Update to Dart 3 (null safety) (Fix #2)

built_path/README.md

@@ -28,12 +28,7 @@ Path get _$diagonalLine => __$diagonalLine ??
 ```
 
 Note that for a Flutter project, you'll have to run
-`flutter packages pub run build_runner build`. Follow https://github.com/flutter/flutter/issues/13360,
-as this syntax may change in a future version of Flutter.
-
-Also note that there will be an error reported about `dart:ui` until
-https://github.com/dart-lang/build/issues/733 is resolved, but the code should
-still get generated.
+`dart run build_runner build`.
 
 The `example/` folder contains a full working example for Flutter, including 
-the `build.yaml` and generated code.
+the `build.yaml` and generated code.

built_path/example/lib/main.dart

@@ -15,13 +15,13 @@ class MyApp extends StatelessWidget {
       theme: new ThemeData(
         primarySwatch: Colors.blue,
       ),
-      home: new MyHomePage(title: 'Flutter Demo Home Page'),
+      home: const MyHomePage(title: 'Flutter Demo Home Page'),
     );
   }
 }
 
 class MyHomePage extends StatelessWidget {
-  const MyHomePage({Key key, this.title}) : super(key: key);
+  const MyHomePage({super.key, required this.title});
   final String title;
 
   @SvgPath('M20,30 Q40,5 60,30 T100,30')

built_path/example/pubspec.yaml

@@ -10,7 +10,7 @@ description: A new Flutter project.
 version: 1.0.0+1
 
 environment:
-  sdk: '>=2.0.0-dev <3.0.0'
+  sdk: '>=3.0.0 <4.0.0'
 
 dependencies:
   built_path:
@@ -22,7 +22,7 @@ dependencies:
 
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
-  cupertino_icons: ^0.1.2
+  cupertino_icons: ^1.0.5
 
 dev_dependencies:
   build_runner: ^2.1.4

built_path/lib/src/flutter_path_proxy.dart

@@ -1,12 +1,9 @@
 import 'package:path_parsing/path_parsing.dart';
 
 class FlutterPathGenProxy extends PathProxy {
-  FlutterPathGenProxy() {
-    code = new StringBuffer();
-    code.write('new Path()');
-  }
-
-  StringBuffer code;
+  StringBuffer code =
+    StringBuffer()
+      ..write('new Path()');
 
   @override
   void close() {

built_path/lib/src/path_generator.dart

@@ -8,7 +8,7 @@ import 'package:built_path_annotations/built_path_annotations.dart';
 import 'package:path_parsing/path_parsing.dart';
 import 'package:source_gen/source_gen.dart';
 
-Builder svgPathSharedPartBuilder({String formatOutput(String code)}) {
+Builder svgPathSharedPartBuilder({String formatOutput(String code)?}) {
   return new PartBuilder(
       <Generator>[new SvgPathGenerator()], '.svg_path.g.dart',
       formatOutput: formatOutput,
@@ -29,23 +29,26 @@ class SvgPathGenerator extends Generator {
   }
 
   void checkField(Element field, StringBuffer buffer, String friendlyName) {
-    DartObject annotation = _checker.firstAnnotationOf(field);
+    DartObject? annotation = _checker.firstAnnotationOf(field);
     if (annotation == null && field is FieldElement) {
-      annotation = _checker.firstAnnotationOf(field.getter);
+      final PropertyAccessorElement? getter = field.getter;
+      if (getter != null) {
+        annotation = _checker.firstAnnotationOf(getter);
+      }
     }
     if (annotation != null) {
-      buffer.writeln('Path __\$$friendlyName;');
+      buffer.writeln('Path? __\$$friendlyName;');
       buffer.writeln(
           'Path get _\$$friendlyName => __\$$friendlyName ?? (__\$$friendlyName =');
       final FlutterPathGenProxy proxy = new FlutterPathGenProxy();
 
       writeSvgPathDataToPath(
-        annotation.getField('data').toStringValue(),
+        annotation.getField('data')?.toStringValue(),
         proxy,
       );
       buffer.write(proxy);
 
-      final int fillRuleIndex =
+      final int? fillRuleIndex =
           annotation.getField('fillRule')?.getField('index')?.toIntValue();
       if (fillRuleIndex != null) {
         buffer.write(_getFillRule(fillRuleIndex));
@@ -58,12 +61,20 @@ class SvgPathGenerator extends Generator {
   FutureOr<String> generate(LibraryReader library, BuildStep buildStep) async {
     final StringBuffer buffer = new StringBuffer();
     for (Element el in library.allElements) {
+      final String? name = el.name;
+      if (name == null) {
+        continue;
+      }
       if (el is ClassElement) {
         for (FieldElement field in el.fields) {
-          checkField(field, buffer, '${el.name}_${field.name}');
+          final String? fieldName = field.name;
+          if (fieldName == null) {
+            continue;
+          }
+          checkField(field, buffer, '${name}_$fieldName');
         }
       } else {
-        checkField(el, buffer, el.name);
+        checkField(el, buffer, name);
       }
     }
     return buffer.toString();

built_path/pubspec.yaml

@@ -8,11 +8,11 @@ author: Dan Field <dfield@gmail.com>
 homepage: https://github.com/dnfield/flutter_built_path
 
 environment:
-  sdk: '>=2.0.0-dev <3.0.0'
+  sdk: '>=3.0.0 <4.0.0'
   # flutter: ">=0.5.1 <2.0.0"
 
 dependencies:
-  analyzer: ^2.7.0
+  analyzer: ^5.13.0
   build: ^2.1.1
   built_path_annotations: ^0.1.0
   # built_path_annotations:

built_path_annotations/pubspec.yaml

@@ -8,7 +8,7 @@ author: Dan Field <dfield@gmail.com>
 homepage: https://github.com/dnfield/flutter_built_path
 
 environment:
-  sdk: '>=2.12.0 <3.0.0'
+  sdk: '>=3.0.0 <4.0.0'
   # flutter: ">=0.5.1 <2.0.0"
 
 # dependencies: