Update to Dart 2.13

Dockerfile

@@ -1,4 +1,4 @@
-FROM google/dart:2.7.2 as build
+FROM google/dart:2.13.4 as build
 
 # Build Environment Vars
 ARG BUILD_ID
@@ -19,7 +19,7 @@ RUN echo "Starting the script sections" && \
 	pub get && \
 	dartfmt --set-exit-if-changed --dry-run lib bin test tool && \ 
 	pub run dependency_validator -x upgrade/ -i dart_dev && \
-	dartanalyzer bin lib test && \
+	pub run dart_dev analyze && \
 	pub run abide || echo Abide would have failed CI. && \
 	pub run test --concurrency=4 -p vm --reporter=expanded test/vm/ && \
 	tar czvf abide.pub.tgz LICENSE README.md pubspec.yaml analysis_options.yaml lib/ bin/ && \

lib/src/util.dart

@@ -13,11 +13,11 @@
 // limitations under the License.
 
 import 'dart:async';
+import 'dart:convert';
 import 'dart:io';
 
 import 'package:abide/src/constants.dart';
 import 'package:abide/src/result.dart';
-import 'package:dart2_constant/convert.dart' as convert;
 import 'package:meta/meta.dart';
 import 'package:resource/resource.dart';
 import 'package:yaml/yaml.dart';
@@ -253,8 +253,8 @@ bool checkIfStrongModeIsSet(YamlMap analysisOptions) {
 }
 
 Future<Null> writeAbideJson(AbideResult result) async {
-  String json = convert.json.encode(result);
+  String s = json.encode(result);
   final String file = '${Directory.current.path}/abide.json';
   print('Writing $file');
-  new File(file).writeAsStringSync(json);
+  new File(file).writeAsStringSync(s);
 }

pubspec.yaml

@@ -5,15 +5,14 @@ description: A command line tool to manage analysis_options.yaml and check if it
 homepage: https://github.com/Workiva/abide
 
 environment:
-  sdk: '>=1.23.0 <3.0.0'
+  sdk: ">=2.11.0 <3.0.0"
 
 executables:
   abide:
 
 dependencies:
   args:  ^1.4.4
-  dart2_constant: ^1.0.0
-  meta: ^1.2.2
+  meta: '>=1.2.2 <1.7.0'
   resource: ^2.0.0
   yaml: ^2.1.12
 

test/fixtures/dart1_project/pubspec.yaml

@@ -5,7 +5,7 @@ homepage: https://github.com/Workiva/mock_name
 publish_to: https://pub.workiva.org
 
 environment:
-  sdk: '>=1.23.0 <2.0.0'
+  sdk: ">=2.11.0 <3.0.0"
 
 dependencies:
   browser: any

test/fixtures/dart2_project/pubspec.yaml

@@ -5,4 +5,4 @@ homepage: https://github.com/Workiva/mock_name
 publish_to: https://pub.workiva.org
 
 environment:
-  sdk: '>=1.23.0 <3.0.0'
+  sdk: ">=2.11.0 <3.0.0"

upgrade/pubspec.yaml

@@ -4,7 +4,7 @@ description: A command line tool to update abide.yaml
 homepage: https://github.com/Workiva/abide
 
 environment:
-  sdk: '>=2.0.0 <3.0.0'
+  sdk: ">=2.11.0 <3.0.0"
 
 executables:
   abide_upgrade: upgrade