | 21 ++++++++++++++++++++-
 4 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/package.json b/package.json
index 103ba0eadc..b56b4899d0 100644
--- a/package.json
+++ b/package.json
@@ -44,6 +44,7 @@
     "handlebars-loader": "^1.7.1",
     "html-webpack-plugin": "^5.3.2",
     "intl-messageformat": "^10.3.0",
+    "is-url": "^1.2.4",
     "jquery": "^3.6.3",
     "jquery-caret-plugin": "^1.5.2",
     "jquery-validation": "^1.19.0",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 03467ce0a9..438134d4e2 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -134,6 +134,9 @@ dependencies:
   intl-messageformat:
     specifier: ^10.3.0
     version: 10.5.0
+  is-url:
+    specifier: ^1.2.4
+    version: 1.2.4
   jquery:
     specifier: ^3.6.3
     version: 3.7.0
@@ -7455,6 +7458,10 @@ packages:
       unc-path-regex: 0.1.2
     dev: false
 
+  /is-url@1.2.4:
+    resolution: {integrity: sha512-ITvGim8FhRiYe4IQ5uHSkj7pVaPDrCTkNd3yq3cV7iZAcJdHTUMPMEHcqSOy9xZ9qFenQCvi+2wjH9a1nXqHww==}
+    dev: false
+
   /is-utf8@0.2.1:
     resolution: {integrity: sha512-rMYPYvCzsXywIsldgLaSoPlw5PfoB/ssr7hY4pLfcodrA5M/eArza1a9VmTiNIBNMjOGr1Ow9mTyU2o69U6U9Q==}
     dev: false
diff --git a/web/src/compose_ui.js b/web/src/compose_ui.js
index 8acc0d3630..151aab6685 100644
--- a/web/src/compose_ui.js
+++ b/web/src/compose_ui.js
@@ -343,7 +343,7 @@ export function handle_keyup(_event, $textarea) {
     rtl.set_rtl_class_for_textarea($textarea);
 }
 
-export function format_text($textarea, type) {
+export function format_text($textarea, type, inserted_content) {
     const italic_syntax = "*";
     const bold_syntax = "**";
     const bold_and_italic_syntax = "***";
@@ -507,6 +507,14 @@ export function format_text($textarea, type) {
             field.setSelectionRange(new_start, new_end);
             break;
         }
+        case "linked": {
+            // From a paste event with a URL as inserted content
+            wrapSelection(field, "[", `](${inserted_content})`);
+            // Put the cursor at the end of the selection range
+            // and all wrapped material
+            $textarea.caret(range.end + `[](${inserted_content})`.length);
+            break;
+        }
     }
 }
 
diff --git a/web/src/copy_and_paste.js b/web/src/copy_and_paste.js
index 11400708fb..6a7d7d6ca9 100644
--- a/web/src/copy_and_paste.js
+++ b/web/src/copy_and_paste.js
@@ -1,3 +1,4 @@
+import isUrl from "is-url";
 import $ from "jquery";
 import TurndownService from "turndown";
 
@@ -341,7 +342,25 @@ export function paste_handler(event) {
     }
 
     if (clipboardData.getData) {
+        const $textarea = $(event.currentTarget);
+        const paste_text = clipboardData.getData("text");
         const paste_html = clipboardData.getData("text/html");
+        // Trim the paste_text to accommodate sloppy copying
+        const trimmed_paste_text = paste_text.trim();
+        const range = $textarea.range();
+
+        // Only try to generate formatted links when dealing with a URL
+        // and a range selection. Note that even clipboards with "text/html"
+        // have a "text" equivalent, so we need an if statement that checks
+        // for more than a value on `trimmed_paste_text`
+        if (isUrl(trimmed_paste_text) && range.text) {
+            event.preventDefault();
+            event.stopPropagation();
+            const url = trimmed_paste_text;
+            compose_ui.format_text($textarea, "linked", url);
+            return;
+        }
+
         if (paste_html && page_params.development_environment) {
             const text = paste_handler_converter(paste_html);
             const mdImageRegex = /^!\[.*]\(.*\)$/;
@@ -359,5 +378,5 @@ export function paste_handler(event) {
 
 export function initialize() {
     $("#compose-textarea").on("paste", paste_handler);
-    $("body").on("paste", ".message_edit_form", paste_handler);
+    $("body").on("paste", ".message_edit_content", paste_handler);
 }