diff --git a/packages/notus/lib/convert.dart b/packages/notus/lib/convert.dart
index b4b5f8263..47e92c0dc 100644
--- a/packages/notus/lib/convert.dart
+++ b/packages/notus/lib/convert.dart
@@ -14,4 +14,4 @@ export 'src/convert/markdown.dart';
 /// Markdown codec for Notus documents.
 const NotusMarkdownCodec notusMarkdown = NotusMarkdownCodec();
 
-const NotusHTMLCodec notusHTML = const NotusHTMLCodec();
+const NotusHTMLCodec notusHTML = NotusHTMLCodec();
diff --git a/packages/notus/lib/src/convert/html.dart b/packages/notus/lib/src/convert/html.dart
index 42b77678b..a418e734e 100644
--- a/packages/notus/lib/src/convert/html.dart
+++ b/packages/notus/lib/src/convert/html.dart
@@ -124,11 +124,11 @@ class _NotusHTMLEncoder extends Converter<Delta, String> {
 
   @override
   String convert(Delta input) {
-    final iterator = new DeltaIterator(input);
-    final buffer = new StringBuffer();
-    final lineBuffer = new StringBuffer();
+    final iterator = DeltaIterator(input);
+    final buffer = StringBuffer();
+    final lineBuffer = StringBuffer();
     NotusAttribute<String> currentBlockStyle;
-    NotusStyle currentInlineStyle = new NotusStyle();
+    NotusStyle currentInlineStyle = NotusStyle();
     List<String> currentBlockLines = [];
 
     void _handleBlock(NotusAttribute<String> blockStyle) {
@@ -222,7 +222,7 @@ class _NotusHTMLEncoder extends Converter<Delta, String> {
   }
 
   String _writeLine(String text, NotusStyle style) {
-    StringBuffer buffer = new StringBuffer();
+    StringBuffer buffer = StringBuffer();
     if (style.contains(NotusAttribute.heading)) {
       _writeAttribute(buffer, style.get(NotusAttribute.heading));
     }
@@ -284,7 +284,7 @@ class _NotusHTMLEncoder extends Converter<Delta, String> {
     } else if (attribute.key == NotusAttribute.embed.key) {
       _writeEmbedTag(buffer, attribute, close: close);
     } else {
-      throw new ArgumentError('Cannot handle $attribute');
+      throw ArgumentError('Cannot handle $attribute');
     }
   }
 
diff --git a/packages/notus/test/convert/html_test.dart b/packages/notus/test/convert/html_test.dart
index 47086afb9..d76ace154 100644
--- a/packages/notus/test/convert/html_test.dart
+++ b/packages/notus/test/convert/html_test.dart
@@ -82,9 +82,9 @@ void main() {
     test('decode intersecting inline ', () {
       final b = NotusAttribute.bold.toJson();
       final i = NotusAttribute.italic.toJson();
-      final bi = new Map<String, dynamic>.from(b);
+      final bi = Map<String, dynamic>.from(b);
       bi.addAll(i);
-      final delta = new Delta()
+      final delta = Delta()
         ..insert('This')
         ..insert('house', b)
         ..insert('is a', bi)
@@ -98,20 +98,20 @@ void main() {
 
     test('decode a tag', () {
       final l = NotusAttribute.link.fromString('http://foo.com');
-      final delta = new Delta()..insert('a tag', l.toJson())..insert("\n");
+      final delta = Delta()..insert('a tag', l.toJson())..insert("\n");
       final html = '<a href="http://foo.com">a tag</a>\n';
       final result = notusHTML.decode(html);
       expect(result, delta);
     });
 
     test('decode br tag', () {
-      final delta = new Delta()..insert('\n')..insert("\n");
+      final delta = Delta()..insert('\n')..insert("\n");
       final html = '<br>\n';
       final result = notusHTML.decode(html);
       expect(result, delta);
     });
     test('decode nested br tag ', () {
-      final delta = new Delta()..insert('<b>a<br></b>')..insert("\n");
+      final delta = Delta()..insert('<b>a<br></b>')..insert("\n");
       final html = '<b>a<br></b>\n';
       final result = notusHTML.decode(html);
       expect(result, delta);
@@ -169,9 +169,7 @@ void main() {
     });
     test('decode heading styles', () {
       runFor(NotusAttribute<int> attribute, String source, String html) {
-        final delta = new Delta()
-          ..insert(source)
-          ..insert('\n', attribute.toJson());
+        final delta = Delta()..insert(source)..insert('\n', attribute.toJson());
         final result = notusHTML.decode(html);
         expect(result, delta);
       }
@@ -184,7 +182,7 @@ void main() {
     test('decode heading styles with container attribute', () {
       runFor(NotusAttribute<int> attribute, String source, String html) {
         final attr = attribute.toJson();
-        final delta = new Delta()..insert(source)..insert('\n', attr);
+        final delta = Delta()..insert(source)..insert('\n', attr);
         final result = notusHTML.decode(html);
         expect(result.toString(), delta.toString());
       }
@@ -220,9 +218,7 @@ void main() {
 
     test('decode singe block', () {
       runFor(NotusAttribute<String> attribute, String source, String html) {
-        final delta = new Delta()
-          ..insert(source)
-          ..insert('\n', attribute.toJson());
+        final delta = Delta()..insert(source)..insert('\n', attribute.toJson());
         final result = notusHTML.decode(html);
         expect(result, delta);
       }
@@ -290,9 +286,9 @@ void main() {
     test('decode complex intersecting inline ', () {
       final b = NotusAttribute.bold.toJson();
       final i = NotusAttribute.italic.toJson();
-      final bi = new Map<String, dynamic>.from(b);
-      final bia = new Map<String, dynamic>.from(b);
-      final biaimage = new Map<String, dynamic>.from(b);
+      final bi = Map<String, dynamic>.from(b);
+      final bia = Map<String, dynamic>.from(b);
+      final biaimage = Map<String, dynamic>.from(b);
       final l = NotusAttribute.link.fromString('https://github.com').toJson();
       bi.addAll(i);
       bia.addAll(i);
@@ -381,7 +377,7 @@ void main() {
 
     test('encode bold italic', () {
       runFor(NotusAttribute<bool> attribute, String expected) {
-        final delta = new Delta()
+        final delta = Delta()
           ..insert('This ')
           ..insert('house', attribute.toJson())
           ..insert(' is a ')
@@ -399,10 +395,10 @@ void main() {
     test('encode intersecting inline styles', () {
       final b = NotusAttribute.bold.toJson();
       final i = NotusAttribute.italic.toJson();
-      final bi = new Map<String, dynamic>.from(b);
+      final bi = Map<String, dynamic>.from(b);
       bi.addAll(i);
 
-      final delta = new Delta()
+      final delta = Delta()
         ..insert('This ')
         ..insert('house', b)
         ..insert(' is a ', bi)
@@ -480,7 +476,7 @@ void main() {
     test('encode normalize inline styles', () {
       final b = NotusAttribute.bold.toJson();
       final i = NotusAttribute.italic.toJson();
-      final delta = new Delta()
+      final delta = Delta()
         ..insert('This')
         ..insert(' house ', b)
         ..insert('is a')
@@ -494,7 +490,7 @@ void main() {
     test('encode links', () {
       final b = NotusAttribute.bold.toJson();
       final link = NotusAttribute.link.fromString('https://github.com');
-      final delta = new Delta()
+      final delta = Delta()
         ..insert('This')
         ..insert(' house ', b)
         ..insert('is a')
@@ -508,9 +504,7 @@ void main() {
 
     test('encode heading styles', () {
       runFor(NotusAttribute<int> attribute, String source, String expected) {
-        final delta = new Delta()
-          ..insert(source)
-          ..insert('\n', attribute.toJson());
+        final delta = Delta()..insert(source)..insert('\n', attribute.toJson());
         final result = notusHTML.encode(delta);
         expect(result, expected);
       }
@@ -522,7 +516,7 @@ void main() {
     test('encode heading styles', () {
       runFor(NotusAttribute<int> attribute, String source, String expected) {
         final attr = attribute.toJson();
-        final delta = new Delta()..insert(source)..insert('\n', attr);
+        final delta = Delta()..insert(source)..insert('\n', attr);
         final result = notusHTML.encode(delta);
         expect(result, expected);
       }
@@ -630,7 +624,7 @@ void main() {
     });
     test('encode multiline blocks', () {
       runFor(NotusAttribute<String> attribute, String source, String expected) {
-        final delta = new Delta()
+        final delta = Delta()
           ..insert(source)
           ..insert('\n', attribute.toJson())
           ..insert(source)