resolves #217 add support for Unicode characters in chapter IDs

CHANGELOG.adoc

@@ -8,6 +8,7 @@ For a detailed view of what has changed, refer to the {uri-repo}/commits/master[
 == Unreleased
 
 * drop unused dependencies: thread_safe, concurrent-ruby (#234)
+* add support for Unicode characters in chapter IDs (#217)
 * fix sample-book to be a valid book (#196)
 * require at least Asciidoctor 1.5.3 (#245)
 * fix the (in)famous `undefined method `to_ios'` when given a document that doesn't follow asciidoctor-epub3 rules (#7)

lib/asciidoctor-epub3.rb

@@ -6,3 +6,6 @@
 require_relative 'asciidoctor-epub3/ext'
 require_relative 'asciidoctor-epub3/converter'
 require_relative 'asciidoctor-epub3/packager'
+
+# We need to be able to write files with unicode names. See https://github.com/asciidoctor/asciidoctor-epub3/issues/217
+::Zip.unicode_names = true

spec/converter_spec.rb

@@ -28,5 +28,24 @@
           attributes: { 'ebook-format' => 'mobi' }
       expect(File).to exist(out_file)
     end
+
+    it 'converts chapter with unicode title to unicode filename' do
+      infile = fixture_file 'unicode/spine.adoc'
+      outfile = temp_file 'unicode.epub'
+      Asciidoctor.convert_file infile,
+          to_file: outfile,
+          backend: 'epub3',
+          header_footer: true,
+          mkdirs: true
+      prev_zip_encoding = Zip.force_entry_names_encoding
+      begin
+        Zip.force_entry_names_encoding = 'UTF-8'
+        Zip::File.open outfile do |zip|
+          expect(zip.find_entry('OEBPS/test-é.xhtml')).not_to be_nil
+        end
+      ensure
+        Zip.force_entry_names_encoding = prev_zip_encoding
+      end
+    end
   end
 end

spec/fixtures/unicode/reference.adoc

@@ -0,0 +1 @@
+= Test é

spec/fixtures/unicode/spine.adoc

@@ -0,0 +1,6 @@
+= Unicode book
+:doctype: book
+:idprefix:
+:idseparator: -
+
+include::reference.adoc[]