From 0804f3359d8246437e010087693408df723f9deb Mon Sep 17 00:00:00 2001
From: kean <grebenyuk.alexander@gmail.com>
Date: Mon, 4 Apr 2022 20:02:47 -0400
Subject: [PATCH] Fix indexes when working with characters containing multiple
 unicode scalars

---
 Source/Formatting.swift     | 3 +++
 Tests/FormattingTests.swift | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/Source/Formatting.swift b/Source/Formatting.swift
index 5708a02..e9534a7 100644
--- a/Source/Formatting.swift
+++ b/Source/Formatting.swift
@@ -118,6 +118,9 @@ private final class Parser: NSObject, XMLParserDelegate {
         let output = NSMutableAttributedString(string: text)
         // Apply tags in reverse, more specific tags are applied last.
         for (range, attributes) in attributes.reversed() {
+            let lb = text.index(text.startIndex, offsetBy: range.lowerBound)
+            let ub = text.index(text.startIndex, offsetBy: range.upperBound)
+            let range = NSRange(lb..<ub, in: text)
             output.addAttributes(attributes, range: range)
         }
         return output
diff --git a/Tests/FormattingTests.swift b/Tests/FormattingTests.swift
index a257095..140ff82 100644
--- a/Tests/FormattingTests.swift
+++ b/Tests/FormattingTests.swift
@@ -198,7 +198,8 @@ class FormattingsTests: XCTestCase {
         ])
 
         // WHEN
-        let input = "⚠ Text with <t>emoji</t>"
+        // important: ⚠️ contains two unicode scalars
+        let input = "⚠️ Text with <t>emoji</t>"
         let output = NSAttributedString(formatting: input, style: style)
 
         //  THEN