Migrated Jael

CHANGELOG.md

@@ -1,12 +1,12 @@
 # 4.0.0 (NNBD)
 * Changed Dart SDK requirements for all packages to ">=2.12.0 <3.0.0" to support NNBD. 
-* Migrated pretty_logging to 3.0.0 (0/0 tests)
+* Migrated pretty_logging to 3.0.0 (0/0 tests passed)
-* Migrated angel_http_exception to 3.0.0 (0/0 tests)
+* Migrated angel_http_exception to 3.0.0 (0/0 tests passed)
 * Moved angel_cli to https://github.com/dukefirehawk/cli (Not migrated)
-* Added code_buffer and migrated to 2.0.0 (16/16 tests)
+* Added code_buffer and migrated to 2.0.0 (16/16 tests passed)
-* Added combinator and migrated to 2.0.0 (16/16 tests)
+* Added combinator and migrated to 2.0.0 (16/16 tests passed)
 * Migrated angel_route to 5.0.0 (35/35 tests passed)
-* Migrated angel_model to 3.0.0 (0/0 tests)
+* Migrated angel_model to 3.0.0 (0/0 tests passed)
 * Migrated angel_container to 3.0.0 (55/55 tests passed)
 * Added merge_map and migrated to 2.0.0 (6/6 tests passed)
 * Added mock_request and migrated to 2.0.0 (0/0 tests)
@@ -19,7 +19,7 @@
 * Migrated angel_websocket to 4.0.0 (2/3 tests passed)
 * Updated test to 4.0.0 (1/1 test passed)
 * Added symbol_table and migrated to 2.0.0 (16/16 tests passed)
-* Updated jael to 3.0.0 (in progress)
+* Migrated jael to 4.0.0 (17/20 tests passed)
 * Updated jael_preprocessor to 3.0.0 (in progress)
 * Updated angel_jael to 3.0.0 (in progress)
 * Updated pub_sub to 3.0.0 (in progress)
@@ -30,27 +30,27 @@
 
 # 3.0.0 (Non NNBD)
 * Changed Dart SDK requirements for all packages to ">=2.10.0 <3.0.0"
-* Updated pretty_logging to 2.0.0
+* Updated pretty_logging to 2.0.0 (0/0 tests passed)
-* Updated angel_http_exception to 2.0.0
+* Updated angel_http_exception to 2.0.0 (0/0 tests passed)
 * Updated angel_cli to 3.0.0. (Rename not working)
-* Updated angel_route to 4.0.0
+* Updated angel_route to 4.0.0 (35/35 tests passed)
-* Updated angel_model to 2.0.0
+* Updated angel_model to 2.0.0 (0/0 tests passed)
-* Updated angel_container to 2.0.0
+* Updated angel_container to 2.0.0 (55/55 tests passed)
-* Updated angel_framework to 3.0.0
+* Updated angel_framework to 3.0.0 (151/151 tests passed)
-* Updated angel_auth to 3.0.0
+* Updated angel_auth to 3.0.0 (28/32 tests passed)
-* Updated angel_configuration to 3.0.0
+* Updated angel_configuration to 3.0.0 (6/8 tests passed)
-* Updated angel_validate to 3.0.0
+* Updated angel_validate to 3.0.0 (7/7 tests passed)
-* Added and updated json_god to 3.0.0
+* Added and updated json_god to 3.0.0 (7/7 tests passed)
-* Updated angel_client to 3.0.0
+* Updated angel_client to 3.0.0 (10/13 tests passed)
-* Updated angel_websocket to 3.0.0
+* Updated angel_websocket to 3.0.0 (3/3 tests passed)
-* Updated jael to 3.0.0
+* Updated jael to 3.0.0 (20/20 tests passed)
-* Updated jael_preprocessor to 3.0.0
+* Updated jael_preprocessor to 3.0.0 (5/5 tests passed)
-* Updated test to 3.0.0
+* Updated test to 3.0.0 (1/1 tests passed)
-* Updated angel_jael to 3.0.0 (Issue with 2 dependencies)
+* Updated angel_jael to 3.0.0 (1/1 tests passed, Issue with 2 dependencies)
-* Added pub_sub and updated to 3.0.0
+* Added pub_sub and updated to 3.0.0 (8/16 tests passed)
-* Updated production to 2.0.0
+* Updated production to 2.0.0 (0/0 tests passed)
-* Updated hot to 3.0.0
+* Updated hot to 3.0.0 (0/0 tests passed)
-* Updated static to 3.0.0
+* Updated static to 3.0.0 (12/12 tests passed)
 * Update basic-sdk-2.12.x boilerplate
 * Updated angel_serialize to 3.0.0
 * Updated angel_serialize_generator to 3.0.0

packages/jael/jael/bin/jaelfmt.dart

@@ -85,7 +85,6 @@ Future<void> formatStat(
       break;
     default:
       throw 'No file or directory found at "$path".';
-      break;
   }
 }
 
@@ -120,5 +119,9 @@ String? format(String? filename, String content, ArgResults argResults) {
       int.parse(argResults['tab-size'] as String),
       argResults['insert-spaces'] as bool?,
       int.parse(argResults['line-length'] as String));
+
+  if (doc == null) {
+    return null;
+  }
   return fmt.apply(doc);
 }

packages/jael/jael/lib/src/ast/array.dart

@@ -3,7 +3,7 @@ import 'expression.dart';
 import 'token.dart';
 
 class Array extends Expression {
-  final Token? lBracket, rBracket;
+  final Token lBracket, rBracket;
   final List<Expression> items;
 
   Array(this.lBracket, this.rBracket, this.items);
@@ -14,28 +14,28 @@ class Array extends Expression {
   @override
   FileSpan get span {
     return items
-        .fold<FileSpan?>(lBracket!.span, (out, i) => out!.expand(i.span!))!
+        .fold<FileSpan?>(lBracket.span, (out, i) => out!.expand(i.span))!
-        .expand(rBracket!.span!);
+        .expand(rBracket.span);
   }
 }
 
 class IndexerExpression extends Expression {
-  final Expression? target, indexer;
+  final Expression target, indexer;
-  final Token? lBracket, rBracket;
+  final Token lBracket, rBracket;
 
   IndexerExpression(this.target, this.lBracket, this.indexer, this.rBracket);
 
   @override
   FileSpan get span {
-    return target!.span!
+    return target.span
-        .expand(lBracket!.span!)
+        .expand(lBracket.span)
-        .expand(indexer!.span!)
+        .expand(indexer.span)
-        .expand(rBracket!.span!);
+        .expand(rBracket.span);
   }
 
   @override
   dynamic compute(scope) {
-    var a = target!.compute(scope), b = indexer!.compute(scope);
+    var a = target.compute(scope), b = indexer.compute(scope);
     return a[b];
   }
 }

packages/jael/jael/lib/src/ast/ast_node.dart

@@ -1,5 +1,5 @@
 import 'package:source_span/source_span.dart';
 
 abstract class AstNode {
-  FileSpan? get span;
+  FileSpan get span;
 }

packages/jael/jael/lib/src/ast/attribute.dart

@@ -15,13 +15,14 @@ class Attribute extends AstNode {
 
   bool get isRaw => nequ != null;
 
-  Expression? get nameNode => id ?? string;
+  Expression get nameNode => id ?? string!;
 
   String get name => string?.value ?? id!.name;
 
   @override
-  FileSpan? get span {
+  FileSpan get span {
-    if (equals == null) return nameNode!.span;
+    if (equals == null || value == null) return nameNode.span;
-    return nameNode!.span!.expand(equals?.span ?? nequ!.span!).expand(value!.span!);
+    //return nameNode.span.expand(equals!.span ?? nequ!.span).expand(value!.span);
+    return nameNode.span.expand(equals!.span).expand(value!.span);
   }
 }

packages/jael/jael/lib/src/ast/binary.dart

@@ -3,16 +3,16 @@ import 'expression.dart';
 import 'token.dart';
 
 class BinaryExpression extends Expression {
-  final Expression? left, right;
+  final Expression left, right;
-  final Token? operator;
+  final Token operator;
 
   BinaryExpression(this.left, this.operator, this.right);
 
   @override
-  compute(scope) {
+  dynamic compute(scope) {
-    var l = left!.compute(scope), r = right!.compute(scope);
+    var l = left.compute(scope), r = right.compute(scope);
 
-    switch (operator?.type) {
+    switch (operator.type) {
       case TokenType.asterisk:
         return l * r;
       case TokenType.slash:
@@ -38,10 +38,10 @@ class BinaryExpression extends Expression {
         return l ?? r;
       default:
         throw UnsupportedError(
-            'Unsupported binary operator: "${operator?.span?.text ?? "<null>"}".');
+            'Unsupported binary operator: "${operator.span.text ?? "<null>"}".');
     }
   }
 
   @override
-  FileSpan get span => left!.span!.expand(operator!.span!).expand(right!.span!);
+  FileSpan get span => left.span.expand(operator.span).expand(right.span);
 }

packages/jael/jael/lib/src/ast/call.dart

@@ -6,8 +6,8 @@ import 'identifier.dart';
 import 'token.dart';
 
 class Call extends Expression {
-  final Expression? target;
+  final Expression target;
-  final Token? lParen, rParen;
+  final Token lParen, rParen;
   final List<Expression> arguments;
   final List<NamedArgument> namedArguments;
 
@@ -17,24 +17,24 @@ class Call extends Expression {
   @override
   FileSpan get span {
     return arguments
-        .fold<FileSpan?>(target!.span, (out, a) => out!.expand(a.span!))!
+        .fold<FileSpan?>(target.span, (out, a) => out!.expand(a.span))!
         .expand(namedArguments.fold<FileSpan?>(
-            lParen!.span, (out, a) => out!.expand(a.span))!)
+            lParen.span, (out, a) => out!.expand(a.span))!)
-        .expand(rParen!.span!);
+        .expand(rParen.span);
   }
 
-  List computePositional(SymbolTable scope) =>
+  List computePositional(SymbolTable? scope) =>
       arguments.map((e) => e.compute(scope)).toList();
 
-  Map<Symbol, dynamic> computeNamed(SymbolTable scope) {
+  Map<Symbol, dynamic> computeNamed(SymbolTable? scope) {
     return namedArguments.fold<Map<Symbol, dynamic>>({}, (out, a) {
       return out..[Symbol(a.name.name)] = a.value.compute(scope);
     });
   }
 
   @override
-  compute(scope) {
+  dynamic compute(scope) {
-    var callee = target!.compute(scope);
+    var callee = target.compute(scope);
     var args = computePositional(scope);
     var named = computeNamed(scope);
 
@@ -44,13 +44,13 @@ class Call extends Expression {
 
 class NamedArgument extends AstNode {
   final Identifier name;
-  final Token? colon;
+  final Token colon;
   final Expression value;
 
   NamedArgument(this.name, this.colon, this.value);
 
   @override
   FileSpan get span {
-    return name.span!.expand(colon!.span!).expand(value.span!);
+    return name.span.expand(colon.span).expand(value.span);
   }
 }

packages/jael/jael/lib/src/ast/conditional.dart

@@ -3,29 +3,29 @@ import 'expression.dart';
 import 'token.dart';
 
 class Conditional extends Expression {
-  final Expression? condition, ifTrue, ifFalse;
+  final Expression condition, ifTrue, ifFalse;
-  final Token? question, colon;
+  final Token question, colon;
 
   Conditional(
       this.condition, this.question, this.ifTrue, this.colon, this.ifFalse);
 
   @override
   FileSpan get span {
-    return condition!.span!
+    return condition.span
-        .expand(question!.span!)
+        .expand(question.span)
-        .expand(ifTrue!.span!)
+        .expand(ifTrue.span)
-        .expand(colon!.span!)
+        .expand(colon.span)
-        .expand(ifFalse!.span!);
+        .expand(ifFalse.span);
   }
 
   @override
-  compute(scope) {
+  dynamic compute(scope) {
-    var v = condition!.compute(scope) as bool?;
+    var v = condition.compute(scope) as bool;
 
-    if (scope.resolve('!strict!')?.value == false) {
+    if (scope?.resolve('!strict!')?.value == false) {
       v = v == true;
     }
 
-    return v! ? ifTrue!.compute(scope) : ifFalse!.compute(scope);
+    return v ? ifTrue.compute(scope) : ifFalse.compute(scope);
   }
 }

packages/jael/jael/lib/src/ast/document.dart

@@ -12,33 +12,34 @@ class Document extends AstNode {
   Document(this.doctype, this.root);
 
   @override
-  FileSpan? get span {
+  FileSpan get span {
     if (doctype == null) return root.span;
-    return doctype!.span.expand(root.span!);
+    return doctype!.span.expand(root.span);
   }
 }
 
 class HtmlComment extends ElementChild {
-  final Token? htmlComment;
+  final Token htmlComment;
 
   HtmlComment(this.htmlComment);
 
   @override
-  FileSpan? get span => htmlComment!.span;
+  FileSpan get span => htmlComment.span;
 }
 
 class Text extends ElementChild {
-  final Token? text;
+  final Token text;
 
   Text(this.text);
 
   @override
-  FileSpan? get span => text!.span;
+  FileSpan get span => text.span;
 }
 
 class Doctype extends AstNode {
-  final Token? lt, doctype, gt;
+  final Token lt, doctype, gt;
-  final Identifier? html, public;
+  final Identifier html;
+  final Identifier? public;
   final StringLiteral? name, url;
 
   Doctype(this.lt, this.doctype, this.html, this.public, this.name, this.url,
@@ -46,15 +47,15 @@ class Doctype extends AstNode {
 
   @override
   FileSpan get span {
-    if (public == null) {
+    if (public == null || name == null || url == null) {
-      return lt!.span!.expand(doctype!.span!).expand(html!.span!).expand(gt!.span!);
+      return lt.span.expand(doctype.span).expand(html.span).expand(gt.span);
     }
-    return lt!.span!
+    return lt.span
-        .expand(doctype!.span!)
+        .expand(doctype.span)
-        .expand(html!.span!)
+        .expand(html.span)
-        .expand(public!.span!)
+        .expand(public!.span)
-        .expand(name!.span!)
+        .expand(name!.span)
-        .expand(url!.span!)
+        .expand(url!.span)
-        .expand(gt!.span!);
+        .expand(gt.span);
   }
 }

packages/jael/jael/lib/src/ast/element.dart

@@ -13,7 +13,7 @@ class TextNode extends ElementChild {
   TextNode(this.text);
 
   @override
-  FileSpan? get span => text.span;
+  FileSpan get span => text.span;
 }
 
 abstract class Element extends ElementChild {
@@ -44,10 +44,13 @@ abstract class Element extends ElementChild {
 }
 
 class SelfClosingElement extends Element {
-  final Token? lt, slash, gt;
+  final Token? slash;
+  final Token lt, gt;
 
+  @override
   final Identifier tagName;
 
+  @override
   final Iterable<Attribute> attributes;
 
   @override
@@ -59,20 +62,19 @@ class SelfClosingElement extends Element {
   @override
   FileSpan get span {
     var start = attributes.fold<FileSpan>(
-        lt!.span!.expand(tagName.span!), (out, a) => out.expand(a.span!));
+        lt.span.expand(tagName.span), (out, a) => out.expand(a.span));
     return slash != null
-        ? start.expand(slash!.span!).expand(gt!.span!)
+        ? start.expand(slash!.span).expand(gt.span)
-        : start.expand(gt!.span!);
+        : start.expand(gt.span);
   }
 }
 
 class RegularElement extends Element {
-  final Token? lt, gt, lt2, slash, gt2;
+  final Token? gt2;
+  final Token lt2, slash, lt, gt;
 
   final Identifier tagName, tagName2;
-
   final Iterable<Attribute> attributes;
-
   final Iterable<ElementChild> children;
 
   RegularElement(this.lt, this.tagName, this.attributes, this.gt, this.children,
@@ -82,16 +84,16 @@ class RegularElement extends Element {
   FileSpan get span {
     var openingTag = attributes
         .fold<FileSpan>(
-            lt!.span!.expand(tagName.span!), (out, a) => out.expand(a.span!))
+            lt.span.expand(tagName.span), (out, a) => out.expand(a.span))
-        .expand(gt!.span!);
+        .expand(gt.span);
 
     if (gt2 == null) return openingTag;
 
     return children
-        .fold<FileSpan>(openingTag, (out, c) => out.expand(c.span!))
+        .fold<FileSpan>(openingTag, (out, c) => out.expand(c.span))
-        .expand(lt2!.span!)
+        .expand(lt2.span)
-        .expand(slash!.span!)
+        .expand(slash.span)
-        .expand(tagName2.span!)
+        .expand(tagName2.span)
-        .expand(gt2!.span!);
+        .expand(gt2!.span);
   }
 }

packages/jael/jael/lib/src/ast/error.dart

@@ -3,15 +3,15 @@ import 'package:source_span/source_span.dart';
 class JaelError extends Error {
   final JaelErrorSeverity severity;
   final String message;
-  final FileSpan? span;
+  final FileSpan span;
 
   JaelError(this.severity, this.message, this.span);
 
   @override
   String toString() {
     var label = severity == JaelErrorSeverity.warning ? 'warning' : 'error';
-    return '$label: ${span!.start.toolString}: $message\n' +
+    return '$label: ${span.start.toolString}: $message\n' +
-        span!.highlight(color: true);
+        span.highlight(color: true);
   }
 }
 

packages/jael/jael/lib/src/ast/expression.dart

@@ -4,30 +4,29 @@ import 'ast_node.dart';
 import 'token.dart';
 
 abstract class Expression extends AstNode {
-  dynamic compute(SymbolTable scope);
+  dynamic compute(SymbolTable? scope);
 }
 
 abstract class Literal extends Expression {}
 
 class Negation extends Expression {
-  final Token? exclamation;
+  final Token exclamation;
-  final Expression? expression;
+  final Expression expression;
 
   Negation(this.exclamation, this.expression);
 
   @override
   FileSpan get span {
-    return exclamation!.span!.expand(expression!.span!);
+    return exclamation.span.expand(expression.span);
   }
 
   @override
-  compute(SymbolTable scope) {
+  bool compute(SymbolTable? scope) {
-    var v = expression!.compute(scope) as bool?;
+    var v = expression.compute(scope) as bool;
-
+    if (scope?.resolve('!strict!')?.value == false) {
-    if (scope.resolve('!strict!')?.value == false) {
       v = v == true;
     }
 
-    return !v!;
+    return !v;
   }
 }

packages/jael/jael/lib/src/ast/identifier.dart

@@ -4,12 +4,12 @@ import 'expression.dart';
 import 'token.dart';
 
 class Identifier extends Expression {
-  final Token? id;
+  final Token id;
 
   Identifier(this.id);
 
   @override
-  compute(SymbolTable scope) {
+  dynamic compute(SymbolTable? scope) {
     switch (name) {
       case 'null':
         return null;
@@ -18,30 +18,30 @@ class Identifier extends Expression {
       case 'false':
         return false;
       default:
-        var symbol = scope.resolve(name);
+        var symbol = scope?.resolve(name);
         if (symbol == null) {
-          if (scope.resolve('!strict!')?.value == false) return null;
+          if (scope?.resolve('!strict!')?.value == false) return null;
           throw ArgumentError('The name "$name" does not exist in this scope.');
         }
-        return scope.resolve(name)!.value;
+        return scope?.resolve(name)!.value;
     }
   }
 
-  String get name => id!.span!.text;
+  String get name => id.span.text ?? '';
 
   @override
-  FileSpan? get span => id!.span;
+  FileSpan get span => id.span;
 }
 
 class SyntheticIdentifier extends Identifier {
   @override
   final String name;
 
-  SyntheticIdentifier(this.name, [Token? token]) : super(token);
+  SyntheticIdentifier(this.name, [Token? token]) : super(token!);
 
   @override
-  FileSpan? get span {
+  FileSpan get span {
-    if (id != null) return id!.span;
+    return id.span;
-    throw UnsupportedError('Cannot get the span of a SyntheticIdentifier.');
+    //throw UnsupportedError('Cannot get the span of a SyntheticIdentifier.');
   }
 }

packages/jael/jael/lib/src/ast/interpolation.dart

@@ -4,15 +4,15 @@ import 'expression.dart';
 import 'token.dart';
 
 class Interpolation extends ElementChild {
-  final Token? doubleCurlyL, doubleCurlyR;
+  final Token doubleCurlyL, doubleCurlyR;
   final Expression expression;
 
   Interpolation(this.doubleCurlyL, this.expression, this.doubleCurlyR);
 
-  bool get isRaw => doubleCurlyL!.span!.text.endsWith('-');
+  bool get isRaw => doubleCurlyL.span.text?.endsWith('-') ?? false;
 
   @override
   FileSpan get span {
-    return doubleCurlyL!.span!.expand(expression.span!).expand(doubleCurlyR!.span!);
+    return doubleCurlyL.span.expand(expression.span).expand(doubleCurlyR.span);
   }
 }

packages/jael/jael/lib/src/ast/map.dart

@@ -5,26 +5,26 @@ import 'identifier.dart';
 import 'token.dart';
 
 class MapLiteral extends Literal {
-  final Token? lCurly, rCurly;
+  final Token lCurly, rCurly;
   final List<KeyValuePair> pairs;
 
   MapLiteral(this.lCurly, this.pairs, this.rCurly);
 
   @override
-  compute(scope) {
+  Map compute(scope) {
     return pairs.fold<Map>({}, (out, p) {
       var key, value;
 
       if (p.colon == null) {
         if (p.key is! Identifier) {
-          key = value = p.key!.compute(scope);
+          key = value = p.key.compute(scope);
         } else {
           key = (p.key as Identifier).name;
-          value = p.key!.compute(scope);
+          value = p.key.compute(scope);
         }
       } else {
-        key = p.key!.compute(scope);
+        key = p.key.compute(scope);
-        value = p.value!.compute(scope);
+        value = p.value?.compute(scope);
       }
 
       return out..[key] = value;
@@ -34,20 +34,22 @@ class MapLiteral extends Literal {
   @override
   FileSpan get span {
     return pairs
-        .fold<FileSpan?>(lCurly!.span, (out, p) => out!.expand(p.span!))!
+        .fold<FileSpan?>(lCurly.span, (out, p) => out?.expand(p.span))!
-        .expand(rCurly!.span!);
+        .expand(rCurly.span);
   }
 }
 
 class KeyValuePair extends AstNode {
-  final Expression? key, value;
+  final Expression key;
+  final Expression? value;
+
   final Token? colon;
 
   KeyValuePair(this.key, this.colon, this.value);
 
   @override
-  FileSpan? get span {
+  FileSpan get span {
-    if (colon == null) return key!.span;
+    if (colon == null || value == null) return key.span;
-    return colon!.span!.expand(colon!.span!).expand(value!.span!);
+    return colon!.span.expand(colon!.span).expand(value!.span);
   }
 }

packages/jael/jael/lib/src/ast/member.dart

@@ -6,19 +6,19 @@ import 'identifier.dart';
 import 'token.dart';
 
 class MemberExpression extends Expression {
-  final Expression? expression;
+  final Expression expression;
-  final Token? op;
+  final Token op;
   final Identifier name;
 
   MemberExpression(this.expression, this.op, this.name);
 
   @override
-  compute(SymbolTable scope) {
+  dynamic compute(SymbolTable? scope) {
-    var target = expression!.compute(scope);
+    var target = expression.compute(scope);
-    if (op!.span!.text == '?.' && target == null) return null;
+    if (op.span.text == '?.' && target == null) return null;
     return reflect(target).getField(Symbol(name.name)).reflectee;
   }
 
   @override
-  FileSpan get span => expression!.span!.expand(op!.span!).expand(name.span!);
+  FileSpan get span => expression.span.expand(op.span).expand(name.span);
 }

packages/jael/jael/lib/src/ast/new.dart

@@ -6,17 +6,17 @@ import 'member.dart';
 import 'token.dart';
 
 class NewExpression extends Expression {
-  final Token? $new;
+  final Token $new;
   final Call call;
 
   NewExpression(this.$new, this.call);
 
   @override
-  FileSpan get span => $new!.span!.expand(call.span);
+  FileSpan get span => $new.span.expand(call.span);
 
   @override
-  compute(scope) {
+  dynamic compute(scope) {
-    var targetType = call.target!.compute(scope);
+    var targetType = call.target.compute(scope);
     var positional = call.computePositional(scope);
     var named = call.computeNamed(scope);
     var name = '';

packages/jael/jael/lib/src/ast/number.dart

@@ -4,13 +4,13 @@ import 'expression.dart';
 import 'token.dart';
 
 class NumberLiteral extends Literal {
-  final Token? number;
+  final Token number;
   num? _value;
 
   NumberLiteral(this.number);
 
   @override
-  FileSpan? get span => number!.span;
+  FileSpan get span => number.span;
 
   static num parse(String value) {
     var e = value.indexOf('E');
@@ -24,24 +24,30 @@ class NumberLiteral extends Literal {
   }
 
   @override
-  compute(scope) {
+  num compute(scope) {
-    return _value ??= parse(number!.span!.text);
+    if (number.span.text == null) {
+      return 0;
+    }
+    return _value ??= parse(number.span.text!);
   }
 }
 
 class HexLiteral extends Literal {
-  final Token? hex;
+  final Token hex;
   num? _value;
 
   HexLiteral(this.hex);
 
   @override
-  FileSpan? get span => hex!.span;
+  FileSpan get span => hex.span;
 
   static num parse(String value) => int.parse(value.substring(2), radix: 16);
 
   @override
-  compute(scope) {
+  num compute(scope) {
-    return _value ??= parse(hex!.span!.text);
+    if (hex.span.text == null) {
+      return 0;
+    }
+    return _value ??= parse(hex.span.text!);
   }
 }

packages/jael/jael/lib/src/ast/string.dart

@@ -6,17 +6,21 @@ import 'expression.dart';
 import 'token.dart';
 
 class StringLiteral extends Literal {
-  final Token? string;
+  final Token string;
   final String value;
 
   StringLiteral(this.string, this.value);
 
   static String parseValue(Token string) {
-    var text = string.span!.text.substring(1, string.span!.text.length - 1);
-    var codeUnits = text.codeUnits;
     var buf = StringBuffer();
+    if (string.span.text == null) {
+      return buf.toString();
+    }
 
-    for (int i = 0; i < codeUnits.length; i++) {
+    var text = string.span.text!.substring(1, string.span.text!.length - 1);
+    var codeUnits = text.codeUnits;
+
+    for (var i = 0; i < codeUnits.length; i++) {
       var ch = codeUnits[i];
 
       if (ch == $backslash) {
@@ -66,10 +70,10 @@ class StringLiteral extends Literal {
   }
 
   @override
-  compute(SymbolTable scope) {
+  String compute(SymbolTable? scope) {
     return value;
   }
 
   @override
-  FileSpan? get span => string!.span;
+  FileSpan get span => string.span;
 }

packages/jael/jael/lib/src/ast/token.dart

@@ -2,14 +2,14 @@ import 'package:source_span/source_span.dart';
 
 class Token {
   final TokenType type;
-  final FileSpan? span;
+  final FileSpan span;
   final Match? match;
 
   Token(this.type, this.span, this.match);
 
   @override
   String toString() {
-    return '${span!.start.toolString}: "${span!.text}" => $type';
+    return '${span.start.toolString}: "${span.text}" => $type';
   }
 }
 

packages/jael/jael/lib/src/formatter.dart

@@ -5,13 +5,13 @@ class JaelFormatter {
   final num tabSize;
   final bool? insertSpaces;
   final int maxLineLength;
-  var _buffer = StringBuffer();
+  final _buffer = StringBuffer();
   int _level = 0;
   String? _spaces;
 
   static String _spaceString(int tabSize) {
     var b = StringBuffer();
-    for (int i = 0; i < tabSize; i++) {
+    for (var i = 0; i < tabSize; i++) {
       b.write(' ');
     }
     return b.toString();
@@ -30,34 +30,34 @@ class JaelFormatter {
   }
 
   void _applySpacing() {
-    for (int i = 0; i < _level; i++) {
+    for (var i = 0; i < _level; i++) {
       _buffer.write(_spaces);
     }
   }
 
   int get _spaceLength {
     var out = 0;
-    for (int i = 0; i < _level; i++) {
+    for (var i = 0; i < _level; i++) {
       out += _spaces!.length;
     }
     return out;
   }
 
-  String apply(Document? document) {
+  String apply(Document document) {
-    if (document?.doctype != null) {
+    if (document.doctype != null) {
       _buffer.write('<!doctype');
 
-      if (document!.doctype!.html != null) _buffer.write(' html');
+      if (document.doctype?.html != null) _buffer.write(' html');
-      if (document.doctype!.public != null) _buffer.write(' public');
+      if (document.doctype?.public != null) _buffer.write(' public');
 
-      if (document.doctype!.url != null) {
+      if (document.doctype?.url != null) {
         _buffer.write('${document.doctype!.url}');
       }
 
       _buffer.writeln('>');
     }
 
-    _formatChild(document?.root, 0);
+    _formatChild(document.root, 0);
 
     return _buffer.toString().trim();
   }
@@ -72,11 +72,11 @@ class JaelFormatter {
       var b = StringBuffer('{{');
       if (child.isRaw) b.write('-');
       b.write(' ');
-      b.write(child.expression.span!.text.trim());
+      b.write(child.expression.span.text?.trim());
       b.write(' }}');
       s = b.toString();
     } else {
-      s = child.span!.text;
+      s = child.span.text ?? '';
     }
     if (isFirst) {
       s = s.trimLeft();
@@ -186,7 +186,7 @@ class JaelFormatter {
       } else {
         if (attr.nequ != null) b.write('!=');
         if (attr.equals != null) b.write('=');
-        b.write(attr.value!.span!.text);
+        b.write(attr.value!.span.text);
       }
     }
     return b.toString();

packages/jael/jael/lib/src/renderer.dart

@@ -1,6 +1,7 @@
 import 'dart:convert';
 import 'package:code_buffer/code_buffer.dart';
 import 'package:collection/collection.dart' show IterableExtension;
+import 'package:source_span/source_span.dart';
 import 'package:symbol_table/symbol_table.dart';
 import 'ast/ast.dart';
 import 'text/parser.dart';
@@ -8,7 +9,7 @@ import 'text/scanner.dart';
 
 /// Parses a Jael document.
 Document? parseDocument(String text,
-    {sourceUrl, bool asDSX = false, void onError(JaelError error)?}) {
+    {sourceUrl, bool asDSX = false, void Function(JaelError error)? onError}) {
   var scanner = scan(text, sourceUrl: sourceUrl, asDSX: asDSX);
 
   //scanner.tokens.forEach(print);
@@ -56,12 +57,12 @@ class Renderer {
         ..writeln('<li>')
         ..indent()
         ..writeln(
-            '<b>$type:</b> ${error.span!.start.toolString}: ${error.message}')
+            '<b>$type:</b> ${error.span.start.toolString}: ${error.message}')
         ..writeln('<br>')
         ..writeln(
           '<span style="color: red;">' +
               htmlEscape
-                  .convert(error.span!.highlight(color: false))
+                  .convert(error.span.highlight(color: false))
                   .replaceAll('\n', '<br>') +
               '</span>',
         )
@@ -161,7 +162,7 @@ class Renderer {
       buffer.writeln('>');
       buffer.indent();
 
-      for (int i = 0; i < element.children.length; i++) {
+      for (var i = 0; i < element.children.length; i++) {
         var child = element.children.elementAt(i);
         renderElementChild(element, child, buffer, childScope, html5, i,
             element.children.length);
@@ -278,7 +279,7 @@ class Renderer {
           ?.value
           ?.compute(scope);
       if (comparison == value) {
-        for (int i = 0; i < child.children.length; i++) {
+        for (var i = 0; i < child.children.length; i++) {
           var c = child.children.elementAt(i);
           renderElementChild(
               element, c, buffer, scope, html5, i, child.children.length);
@@ -303,11 +304,11 @@ class Renderer {
       SymbolTable scope, bool html5, int index, int total) {
     if (child is Text && parent.tagName.name != 'textarea') {
       if (index == 0) {
-        buffer.write(child.span!.text.trimLeft());
+        buffer.write(child.span.text?.trimLeft());
       } else if (index == total - 1) {
-        buffer.write(child.span!.text.trimRight());
+        buffer.write(child.span.text?.trimRight());
       } else {
-        buffer.write(child.span!.text);
+        buffer.write(child.span.text);
       }
     } else if (child is Interpolation) {
       var value = child.expression.compute(scope);
@@ -369,7 +370,7 @@ class Renderer {
     }
 
     if (renderAs == false) {
-      for (int i = 0; i < template!.children.length; i++) {
+      for (var i = 0; i < template!.children.length; i++) {
         var child = template.children.elementAt(i);
         renderElementChild(
             element, child, buffer, scope, html5, i, element.children.length);

packages/jael/jael/lib/src/text/parselet/infix.dart

@@ -28,12 +28,12 @@ class ConditionalParselet implements InfixParselet {
   const ConditionalParselet();
 
   @override
-  Expression? parse(Parser parser, Expression? left, Token? token) {
+  Expression? parse(Parser parser, Expression left, Token token) {
     var ifTrue = parser.parseExpression(0);
 
     if (ifTrue == null) {
       parser.errors.add(JaelError(JaelErrorSeverity.error,
-          'Missing expression in conditional expression.', token!.span));
+          'Missing expression in conditional expression.', token.span));
       return null;
     }
 
@@ -48,7 +48,7 @@ class ConditionalParselet implements InfixParselet {
 
     if (ifFalse == null) {
       parser.errors.add(JaelError(JaelErrorSeverity.error,
-          'Missing expression in conditional expression.', colon!.span));
+          'Missing expression in conditional expression.', colon.span));
       return null;
     }
 
@@ -57,19 +57,20 @@ class ConditionalParselet implements InfixParselet {
 }
 
 class BinaryParselet implements InfixParselet {
+  @override
   final int precedence;
 
   const BinaryParselet(this.precedence);
 
   @override
-  Expression? parse(Parser parser, Expression? left, Token? token) {
+  Expression? parse(Parser parser, Expression left, Token token) {
     var right = parser.parseExpression(precedence);
 
     if (right == null) {
-      if (token!.type != TokenType.gt) {
+      if (token.type != TokenType.gt) {
         parser.errors.add(JaelError(
             JaelErrorSeverity.error,
-            'Missing expression after operator "${token.span!.text}", following expression ${left!.span!.text}.',
+            'Missing expression after operator "${token.span.text}", following expression ${left.span.text}.',
             token.span));
       }
       return null;
@@ -86,10 +87,10 @@ class CallParselet implements InfixParselet {
   int get precedence => 19;
 
   @override
-  Expression? parse(Parser parser, Expression? left, Token? token) {
+  Expression? parse(Parser parser, Expression left, Token token) {
-    List<Expression> arguments = [];
+    var arguments = <Expression>[];
-    List<NamedArgument> namedArguments = [];
+    var namedArguments = <NamedArgument>[];
-    Expression? argument = parser.parseExpression(0);
+    var argument = parser.parseExpression(0);
 
     while (argument != null) {
       arguments.add(argument);
@@ -98,7 +99,7 @@ class CallParselet implements InfixParselet {
       argument = parser.parseExpression(0);
     }
 
-    NamedArgument? namedArgument = parser.parseNamedArgument();
+    var namedArgument = parser.parseNamedArgument();
 
     while (namedArgument != null) {
       namedArguments.add(namedArgument);
@@ -109,7 +110,7 @@ class CallParselet implements InfixParselet {
 
     if (!parser.next(TokenType.rParen)) {
       var lastSpan = arguments.isEmpty ? null : arguments.last.span;
-      lastSpan ??= token!.span;
+      lastSpan ??= token.span;
       parser.errors.add(JaelError(JaelErrorSeverity.error,
           'Missing ")" after argument list.', lastSpan));
       return null;
@@ -126,12 +127,12 @@ class IndexerParselet implements InfixParselet {
   int get precedence => 19;
 
   @override
-  Expression? parse(Parser parser, Expression? left, Token? token) {
+  Expression? parse(Parser parser, Expression left, Token token) {
     var indexer = parser.parseExpression(0);
 
     if (indexer == null) {
       parser.errors.add(JaelError(
-          JaelErrorSeverity.error, 'Missing expression after "[".', left!.span));
+          JaelErrorSeverity.error, 'Missing expression after "[".', left.span));
       return null;
     }
 
@@ -152,12 +153,12 @@ class MemberParselet implements InfixParselet {
   int get precedence => 19;
 
   @override
-  Expression? parse(Parser parser, Expression? left, Token? token) {
+  Expression? parse(Parser parser, Expression left, Token token) {
     var name = parser.parseIdentifier();
 
     if (name == null) {
       parser.errors.add(JaelError(JaelErrorSeverity.error,
-          'Expected the name of a property following "."', token!.span));
+          'Expected the name of a property following "."', token.span));
       return null;
     }
 

packages/jael/jael/lib/src/text/parselet/parselet.dart

@@ -6,10 +6,10 @@ part 'infix.dart';
 part 'prefix.dart';
 
 abstract class PrefixParselet {
-  Expression? parse(Parser parser, Token? token);
+  Expression? parse(Parser parser, Token token);
 }
 
 abstract class InfixParselet {
   int get precedence;
-  Expression? parse(Parser parser, Expression? left, Token? token);
+  Expression? parse(Parser parser, Expression left, Token token);
 }

packages/jael/jael/lib/src/text/parselet/prefix.dart

@@ -16,15 +16,15 @@ class NotParselet implements PrefixParselet {
   const NotParselet();
 
   @override
-  Expression parse(Parser parser, Token? token) {
+  Expression parse(Parser parser, Token token) {
     var expression = parser.parseExpression(0);
 
     if (expression == null) {
       parser.errors.add(JaelError(JaelErrorSeverity.error,
-          'Missing expression after "!" in negation expression.', token!.span));
+          'Missing expression after "!" in negation expression.', token.span));
     }
 
-    return Negation(token, expression);
+    return Negation(token, expression!);
   }
 }
 
@@ -32,7 +32,7 @@ class NewParselet implements PrefixParselet {
   const NewParselet();
 
   @override
-  Expression? parse(Parser parser, Token? token) {
+  Expression? parse(Parser parser, Token token) {
     var call = parser.parseExpression(0);
 
     if (call == null) {
@@ -57,31 +57,31 @@ class NumberParselet implements PrefixParselet {
   const NumberParselet();
 
   @override
-  Expression parse(Parser parser, Token? token) => NumberLiteral(token);
+  Expression parse(Parser parser, Token token) => NumberLiteral(token);
 }
 
 class HexParselet implements PrefixParselet {
   const HexParselet();
 
   @override
-  Expression parse(Parser parser, Token? token) => HexLiteral(token);
+  Expression parse(Parser parser, Token token) => HexLiteral(token);
 }
 
 class StringParselet implements PrefixParselet {
   const StringParselet();
 
   @override
-  Expression parse(Parser parser, Token? token) =>
+  Expression parse(Parser parser, Token token) =>
-      StringLiteral(token, StringLiteral.parseValue(token!));
+      StringLiteral(token, StringLiteral.parseValue(token));
 }
 
 class ArrayParselet implements PrefixParselet {
   const ArrayParselet();
 
   @override
-  Expression? parse(Parser parser, Token? token) {
+  Expression? parse(Parser parser, Token token) {
-    List<Expression> items = [];
+    var items = <Expression>[];
-    Expression? item = parser.parseExpression(0);
+    var item = parser.parseExpression(0);
 
     while (item != null) {
       items.add(item);
@@ -92,7 +92,7 @@ class ArrayParselet implements PrefixParselet {
 
     if (!parser.next(TokenType.rBracket)) {
       var lastSpan = items.isEmpty ? null : items.last.span;
-      lastSpan ??= token!.span;
+      lastSpan ??= token.span;
       parser.errors.add(JaelError(JaelErrorSeverity.error,
           'Missing "]" to terminate array literal.', lastSpan));
       return null;
@@ -106,7 +106,7 @@ class MapParselet implements PrefixParselet {
   const MapParselet();
 
   @override
-  Expression? parse(Parser parser, Token? token) {
+  Expression? parse(Parser parser, Token token) {
     var pairs = <KeyValuePair>[];
     var pair = parser.parseKeyValuePair();
 
@@ -118,7 +118,7 @@ class MapParselet implements PrefixParselet {
     }
 
     if (!parser.next(TokenType.rCurly)) {
-      var lastSpan = pairs.isEmpty ? token!.span : pairs.last.span;
+      var lastSpan = pairs.isEmpty ? token.span : pairs.last.span;
       parser.errors.add(JaelError(
           JaelErrorSeverity.error, 'Missing "}" in map literal.', lastSpan));
       return null;
@@ -132,7 +132,7 @@ class IdentifierParselet implements PrefixParselet {
   const IdentifierParselet();
 
   @override
-  Expression parse(Parser parser, Token? token) => Identifier(token);
+  Expression parse(Parser parser, Token token) => Identifier(token);
 }
 
 class ParenthesisParselet implements PrefixParselet {

packages/jael/jael/lib/src/text/parser.dart

@@ -7,12 +7,12 @@ class Parser {
   final Scanner scanner;
   final bool asDSX;
 
-  Token? _current;
+  late Token _current;
   int _index = -1;
 
   Parser(this.scanner, {this.asDSX = false});
 
-  Token? get current => _current;
+  Token get current => _current;
 
   int _nextPrecedence() {
     var tok = peek();
@@ -68,8 +68,11 @@ class Parser {
 
   StringLiteral? implicitString() {
     if (next(TokenType.string)) {
-      return prefixParselets[TokenType.string]!.parse(this, _current)
+      var result = prefixParselets[TokenType.string]?.parse(this, _current);
-          as StringLiteral?;
+      if (result != null) {
+        return result as StringLiteral;
+      }
+      return null;
     }
     /*else if (next(TokenType.text)) {
 
@@ -86,12 +89,14 @@ class Parser {
       _index--;
       return null;
     }
-    var doctype = _current, html = parseIdentifier() as Token?;
+    var doctype = _current;
-    if (html?.span?.text.toLowerCase() != 'html') {
+    var html = parseIdentifier();
+    if (html == null || html.span.text?.toLowerCase() != 'html') {
       errors.add(JaelError(
           JaelErrorSeverity.error,
           'Expected "html" in doctype declaration.',
-          html?.span ?? doctype!.span));
+          html?.span ?? doctype.span));
+
       return null;
     }
 
@@ -99,19 +104,23 @@ class Parser {
     if (public == null) {
       if (!next(TokenType.gt)) {
         errors.add(JaelError(JaelErrorSeverity.error,
-            'Expected ">" in doctype declaration.', html!.span));
+            'Expected ">" in doctype declaration.', html.span));
+        // ?? doctype.span));
         return null;
       }
 
-      return Doctype(
+      return Doctype(lt, doctype, html, null, null, null, _current);
-          lt, doctype, html as Identifier?, null, null, null, _current);
     }
 
-    if (public.span?.text.toLowerCase() != 'public') {
+    if (public.span.text?.toLowerCase() != 'public') {
-      errors.add(JaelError(
+      //errors.add(JaelError(
-          JaelErrorSeverity.error,
+      //    JaelErrorSeverity.error,
-          'Expected "public" in doctype declaration.',
+      //    'Expected "public" in doctype declaration.',
-          public.span ?? html!.span));
+      //    public!.span ?? html?.span));
+
+      errors.add(JaelError(JaelErrorSeverity.error,
+          'Expected "public" in doctype declaration.', public.span));
+
       return null;
     }
 
@@ -123,24 +132,23 @@ class Parser {
       return null;
     }
 
-    var name = stringParser!.parse(this, _current) as StringLiteral?;
+    var name = stringParser?.parse(this, _current) as StringLiteral;
 
     if (!next(TokenType.string)) {
       errors.add(JaelError(JaelErrorSeverity.error,
-          'Expected string in doctype declaration.', name!.span));
+          'Expected string in doctype declaration.', name.span));
       return null;
     }
 
-    var url = stringParser.parse(this, _current) as StringLiteral?;
+    var url = stringParser?.parse(this, _current) as StringLiteral;
 
     if (!next(TokenType.gt)) {
       errors.add(JaelError(JaelErrorSeverity.error,
-          'Expected ">" in doctype declaration.', url!.span));
+          'Expected ">" in doctype declaration.', url.span));
       return null;
     }
 
-    return Doctype(
+    return Doctype(lt, doctype, html, public, name, url, _current);
-        lt, doctype, html as Identifier?, public, name, url, _current);
   }
 
   ElementChild? parseElementChild() =>
@@ -162,7 +170,7 @@ class Parser {
 
     if (expression == null) {
       errors.add(JaelError(JaelErrorSeverity.error,
-          'Missing expression in interpolation.', doubleCurlyL!.span));
+          'Missing expression in interpolation.', doubleCurlyL.span));
       return null;
     }
 
@@ -190,7 +198,7 @@ class Parser {
 
     if (tagName == null) {
       errors.add(
-          JaelError(JaelErrorSeverity.error, 'Missing tag name.', lt!.span));
+          JaelError(JaelErrorSeverity.error, 'Missing tag name.', lt.span));
       return null;
     }
 
@@ -208,7 +216,7 @@ class Parser {
 
       if (!next(TokenType.gt)) {
         errors.add(JaelError(JaelErrorSeverity.error,
-            'Missing ">" in self-closing "${tagName.name}" tag.', slash!.span));
+            'Missing ">" in self-closing "${tagName.name}" tag.', slash.span));
         return null;
       }
 
@@ -252,7 +260,7 @@ class Parser {
 
     if (!next(TokenType.slash)) {
       errors.add(JaelError(JaelErrorSeverity.error,
-          'Missing "/" in "${tagName.name}" closing tag.', lt2!.span));
+          'Missing "/" in "${tagName.name}" closing tag.', lt2.span));
       return null;
     }
 
@@ -263,15 +271,15 @@ class Parser {
       errors.add(JaelError(
           JaelErrorSeverity.error,
           'Missing "${tagName.name}" in "${tagName.name}" closing tag.',
-          slash!.span));
+          slash.span));
       return null;
     }
 
     if (tagName2.name != tagName.name) {
       errors.add(JaelError(
           JaelErrorSeverity.error,
-          'Mismatched closing tags. Expected "${tagName.span!.text}"; got "${tagName2.name}" instead.',
+          'Mismatched closing tags. Expected "${tagName.span.text}"; got "${tagName2.name}" instead.',
-          lt2!.span));
+          lt2.span));
       return null;
     }
 
@@ -292,7 +300,7 @@ class Parser {
     if ((id = parseIdentifier()) != null) {
       // Nothing
     } else if (next(TokenType.string)) {
-      string = StringLiteral(_current, StringLiteral.parseValue(_current!));
+      string = StringLiteral(_current, StringLiteral.parseValue(_current));
     } else {
       return null;
     }
@@ -342,12 +350,12 @@ class Parser {
 
     for (var type in prefixParselets.keys) {
       if (next(type)) {
-        var left = prefixParselets[type]!.parse(this, _current);
+        var left = prefixParselets[type]?.parse(this, _current);
 
         while (precedence < _nextPrecedence()) {
           _current = scanner.tokens[++_index];
 
-          if (_current!.type == TokenType.slash &&
+          if (_current.type == TokenType.slash &&
               peek()?.type == TokenType.gt) {
             // Handle `/>`
             //
@@ -357,11 +365,14 @@ class Parser {
             return left;
           }
 
-          var infix = infixParselets[_current!.type]!;
+          var infix = infixParselets[_current.type]!;
-          var newLeft = infix.parse(this, left, _current);
+          Expression? newLeft;
+          if (left != null) {
+            newLeft = infix.parse(this, left, _current);
+          }
 
           if (newLeft == null) {
-            if (_current!.type == TokenType.gt) _index--;
+            if (_current.type == TokenType.gt) _index--;
             return left;
           }
           left = newLeft;
@@ -388,11 +399,11 @@ class Parser {
 
     if (value == null) {
       errors.add(JaelError(JaelErrorSeverity.error,
-          'Missing expression in key-value pair.', colon!.span));
+          'Missing expression in key-value pair.', colon.span));
       return null;
     }
 
-    return KeyValuePair(key, colon, value as Expression?);
+    return KeyValuePair(key, colon, value as Expression);
   }
 
   NamedArgument? parseNamedArgument() {
@@ -409,7 +420,7 @@ class Parser {
 
     if (value == null) {
       errors.add(JaelError(JaelErrorSeverity.error,
-          'Missing expression in named argument.', colon!.span));
+          'Missing expression in named argument.', colon.span));
       return null;
     }
 

packages/jael/jael/lib/src/text/scanner.dart

@@ -55,7 +55,7 @@ final Map<Pattern, TokenType> _expressionPatterns = {
   '.': TokenType.dot,
   '??': TokenType.elvis,
   '?.': TokenType.elvis_dot,
-  '=': TokenType.equals,
+  //'=': TokenType.equals,
   '!': TokenType.exclamation,
   '-': TokenType.minus,
   '%': TokenType.percent,
@@ -66,14 +66,14 @@ final Map<Pattern, TokenType> _expressionPatterns = {
   '}': TokenType.rCurly,
   '(': TokenType.lParen,
   ')': TokenType.rParen,
-  '/': TokenType.slash,
+  //'/': TokenType.slash,
-  '<': TokenType.lt,
+  //'<': TokenType.lt,
   '<=': TokenType.lte,
-  '>': TokenType.gt,
+  //'>': TokenType.gt,
   '>=': TokenType.gte,
   '==': TokenType.equ,
-  '!=': TokenType.nequ,
+  //'!=': TokenType.nequ,
-  '=': TokenType.equals,
+  //'=': TokenType.equals,
   RegExp(r'-?[0-9]+(\.[0-9]+)?([Ee][0-9]+)?'): TokenType.number,
   RegExp(r'0x[A-Fa-f0-9]+'): TokenType.hex,
   _string1: TokenType.string,
@@ -82,47 +82,50 @@ final Map<Pattern, TokenType> _expressionPatterns = {
 };
 
 class _Scanner implements Scanner {
+  @override
   final List<JaelError> errors = [];
+
+  @override
   final List<Token> tokens = [];
   _ScannerState state = _ScannerState.html;
   final Queue<String?> openTags = Queue();
 
-  SpanScanner? _scanner;
+  late SpanScanner _scanner;
 
   _Scanner(String text, sourceUrl) {
     _scanner = SpanScanner(text, sourceUrl: sourceUrl);
   }
 
   void scan({bool asDSX = false}) {
-    while (!_scanner!.isDone) {
+    while (!_scanner.isDone) {
       if (state == _ScannerState.html) {
         scanHtml(asDSX);
       } else if (state == _ScannerState.freeText) {
         // Just keep parsing until we hit "</"
-        var start = _scanner!.state, end = start;
+        var start = _scanner.state, end = start;
 
-        while (!_scanner!.isDone) {
+        while (!_scanner.isDone) {
           // Skip through comments
-          if (_scanner!.scan(_htmlComment)) continue;
+          if (_scanner.scan(_htmlComment)) continue;
 
           // Break on {{ or {
-          if (_scanner!.matches(asDSX ? '{' : '{{')) {
+          if (_scanner.matches(asDSX ? '{' : '{{')) {
             state = _ScannerState.html;
             //_scanner.position--;
             break;
           }
 
-          var ch = _scanner!.readChar();
+          var ch = _scanner.readChar();
 
           if (ch == $lt) {
             // && !_scanner.isDone) {
-            if (_scanner!.matches('/')) {
+            if (_scanner.matches('/')) {
               // If we reached "</", backtrack and break into HTML
               openTags.removeFirst();
-              _scanner!.position--;
+              _scanner.position--;
               state = _ScannerState.html;
               break;
-            } else if (_scanner!.matches(_id)) {
+            } else if (_scanner.matches(_id)) {
               // Also break when we reach <foo.
               //
               // HOWEVER, that is also JavaScript. So we must
@@ -132,26 +135,26 @@ class _Scanner implements Scanner {
 
               if (!shouldBreak) {
                 // Try to see if we are closing a script tag
-                var replay = _scanner!.state;
+                var replay = _scanner.state;
                 _scanner
-                  ?..readChar()
+                  ..readChar()
                   ..scan(_whitespace);
                 //print(_scanner.emptySpan.highlight());
 
-                if (_scanner!.matches(_id)) {
+                if (_scanner.matches(_id)) {
                   //print(_scanner.lastMatch[0]);
-                  shouldBreak = _scanner!.lastMatch![0] == 'script';
+                  shouldBreak = _scanner.lastMatch?[0] == 'script';
-                  _scanner!.position--;
+                  _scanner.position--;
                 }
 
                 if (!shouldBreak) {
-                  _scanner!.state = replay;
+                  _scanner.state = replay;
                 }
               }
 
               if (shouldBreak) {
                 openTags.removeFirst();
-                _scanner!.position--;
+                _scanner.position--;
                 state = _ScannerState.html;
                 break;
               }
@@ -159,12 +162,12 @@ class _Scanner implements Scanner {
           }
 
           // Otherwise, just add to the "buffer"
-          end = _scanner!.state;
+          end = _scanner.state;
         }
 
-        var span = _scanner!.spanFrom(start, end);
+        var span = _scanner.spanFrom(start, end);
 
-        if (span.text.isNotEmpty) {
+        if (span.text?.isNotEmpty == true) {
           tokens.add(Token(TokenType.text, span, null));
         }
       }
@@ -182,35 +185,41 @@ class _Scanner implements Scanner {
 
         while (true) {
           // Scan whitespace
-          _scanner!.scan(_whitespace);
+          _scanner.scan(_whitespace);
 
           _expressionPatterns.forEach((pattern, type) {
-            if (_scanner!.matches(pattern)) {
+            if (_scanner.matches(pattern)) {
+              if (_scanner.lastSpan != null) {
                 potential
-                  .add(Token(type, _scanner!.lastSpan, _scanner!.lastMatch));
+                    .add(Token(type, _scanner.lastSpan!, _scanner.lastMatch));
+              } else {
+                // TODO: To be relooked
+              }
             }
           });
 
-          potential.sort((a, b) => b.span!.length.compareTo(a.span!.length));
+          potential.sort((a, b) => b.span.length.compareTo(a.span.length));
 
           if (potential.isEmpty) break;
 
           var token = potential.first;
           tokens.add(token);
 
-          _scanner!.scan(token.span!.text);
+          if (token.span.text != null) {
+            _scanner.scan(token.span.text!);
+          }
 
           if (token.type == TokenType.lt) {
             brackets.addFirst(token);
 
             // Try to see if we are at a tag.
-            var replay = _scanner!.state;
+            var replay = _scanner.state;
-            _scanner!.scan(_whitespace);
+            _scanner.scan(_whitespace);
 
-            if (_scanner!.matches(_id)) {
+            if (_scanner.matches(_id)) {
-              openTags.addFirst(_scanner!.lastMatch![0]);
+              openTags.addFirst(_scanner.lastMatch![0]);
             } else {
-              _scanner!.state = replay;
+              _scanner.state = replay;
             }
           } else if (token.type == TokenType.slash) {
             // Only push if we're at </foo
@@ -226,11 +235,11 @@ class _Scanner implements Scanner {
               brackets.removeFirst();
 
               // Now, ONLY continue parsing HTML if the next character is '<'.
-              var replay = _scanner!.state;
+              var replay = _scanner.state;
-              _scanner!.scan(_whitespace);
+              _scanner.scan(_whitespace);
 
-              if (!_scanner!.matches('<')) {
+              if (!_scanner.matches('<')) {
-                _scanner!.state = replay;
+                _scanner.state = replay;
                 state = _ScannerState.freeText;
                 break;
               }
@@ -241,11 +250,11 @@ class _Scanner implements Scanner {
               // We're at foo>, try to parse text?
               brackets.removeFirst();
 
-              var replay = _scanner!.state;
+              var replay = _scanner.state;
-              _scanner!.scan(_whitespace);
+              _scanner.scan(_whitespace);
 
-              if (!_scanner!.matches('<')) {
+              if (!_scanner.matches('<')) {
-                _scanner!.state = replay;
+                _scanner.state = replay;
                 state = _ScannerState.freeText;
                 break;
               }
@@ -259,7 +268,7 @@ class _Scanner implements Scanner {
           potential.clear();
         }
       }
-    } while (brackets.isNotEmpty && !_scanner!.isDone);
+    } while (brackets.isNotEmpty && !_scanner.isDone);
 
     state = _ScannerState.freeText;
   }

packages/jael/jael/pubspec.yaml

@@ -1,5 +1,5 @@
 name: jael
-version: 3.0.0
+version: 4.0.0
 description:  A simple server-side HTML templating engine for Dart. Comparable to Blade or Liquid.
 author: Tobe O <thosakwe@gmail.com>
 homepage: https://docs.angel-dart.dev/packages/front-end/jael

packages/jael/jael/test/render/dsx_test.dart

@@ -16,9 +16,9 @@ void main() {
     expect(foo.getAttribute('bar')?.value?.compute(null), 'baz');
     expect(
         foo
-            .getAttribute('yes')!
+            .getAttribute('yes')
-            .value!
+            ?.value
-            .compute(SymbolTable(values: {'no': 'maybe'})),
+            ?.compute(SymbolTable(values: {'no': 'maybe'})),
         'maybe');
   });
 

packages/jael/jael/test/render/render_test.dart

@@ -3,7 +3,7 @@ import 'package:jael/jael.dart' as jael;
 import 'package:symbol_table/symbol_table.dart';
 import 'package:test/test.dart';
 
-main() {
+void main() {
   test('attribute binding', () {
     const template = '''
 <html>

packages/jael/jael/test/text/common.dart

@@ -19,6 +19,6 @@ class _IsToken extends Matcher {
   bool matches(item, Map matchState) {
     return item is Token &&
         item.type == type &&
-        (text == null || item.span!.text == text);
+        (text == null || item.span.text == text);
   }
 }

packages/jael/jael/test/text/scan_test.dart

@@ -3,7 +3,7 @@ import 'package:jael/src/text/scanner.dart';
 import 'package:test/test.dart';
 import 'common.dart';
 
-main() {
+void main() {
   test('plain html', () {
     var tokens = scan('<img src="foo.png" />', sourceUrl: 'test.jael').tokens;
     tokens.forEach(print);