diff --git a/graphql_parser/lib/src/language/ast/field.dart b/graphql_parser/lib/src/language/ast/field.dart
index 3ac2c965..5aca6469 100644
--- a/graphql_parser/lib/src/language/ast/field.dart
+++ b/graphql_parser/lib/src/language/ast/field.dart
@@ -15,15 +15,17 @@ class FieldContext extends Node {
 
   @override
   FileSpan get span {
-    if (selectionSet != null)
+    if (selectionSet != null) {
       return fieldName.span.expand(selectionSet.span);
-    else if (directives.isNotEmpty)
+    } else if (directives.isNotEmpty) {
       return directives.fold<FileSpan>(
           fieldName.span, (out, d) => out.expand(d.span));
-    if (arguments.isNotEmpty)
+    }
+    if (arguments.isNotEmpty) {
       return arguments.fold<FileSpan>(
           fieldName.span, (out, a) => out.expand(a.span));
-    else
+    } else {
       return fieldName.span;
+    }
   }
 }
diff --git a/graphql_parser/lib/src/language/ast/number_value.dart b/graphql_parser/lib/src/language/ast/number_value.dart
index 8c18cfe1..d5fe010d 100644
--- a/graphql_parser/lib/src/language/ast/number_value.dart
+++ b/graphql_parser/lib/src/language/ast/number_value.dart
@@ -10,9 +10,9 @@ class NumberValueContext extends InputValueContext<num> {
 
   num get numberValue {
     var text = NUMBER.text;
-    if (!text.contains('E') && !text.contains('e'))
+    if (!text.contains('E') && !text.contains('e')) {
       return num.parse(text);
-    else {
+    } else {
       var split = text.split(text.contains('E') ? 'E' : 'e');
       var base = num.parse(split[0]);
       var exp = num.parse(split[1]);
diff --git a/graphql_parser/lib/src/language/ast/string_value.dart b/graphql_parser/lib/src/language/ast/string_value.dart
index 8789c886..da713b42 100644
--- a/graphql_parser/lib/src/language/ast/string_value.dart
+++ b/graphql_parser/lib/src/language/ast/string_value.dart
@@ -63,8 +63,9 @@ class StringValueContext extends InputValueContext<String> {
             default:
               buf.writeCharCode(next);
           }
-        } else
+        } else {
           throw SyntaxError('Unexpected "\\" in string literal.', span);
+        }
       } else {
         buf.writeCharCode(ch);
       }
diff --git a/graphql_parser/lib/src/language/parser.dart b/graphql_parser/lib/src/language/parser.dart
index 64bd6476..9ea7d33c 100644
--- a/graphql_parser/lib/src/language/parser.dart
+++ b/graphql_parser/lib/src/language/parser.dart
@@ -68,9 +68,9 @@ class Parser {
 
   OperationDefinitionContext parseOperationDefinition() {
     var selectionSet = parseSelectionSet();
-    if (selectionSet != null)
+    if (selectionSet != null) {
       return OperationDefinitionContext(null, null, null, selectionSet);
-    else {
+    } else {
       if (nextName('mutation') ||
           nextName('query') ||
           nextName('subscription')) {
@@ -79,18 +79,18 @@ class Parser {
         var variables = parseVariableDefinitions();
         var dirs = parseDirectives();
         var selectionSet = parseSelectionSet();
-        if (selectionSet != null)
-          return OperationDefinitionContext(
-              TYPE, NAME, variables, selectionSet)
+        if (selectionSet != null) {
+          return OperationDefinitionContext(TYPE, NAME, variables, selectionSet)
             ..directives.addAll(dirs);
-        else {
+        } else {
           errors.add(SyntaxError(
               'Missing selection set in fragment definition.',
               NAME?.span ?? TYPE.span));
           return null;
         }
-      } else
+      } else {
         return null;
+      }
     }
   }
 
@@ -105,11 +105,11 @@ class Parser {
           if (typeCondition != null) {
             var dirs = parseDirectives();
             var selectionSet = parseSelectionSet();
-            if (selectionSet != null)
+            if (selectionSet != null) {
               return FragmentDefinitionContext(
                   FRAGMENT, NAME, ON, typeCondition, selectionSet)
                 ..directives.addAll(dirs);
-            else {
+            } else {
               errors.add(SyntaxError(
                   'Expected selection set in fragment definition.',
                   typeCondition.span));
@@ -133,8 +133,9 @@ class Parser {
             FRAGMENT.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   FragmentSpreadContext parseFragmentSpread() {
@@ -148,8 +149,9 @@ class Parser {
         _index--;
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   InlineFragmentContext parseInlineFragment() {
@@ -184,8 +186,9 @@ class Parser {
             'Missing "on" after "..." in inline fragment.', ELLIPSIS.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   SelectionSetContext parseSelectionSet() {
@@ -201,29 +204,30 @@ class Parser {
       }
 
       eatCommas();
-      if (next(TokenType.RBRACE))
+      if (next(TokenType.RBRACE)) {
         return SelectionSetContext(LBRACE, current)
           ..selections.addAll(selections);
-      else {
+      } else {
         errors.add(SyntaxError('Missing "}" after selection set.',
             selections.isEmpty ? LBRACE.span : selections.last.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   SelectionContext parseSelection() {
     var field = parseField();
     if (field != null) return SelectionContext(field);
     var fragmentSpread = parseFragmentSpread();
-    if (fragmentSpread != null)
-      return SelectionContext(null, fragmentSpread);
+    if (fragmentSpread != null) return SelectionContext(null, fragmentSpread);
     var inlineFragment = parseInlineFragment();
-    if (inlineFragment != null)
+    if (inlineFragment != null) {
       return SelectionContext(null, null, inlineFragment);
-    else
+    } else {
       return null;
+    }
   }
 
   FieldContext parseField() {
@@ -235,8 +239,9 @@ class Parser {
       return FieldContext(fieldName, selectionSet)
         ..arguments.addAll(args ?? <ArgumentContext>[])
         ..directives.addAll(directives);
-    } else
+    } else {
       return null;
+    }
   }
 
   FieldNameContext parseFieldName() {
@@ -244,18 +249,19 @@ class Parser {
       var NAME1 = current;
       if (next(TokenType.COLON)) {
         var COLON = current;
-        if (next(TokenType.NAME))
-          return FieldNameContext(
-              null, AliasContext(NAME1, COLON, current));
-        else {
-          errors.add(SyntaxError(
-              'Missing name after colon in alias.', COLON.span));
+        if (next(TokenType.NAME)) {
+          return FieldNameContext(null, AliasContext(NAME1, COLON, current));
+        } else {
+          errors.add(
+              SyntaxError('Missing name after colon in alias.', COLON.span));
           return null;
         }
-      } else
+      } else {
         return FieldNameContext(NAME1);
-    } else
+      }
+    } else {
       return null;
+    }
   }
 
   VariableDefinitionsContext parseVariableDefinitions() {
@@ -270,16 +276,17 @@ class Parser {
         def = parseVariableDefinition();
       }
 
-      if (next(TokenType.RPAREN))
+      if (next(TokenType.RPAREN)) {
         return VariableDefinitionsContext(LPAREN, current)
           ..variableDefinitions.addAll(defs);
-      else {
+      } else {
         errors.add(SyntaxError(
             'Missing ")" after variable definitions.', LPAREN.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   VariableDefinitionContext parseVariableDefinition() {
@@ -290,20 +297,20 @@ class Parser {
         var type = parseType();
         if (type != null) {
           var defaultValue = parseDefaultValue();
-          return VariableDefinitionContext(
-              variable, COLON, type, defaultValue);
+          return VariableDefinitionContext(variable, COLON, type, defaultValue);
         } else {
-          errors.add(SyntaxError(
-              'Missing type in variable definition.', COLON.span));
+          errors.add(
+              SyntaxError('Missing type in variable definition.', COLON.span));
           return null;
         }
       } else {
-        errors.add(SyntaxError(
-            'Missing ":" in variable definition.', variable.span));
+        errors.add(
+            SyntaxError('Missing ":" in variable definition.', variable.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   TypeContext parseType() {
@@ -314,8 +321,9 @@ class Parser {
       var listType = parseListType();
       if (listType != null) {
         return TypeContext(null, listType, maybe(TokenType.EXCLAMATION));
-      } else
+      } else {
         return null;
+      }
     }
   }
 
@@ -334,8 +342,9 @@ class Parser {
         errors.add(SyntaxError('Missing type after "[".', LBRACKET.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   List<DirectiveContext> parseDirectives() {
@@ -358,10 +367,9 @@ class Parser {
         if (next(TokenType.COLON)) {
           var COLON = current;
           var val = parseInputValue();
-          if (val != null)
-            return DirectiveContext(
-                ARROBA, NAME, COLON, null, null, null, val);
-          else {
+          if (val != null) {
+            return DirectiveContext(ARROBA, NAME, COLON, null, null, null, val);
+          } else {
             errors.add(SyntaxError(
                 'Missing value or variable in directive after colon.',
                 COLON.span));
@@ -383,15 +391,16 @@ class Parser {
                 SyntaxError('Missing argument in directive.', LPAREN.span));
             return null;
           }
-        } else
-          return DirectiveContext(
-              ARROBA, NAME, null, null, null, null, null);
+        } else {
+          return DirectiveContext(ARROBA, NAME, null, null, null, null, null);
+        }
       } else {
         errors.add(SyntaxError('Missing name for directive.', ARROBA.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   List<ArgumentContext> parseArguments() {
@@ -406,15 +415,15 @@ class Parser {
         arg = parseArgument();
       }
 
-      if (next(TokenType.RPAREN))
+      if (next(TokenType.RPAREN)) {
         return out;
-      else {
-        errors
-            .add(SyntaxError('Missing ")" in argument list.', LPAREN.span));
+      } else {
+        errors.add(SyntaxError('Missing ")" in argument list.', LPAREN.span));
         return null;
       }
-    } else
+    } else {
       return [];
+    }
   }
 
   ArgumentContext parseArgument() {
@@ -423,20 +432,21 @@ class Parser {
       if (next(TokenType.COLON)) {
         var COLON = current;
         var val = parseInputValue();
-        if (val != null)
+        if (val != null) {
           return ArgumentContext(NAME, COLON, val);
-        else {
+        } else {
           errors.add(SyntaxError(
               'Missing value or variable in argument.', COLON.span));
           return null;
         }
       } else {
-        errors.add(SyntaxError(
-            'Missing colon after name in argument.', NAME.span));
+        errors.add(
+            SyntaxError('Missing colon after name in argument.', NAME.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   /// Use [parseInputValue] instead.
@@ -446,16 +456,17 @@ class Parser {
   VariableContext parseVariable() {
     if (next(TokenType.DOLLAR)) {
       var DOLLAR = current;
-      if (next(TokenType.NAME))
+      if (next(TokenType.NAME)) {
         return VariableContext(DOLLAR, current);
-      else {
+      } else {
         errors.add(SyntaxError(
             'Missing name for variable; found a lone "\$" instead.',
             DOLLAR.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   DefaultValueContext parseDefaultValue() {
@@ -465,27 +476,29 @@ class Parser {
       if (value != null) {
         return DefaultValueContext(EQUALS, value);
       } else {
-        errors
-            .add(SyntaxError('Missing value after "=" sign.', EQUALS.span));
+        errors.add(SyntaxError('Missing value after "=" sign.', EQUALS.span));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   TypeConditionContext parseTypeCondition() {
     var name = parseTypeName();
-    if (name != null)
+    if (name != null) {
       return TypeConditionContext(name);
-    else
+    } else {
       return null;
+    }
   }
 
   TypeNameContext parseTypeName() {
     if (next(TokenType.NAME)) {
       return TypeNameContext(current);
-    } else
+    } else {
       return null;
+    }
   }
 
   /// Use [parseInputValue] instead.
@@ -544,8 +557,9 @@ class Parser {
         errors.add(SyntaxError('Unterminated list literal.', lastSpan));
         return null;
       }
-    } else
+    } else {
       return null;
+    }
   }
 
   ObjectValueContext parseObjectValue() {
diff --git a/graphql_parser/lib/src/language/token.dart b/graphql_parser/lib/src/language/token.dart
index 5d12c90d..4a8498ae 100644
--- a/graphql_parser/lib/src/language/token.dart
+++ b/graphql_parser/lib/src/language/token.dart
@@ -10,9 +10,10 @@ class Token {
 
   @override
   String toString() {
-    if (span == null)
+    if (span == null) {
       return "'$text' -> $type";
-    else
+    } else {
       return "(${span.start.line}:${span.start.column}) '$text' -> $type";
+    }
   }
 }
diff --git a/graphql_parser/test/directive_test.dart b/graphql_parser/test/directive_test.dart
index 9dc30a4e..001c4ea8 100644
--- a/graphql_parser/test/directive_test.dart
+++ b/graphql_parser/test/directive_test.dart
@@ -37,8 +37,7 @@ main() {
 DirectiveContext parseDirective(String text) => parse(text).parseDirective();
 
 Matcher isDirective(String name, {Matcher valueOrVariable, Matcher argument}) =>
-    _IsDirective(name,
-        valueOrVariable: valueOrVariable, argument: argument);
+    _IsDirective(name, valueOrVariable: valueOrVariable, argument: argument);
 
 Matcher isDirectiveList(List<Matcher> directives) =>
     _IsDirectiveList(directives);
@@ -57,8 +56,9 @@ class _IsDirective extends Matcher {
       return valueOrVariable.describe(desc.add(' and '));
     } else if (argument != null) {
       return argument.describe(desc.add(' and '));
-    } else
+    } else {
       return desc;
+    }
   }
 
   @override
@@ -67,9 +67,9 @@ class _IsDirective extends Matcher {
         item is DirectiveContext ? item : parseDirective(item.toString());
     if (directive == null) return false;
     if (valueOrVariable != null) {
-      if (directive.value == null)
+      if (directive.value == null) {
         return false;
-      else {
+      } else {
         var v = directive.value;
         if (v is VariableContext) {
           return valueOrVariable.matches(v.name, matchState);
@@ -79,12 +79,14 @@ class _IsDirective extends Matcher {
         }
       }
     } else if (argument != null) {
-      if (directive.argument == null)
+      if (directive.argument == null) {
         return false;
-      else
+      } else {
         return argument.matches(directive.argument, matchState);
-    } else
+      }
+    } else {
       return true;
+    }
   }
 }
 
diff --git a/graphql_parser/test/field_test.dart b/graphql_parser/test/field_test.dart
index 30acb837..e39f3f63 100644
--- a/graphql_parser/test/field_test.dart
+++ b/graphql_parser/test/field_test.dart
@@ -88,8 +88,7 @@ Matcher isField(
         Matcher selectionSet}) =>
     _IsField(fieldName, arguments, directives, selectionSet);
 
-Matcher isFieldName(String name, {String alias}) =>
-    _IsFieldName(name, alias);
+Matcher isFieldName(String name, {String alias}) => _IsFieldName(name, alias);
 
 class _IsField extends Matcher {
   final Matcher fieldName, arguments, directives, selectionSet;
@@ -106,10 +105,12 @@ class _IsField extends Matcher {
   bool matches(item, Map matchState) {
     var field = item is FieldContext ? item : parseField(item.toString());
     if (field == null) return false;
-    if (fieldName != null && !fieldName.matches(field.fieldName, matchState))
+    if (fieldName != null && !fieldName.matches(field.fieldName, matchState)) {
       return false;
-    if (arguments != null && !arguments.matches(field.arguments, matchState))
+    }
+    if (arguments != null && !arguments.matches(field.arguments, matchState)) {
       return false;
+    }
     return true;
   }
 }
@@ -121,9 +122,10 @@ class _IsFieldName extends Matcher {
 
   @override
   Description describe(Description description) {
-    if (realName != null)
+    if (realName != null) {
       return description
           .add('is field with name "$name" and alias "$realName"');
+    }
     return description.add('is field with name "$name"');
   }
 
@@ -131,10 +133,11 @@ class _IsFieldName extends Matcher {
   bool matches(item, Map matchState) {
     var fieldName =
         item is FieldNameContext ? item : parseFieldName(item.toString());
-    if (realName != null)
+    if (realName != null) {
       return fieldName.alias?.alias == name &&
           fieldName.alias?.name == realName;
-    else
+    } else {
       return fieldName.name == name;
+    }
   }
 }
diff --git a/graphql_parser/test/fragment_spread_test.dart b/graphql_parser/test/fragment_spread_test.dart
index 6fca400d..752e1122 100644
--- a/graphql_parser/test/fragment_spread_test.dart
+++ b/graphql_parser/test/fragment_spread_test.dart
@@ -35,9 +35,10 @@ class _IsFragmentSpread extends Matcher {
 
   @override
   Description describe(Description description) {
-    if (directives != null)
+    if (directives != null) {
       return directives.describe(
           description.add('is a fragment spread named "$name" that also '));
+    }
     return description.add('is a fragment spread named "$name"');
   }
 
@@ -48,9 +49,10 @@ class _IsFragmentSpread extends Matcher {
         : parseFragmentSpread(item.toString());
     if (spread == null) return false;
     if (spread.name != name) return false;
-    if (directives != null)
+    if (directives != null) {
       return directives.matches(spread.directives, matchState);
-    else
+    } else {
       return true;
+    }
   }
 }
diff --git a/graphql_parser/test/selection_set_test.dart b/graphql_parser/test/selection_set_test.dart
index 9cf89624..cd482481 100644
--- a/graphql_parser/test/selection_set_test.dart
+++ b/graphql_parser/test/selection_set_test.dart
@@ -55,8 +55,7 @@ main() {
 SelectionSetContext parseSelectionSet(String text) =>
     parse(text).parseSelectionSet();
 
-Matcher isSelectionSet(List<Matcher> selections) =>
-    _IsSelectionSet(selections);
+Matcher isSelectionSet(List<Matcher> selections) => _IsSelectionSet(selections);
 
 class _IsSelectionSet extends Matcher {
   final List<Matcher> selections;
@@ -87,8 +86,9 @@ class _IsSelectionSet extends Matcher {
     for (int i = 0; i < set.selections.length; i++) {
       var sel = set.selections[i];
       if (!selections[i].matches(
-          sel.field ?? sel.fragmentSpread ?? sel.inlineFragment, matchState))
+          sel.field ?? sel.fragmentSpread ?? sel.inlineFragment, matchState)) {
         return false;
+      }
     }
 
     return true;
diff --git a/graphql_parser/test/type_test.dart b/graphql_parser/test/type_test.dart
index 86ad0043..5ecb0030 100644
--- a/graphql_parser/test/type_test.dart
+++ b/graphql_parser/test/type_test.dart
@@ -84,10 +84,11 @@ class _IsType extends Matcher {
 
   @override
   Description describe(Description description) {
-    if (nonNull == true)
+    if (nonNull == true) {
       return description.add('is non-null type named "$name"');
-    else
+    } else {
       return description.add('is nullable type named "$name"');
+    }
   }
 
   @override