Fix traling new lines appearing in attributed string when sending text separated by 2 new lines.

ElementX/Sources/Other/HTMLParsing/AttributedStringBuilderV2.swift

@@ -76,6 +76,7 @@ struct AttributedStringBuilderV2: AttributedStringBuilderProtocol {
         detectPhishingAttempts(mutableAttributedString)
         addLinksAndMentions(mutableAttributedString)
         addMatrixEntityPermalinkAttributesTo(mutableAttributedString)
+        removeParsingArtefacts(mutableAttributedString)
         
         let result = try? AttributedString(mutableAttributedString, including: \.elementX)
         Self.cacheValue(result, forKey: originalHTMLString, cacheKey: cacheKey)
@@ -410,6 +411,18 @@ struct AttributedStringBuilderV2: AttributedStringBuilderProtocol {
         
         attributedString.addAttribute(.link, value: finalURL, range: range)
     }
+    
+    private func removeParsingArtefacts(_ attributedString: NSMutableAttributedString) {
+        guard attributedString.length > 0 else {
+            return
+        }
+        
+        // Ruma's markdown parsing sometimes inserts extra trailing new lines
+        // https://github.com/ruma/ruma/blob/c3dc6de3e03b2ca131eab889a9d310ef160b95ac/crates/ruma-events/src/room/message.rs#L962
+        while (attributedString.string as NSString).hasSuffixCharacter(from: .whitespacesAndNewlines) {
+            attributedString.deleteCharacters(in: .init(location: attributedString.length - 1, length: 1))
+        }
+    }
 }
 
 private struct TextParsingMatch {

PreviewTests/Sources/__Snapshots__/PreviewTests/formattedBodyText.v2-iPad-en-GB.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:34fb889080b10018db0941940782f5c46ccf0611bb6bbf8cd2cefa8c0492f2a0
+oid sha256:bbe5650088750690bb31a4aaedbbee8e087222f86bf563fd3cb57e1a82f31e5e
-size 1110617
+size 1106686

PreviewTests/Sources/__Snapshots__/PreviewTests/formattedBodyText.v2-iPad-pseudo.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:34fb889080b10018db0941940782f5c46ccf0611bb6bbf8cd2cefa8c0492f2a0
+oid sha256:bbe5650088750690bb31a4aaedbbee8e087222f86bf563fd3cb57e1a82f31e5e
-size 1110617
+size 1106686

PreviewTests/Sources/__Snapshots__/PreviewTests/formattedBodyText.v2-iPhone-16-en-GB.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:60a1a287bd3c02dad38031e4ccfeafac7fc734384034147fa9b421090321eb05
+oid sha256:52ad9c6b5db4c5e876ef28aa019a3a75395c00d606daf56b961a43f10c6ae378
-size 1282490
+size 1281081

PreviewTests/Sources/__Snapshots__/PreviewTests/formattedBodyText.v2-iPhone-16-pseudo.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:60a1a287bd3c02dad38031e4ccfeafac7fc734384034147fa9b421090321eb05
+oid sha256:52ad9c6b5db4c5e876ef28aa019a3a75395c00d606daf56b961a43f10c6ae378
-size 1282490
+size 1281081

UnitTests/Sources/AttributedStringBuilderTests.swift

@@ -35,7 +35,7 @@ class AttributedStringBuilderV1Tests: XCTestCase {
         }
         
         if AttributedStringBuilder.useNextGenHTMLParser {
-            XCTAssertEqual(String(attributedString.characters), "H1 Header\n\nH2 Header\n\nH3 Header\n\nH4 Header\n\nH5 Header\n\nH6 Header\n")
+            XCTAssertEqual(String(attributedString.characters), "H1 Header\n\nH2 Header\n\nH3 Header\n\nH4 Header\n\nH5 Header\n\nH6 Header")
             
             XCTAssertEqual(attributedString.runs.count, 11) // newlines hold no attributes
 
@@ -172,32 +172,21 @@ class AttributedStringBuilderV1Tests: XCTestCase {
             return
         }
         
+        XCTAssertEqual(String(h1AttributedString.characters), "Matrix.org")
+        XCTAssertEqual(String(h2AttributedString.characters), "Matrix.org")
+        XCTAssertEqual(String(h3AttributedString.characters), "Matrix.org")
+        
+        XCTAssertEqual(h1AttributedString.runs.count, 1)
+        XCTAssertEqual(h2AttributedString.runs.count, 1)
+        XCTAssertEqual(h3AttributedString.runs.count, 1)
+        
+        XCTAssertEqual(h1Font, h2Font)
+        XCTAssertEqual(h2Font, h3Font)
+        
         if AttributedStringBuilder.useNextGenHTMLParser {
-            XCTAssertEqual(String(h1AttributedString.characters), "Matrix.org\n")
-            XCTAssertEqual(String(h2AttributedString.characters), "Matrix.org\n")
-            XCTAssertEqual(String(h3AttributedString.characters), "Matrix.org\n")
-            
-            XCTAssertEqual(h1AttributedString.runs.count, 2)
-            XCTAssertEqual(h2AttributedString.runs.count, 2)
-            XCTAssertEqual(h3AttributedString.runs.count, 2)
-            
-            XCTAssertEqual(h1Font, h2Font)
-            XCTAssertEqual(h2Font, h3Font)
-            
             XCTAssert(h1Font.pointSize > UIFont.preferredFont(forTextStyle: .body).pointSize)
             XCTAssert(h1Font.pointSize <= 23)
         } else {
-            XCTAssertEqual(String(h1AttributedString.characters), "Matrix.org")
-            XCTAssertEqual(String(h2AttributedString.characters), "Matrix.org")
-            XCTAssertEqual(String(h3AttributedString.characters), "Matrix.org")
-            
-            XCTAssertEqual(h1AttributedString.runs.count, 1)
-            XCTAssertEqual(h2AttributedString.runs.count, 1)
-            XCTAssertEqual(h3AttributedString.runs.count, 1)
-            
-            XCTAssertEqual(h1Font, h2Font)
-            XCTAssertEqual(h2Font, h3Font)
-            
             XCTAssert(h1Font.pointSize > UIFont.preferredFont(forTextStyle: .body).pointSize)
             XCTAssert(h1Font.pointSize <= maxHeaderPointSize)
         }
@@ -267,11 +256,9 @@ class AttributedStringBuilderV1Tests: XCTestCase {
             return
         }
         
-        if AttributedStringBuilder.useNextGenHTMLParser {
+        XCTAssertEqual(attributedString.runs.count, 3)
-            XCTAssertEqual(attributedString.runs.count, 4)
-        } else {
-            XCTAssertEqual(attributedString.runs.count, 3)
         
+        if !AttributedStringBuilder.useNextGenHTMLParser {
             for run in attributedString.runs {
                 XCTAssertEqual(run.uiKit.font?.familyName, UIFont.preferredFont(forTextStyle: .body).familyName)
             }