feat: Mark syntax blocks

CDMarkdownKitTests/TestSyntax.swift

@@ -179,6 +179,28 @@ final class TestSyntax: XCTestCase {
         XCTAssertFalse(TestHelpers.isMonospaced(testString: parsed, at: 8))
     }
 
+    func testSyntaxBlockAttribute() throws {
+        let parser = getParser()
+
+        let parsed = parser.parse("a ```syntax``` c")
+        XCTAssertEqual(parsed.string, "a syntax c")
+
+        var effectiveRange = NSRange()
+        XCTAssertNotNil(parsed.attribute(.syntaxBlock, at: 3, effectiveRange: &effectiveRange))
+        XCTAssertEqual(effectiveRange, NSRange(location: 2, length: 6))
+
+        XCTAssertNil(parsed.attribute(.syntaxBlock, at: 0, effectiveRange: nil))
+        XCTAssertNil(parsed.attribute(.syntaxBlock, at: 9, effectiveRange: nil))
+    }
+
+    func testInlineCodeHasNoSyntaxBlockAttribute() throws {
+        let parser = getParser()
+
+        let parsed = parser.parse("a `code` c")
+        XCTAssertEqual(parsed.string, "a code c")
+        XCTAssertNil(parsed.attribute(.syntaxBlock, at: 3, effectiveRange: nil))
+    }
+
     func testEmojiInsideSyntax() throws {
         let parser = getParser()
 

Source/CDMarkdownSyntax.swift

@@ -80,6 +80,12 @@ open class CDMarkdownSyntax: CDMarkdownCommonElement {
         // Since we use NSRange here, we need to count based on UTF16, alternatively could use NSString length property
         let range = NSRange(location: range.location,
                             length: unescapedString.utf16.count)
+
+        // Add a custom attribute to the code block, so it can be detected later, e.g. when hit testing,
+        // since the styling of a code block and inline code can be identical
+        var attributes = self.attributes
+        attributes[.syntaxBlock] = NSNumber(value: true)
+
         attributedString.addAttributes(attributes,
                                        range: range)
         // If the previous character was a newline then parser doesn't have to worry about
@@ -123,3 +129,7 @@ open class CDMarkdownSyntax: CDMarkdownCommonElement {
         }
     }
 }
+
+public extension NSAttributedString.Key {
+    static let syntaxBlock: NSAttributedString.Key = .init("syntaxBlock")
+}