Add Composer#write_to_string

CHANGELOG.md

@@ -4,7 +4,8 @@
 
 * [HexaPDF::Task::MergeAcroForm] for merging AcroForm information for imported
   pages
-* [HexaPDF::Document#write_to_string] for easily writing a document to a String
+* [HexaPDF::Document#write_to_string] and [HexaPDF::Composer#write_to_string]
+  for easily writing a document to a String
 
 ### Changed
 

lib/hexapdf/composer.rb

@@ -231,6 +231,13 @@ def write(output, optimize: true, **options)
       @document.write(output, optimize: optimize, **options)
     end
 
+    # Writes the created PDF document to a string and returns that string.
+    #
+    # See HexaPDF::Document#write for details.
+    def write_to_string(optimize: true, **options)
+      @document.write_to_string(optimize: optimize, **options)
+    end
+
     # :call-seq:
     #    composer.style(name)                              -> style
     #    composer.style(name, base: :base, **properties)   -> style

test/hexapdf/test_composer.rb

@@ -63,6 +63,14 @@
     end
   end
 
+  it "writes the document to a string" do
+    pdf = HexaPDF::Composer.new
+    pdf.new_page
+    str = pdf.write_to_string
+    doc = HexaPDF::Document.new(io: StringIO.new(str))
+    assert_equal(2, doc.pages.count)
+  end
+
   describe "new_page" do
     it "creates a new page" do
       c = HexaPDF::Composer.new(page_size: [0, 0, 50, 100], margin: 10)