Merge pull request #1373 from wordpress-mobile/fix/ios17-crash

Use NSString.paragraphRange method due to iOS 17 crash

Author: twstokes

Aztec/Classes/Extensions/NSAttributedString+ParagraphRange.swift

@@ -22,14 +22,13 @@ extension NSAttributedString {
     ///
     func paragraphRanges(intersecting range: NSRange, includeParagraphSeparator: Bool = true) -> [NSRange] {
         var paragraphRanges = [NSRange]()
-        let swiftRange = string.range(fromUTF16NSRange: range)
-        let paragraphsRange = string.paragraphRange(for: swiftRange)
-        
-        string.enumerateSubstrings(in: paragraphsRange, options: .byParagraphs) { [unowned self] (substring, substringRange, enclosingRange, stop) in
+        let paragraphsRange = foundationString.paragraphRange(for: range)
+
+        foundationString.enumerateSubstrings(in: paragraphsRange, options: .byParagraphs) { (substring, substringRange, enclosingRange, stop) in
             let paragraphRange = includeParagraphSeparator ? enclosingRange : substringRange
-            paragraphRanges.append(self.string.utf16NSRange(from: paragraphRange))
+            paragraphRanges.append(paragraphRange)
         }
-        
+
         return paragraphRanges
     }
 
@@ -44,16 +43,12 @@ extension NSAttributedString {
     ///
     func paragraphRanges(intersecting range: NSRange) -> ([ParagraphRange]) {
         var paragraphRanges = [ParagraphRange]()
-        let swiftRange = string.range(fromUTF16NSRange: range)
-        let paragraphsRange = string.paragraphRange(for: swiftRange)
-        
-        string.enumerateSubstrings(in: paragraphsRange, options: .byParagraphs) { [unowned self] (substring, substringRange, enclosingRange, stop) in
-            let substringNSRange = self.string.utf16NSRange(from: substringRange)
-            let enclosingNSRange = self.string.utf16NSRange(from: enclosingRange)
-            
-            paragraphRanges.append((substringNSRange, enclosingNSRange))
+        let paragraphsRange = foundationString.paragraphRange(for: range)
+
+        foundationString.enumerateSubstrings(in: paragraphsRange, options: .byParagraphs) { (substring, substringRange, enclosingRange, stop) in
+            paragraphRanges.append((substringRange, enclosingRange))
         }
-        
+
         return paragraphRanges
     }
 
@@ -62,10 +57,7 @@ extension NSAttributedString {
     /// This is an attributed string wrapper for `NSString.paragraphRangeForRange()`
     ///
     func paragraphRange(for range: NSRange) -> NSRange {
-        let swiftRange = string.range(fromUTF16NSRange: range)
-        let outRange = string.paragraphRange(for: swiftRange)
-        
-        return string.utf16NSRange(from: outRange)
+        return foundationString.paragraphRange(for: range)
     }
 
     func paragraphRange(for attachment: NSTextAttachment) -> NSRange {

AztecTests/Extensions/NSAttributedStringParagraphRangeTests.swift

@@ -46,4 +46,54 @@ class NSAttributedStringParagraphRangeTests: XCTestCase {
         XCTAssertEqual(ranges.first?.rangeExcludingParagraphSeparator, expectedRangeWithoutSeparator)
         XCTAssertEqual(ranges.first?.rangeIncludingParagraphSeparator, expectedRangeWithSeparator)
     }
+
+    /// Tests that `paragraphRange(for:)` with a paragraph separator character
+    /// returns the correct `NSRange`.
+    ///
+    /// This test was added due to an iOS 17 crash when calling String.paragraphRange(for: range)
+    /// on a single paragraph separator character.
+    ///
+    func testParagraphRangeWorkWithParagraphSeparator() {
+        let attributedString = NSAttributedString(string: "\u{2029}")
+        let range = NSRange(location: 0, length: 1)
+        let expectedRange = NSRange(location: 0, length: 1)
+
+        let paragraphRange = attributedString.paragraphRange(for: range)
+
+        XCTAssertEqual(paragraphRange, expectedRange)
+    }
+
+    /// Tests that `paragraphRanges(intersecting:)` with a paragraph separator character
+    /// returns the correct `[NSRange]`.
+    ///
+    /// This test was added due to an iOS 17 crash when calling String.paragraphRange(for: range)
+    /// on a single paragraph separator character.
+    ///
+    func testParagraphRangesWorkWithParagraphSeparator() {
+        let attributedString = NSAttributedString(string: "\u{2029}")
+        let range = NSRange(location: 0, length: 1)
+        let expectedRange = NSRange(location: 0, length: 1)
+
+        let ranges = attributedString.paragraphRanges(intersecting: range, includeParagraphSeparator: true)
+
+        XCTAssertEqual(ranges.first!, expectedRange)
+    }
+
+    /// Tests that `paragraphRanges(intersecting:)` with a paragraph separator character
+    /// returns the correct `ParagraphRange`.
+    ///
+    /// This test was added due to an iOS 17 crash when calling String.paragraphRange(for: range)
+    /// on a single paragraph separator character.
+    ///
+    func testParagraphRangesWorkWithAndWithoutParagraphSeparator() {
+        let attributedString = NSAttributedString(string: "\u{2029}")
+        let range = NSRange(location: 0, length: 1)
+        let expectedRangeWithoutSeparator = NSRange(location: 0, length: 0)
+        let expectedRangeWithSeparator = NSRange(location: 0, length: 1)
+
+        let ranges = attributedString.paragraphRanges(intersecting: range)
+
+        XCTAssertEqual(ranges.first!.rangeIncludingParagraphSeparator, expectedRangeWithSeparator)
+        XCTAssertEqual(ranges.first!.rangeExcludingParagraphSeparator, expectedRangeWithoutSeparator)
+    }
 }

CHANGELOG.md

@@ -42,7 +42,7 @@ _None._
 
 ### Bug Fixes
 
-_None._
+* Worked around a crash that could occur when calling String.paragraphRange(for:) on iOS 17. [#1373]
 
 ### Internal Changes