Fixes #464 - Incorrect regex usage on extended grapheme clusters

ElementX/Sources/Other/Extensions/NSRegularExpresion.swift

@@ -0,0 +1,40 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+/// NSRegularExpressions work internally on NSStrings, we need to be careful how we build the ranges for extended grapheme clusters https://stackoverflow.com/a/27880748/730924
+extension NSRegularExpression {
+    func enumerateMatches(in string: String, options: NSRegularExpression.MatchingOptions = [], using block: (NSTextCheckingResult?, NSRegularExpression.MatchingFlags, UnsafeMutablePointer<ObjCBool>) -> Void) {
+        enumerateMatches(in: string, options: options, range: .init(location: 0, length: (string as NSString).length), using: block)
+    }
+    
+    func matches(in string: String, options: NSRegularExpression.MatchingOptions = []) -> [NSTextCheckingResult] {
+        matches(in: string, options: options, range: .init(location: 0, length: (string as NSString).length))
+    }
+    
+    func numberOfMatches(in string: String, options: NSRegularExpression.MatchingOptions = []) -> Int {
+        numberOfMatches(in: string, options: options, range: .init(location: 0, length: (string as NSString).length))
+    }
+    
+    func firstMatch(in string: String, options: NSRegularExpression.MatchingOptions = []) -> NSTextCheckingResult? {
+        firstMatch(in: string, options: options, range: .init(location: 0, length: (string as NSString).length))
+    }
+    
+    func rangeOfFirstMatch(in string: String, options: NSRegularExpression.MatchingOptions = []) -> NSRange {
+        rangeOfFirstMatch(in: string, options: options, range: .init(location: 0, length: (string as NSString).length))
+    }
+}