convenience child tag init

Sources/SwiftSgml/Tag.swift

@@ -21,7 +21,12 @@ open class Tag {
         self.node = Self.createNode()
         self.children = children
     }
-
+
+    /// initialize a new Tag with a single child tag
+    public convenience init(_ child: Tag) {
+        self.init([child])
+    }
+
     /// initialize a new Tag with children using a builder
     public convenience init(@TagBuilder _ builder: () -> [Tag]) {
         self.init(builder())

Tests/SwiftSgmlTests/TagTests.swift

@@ -0,0 +1,26 @@
+//
+//  File.swift
+//  
+//
+//  Created by Tibor Bodecs on 2022. 02. 24..
+//
+
+import XCTest
+@testable import SwiftSgml
+
+final class TagTests: XCTestCase {
+
+    func testConvenienceSingleTagInit() {
+
+        let doc = Document {
+            Root(Leaf("hello"))
+        }
+
+        XCTAssertEqual(DocumentRenderer().render(doc), """
+                            <root>
+                                <leaf>hello</leaf>
+                            </root>
+                            """)
+    }
+
+    }