Skip rendering Markdown comments

Sources/MarkdownUI/Parser/MarkdownParser.swift

@@ -60,6 +60,11 @@ extension BlockNode {
     case .codeBlock:
       self = .codeBlock(fenceInfo: unsafeNode.fenceInfo, content: unsafeNode.literal ?? "")
     case .htmlBlock:
+      // Don't render comments
+      let trimmedLiteral = unsafeNode.literal?.trimmingCharacters(in: .whitespacesAndNewlines)
+      if let trimmedLiteral, trimmedLiteral.hasPrefix("<!--") && trimmedLiteral.hasSuffix("-->") {
+        return nil
+      }
       self = .htmlBlock(content: unsafeNode.literal ?? "")
     case .paragraph:
       self = .paragraph(content: unsafeNode.children.compactMap(InlineNode.init(unsafeNode:)))

Tests/MarkdownUITests/MarkdownContentTests.swift

@@ -423,4 +423,22 @@ final class MarkdownContentTests: XCTestCase {
     )
     XCTAssertEqual(markdown, content.renderMarkdown())
   }
+
+  func testComment() {
+    // given
+    let markdown = """
+      <!--This is a comment-->
+      <!--
+        This is a
+        multiline comment
+      -->
+      """
+
+    // when
+    let content = MarkdownContent(markdown)
+
+    // then
+    XCTAssertEqual(MarkdownContent {}, content)
+    XCTAssertEqual("", content.renderMarkdown())
+  }
 }

Tests/MarkdownUITests/MarkdownTests.swift

@@ -342,5 +342,21 @@
 
       assertSnapshot(of: view, as: .image(layout: layout))
     }
+
+    func testComment() {
+      let view = Markdown {
+        #"""
+        This is rendered
+        <!--This is a comment-->
+        <!--
+          This is a multiline
+          comment
+        -->
+        So is this
+        """#
+      }.markdownSoftBreakMode(.lineBreak)
+
+      assertSnapshot(of: view, as: .image(layout: layout))
+    }
   }
 #endif