dart sdk null safety migration

Author: lohanidamodar

templates/dart/lib/client.dart.twig

@@ -3,13 +3,13 @@ part of {{ language.params.packageName }};
 class Client {
     String endPoint;
     String type = 'unknown';
-    Map<String, String> headers;
-    Map<String, String> config;
+    Map<String, String>? headers;
+    late Map<String, String> config;
     bool selfSigned;
     bool initialized = false;
     Dio http;
 
-    Client({this.endPoint = '{{spec.endpoint}}', this.selfSigned = false, Dio http}) : this.http = http ?? Dio() {
+    Client({this.endPoint = '{{spec.endpoint}}', this.selfSigned = false, Dio? http}) : this.http = http ?? Dio() {
 
         this.headers = {
             'content-type': 'application/json',
@@ -48,19 +48,19 @@ class Client {
     }
 
     Client addHeader(String key, String value) {
-        headers[key] = value;
+        headers![key] = value;
 
         return this;
     }
 
     Future init() async {
         if(!initialized) {
           this.http.options.baseUrl = this.endPoint;
-          this.http.options.validateStatus = (status) => status < 400;
+          this.http.options.validateStatus = (status) => status! < 400;
         }
     }
 
-    Future<Response> call(HttpMethod method, {String path = '', Map<String, String> headers = const {}, Map<String, dynamic> params = const {}, ResponseType responseType}) async {
+    Future<Response> call(HttpMethod method, {String path = '', Map<String, String> headers = const {}, Map<String, dynamic> params = const {}, ResponseType? responseType}) async {
         if(selfSigned) {
             // Allow self signed requests
             (http.httpClientAdapter as DefaultHttpClientAdapter).onHttpClientCreate = (HttpClient client) {
@@ -73,7 +73,7 @@ class Client {
 
         // Origin is hardcoded for testing
         Options options = Options(
-            headers: {...this.headers, ...headers},
+            headers: {...this.headers!, ...headers},
             method: method.name(),
             responseType: responseType
         );
@@ -96,9 +96,9 @@ class Client {
           if(e.response == null) {
             throw {{spec.title | caseUcfirst}}Exception(e.message);
           }
-          throw {{spec.title | caseUcfirst}}Exception(e.response.data['message'],e.response.data['code'], e.response.data);
+          throw {{spec.title | caseUcfirst}}Exception(e.response!.data['message'],e.response!.data['code'], e.response!.data);
         } catch(e) {
-          throw {{spec.title | caseUcfirst}}Exception(e.message);
+          throw {{spec.title | caseUcfirst}}Exception(e.toString());
         }
     }
 }

templates/dart/lib/exception.dart.twig

@@ -1,8 +1,8 @@
 part of {{ language.params.packageName }};
 
 class {{spec.title | caseUcfirst}}Exception implements Exception {
-  final String message;
-  final int code;
+  final String? message;
+  final int? code;
   final dynamic response;
 
   {{spec.title | caseUcfirst}}Exception([this.message = "", this.code, this.response]);

templates/dart/lib/services/service.dart.twig

@@ -1,8 +1,8 @@
 part of {{ language.params.packageName }};
 
 {% macro parameter(parameter) %}
-{% if parameter.name == 'orderType' %}{% if parameter.required %}@required {% endif %}{{ 'OrderType orderType = OrderType.asc' }}{% else %}
-{% if parameter.required %}@required {% endif %}{{ parameter.type | typeName }} {{ parameter.name | caseCamel }}{{ parameter | escapeDollarSign | paramDefault }}{% endif %}
+{% if parameter.name == 'orderType' %}{% if parameter.required %}required {% endif %}{{ 'OrderType orderType = OrderType.asc' }}{% else %}
+{% if parameter.required %}required {% endif %}{{ parameter.type | typeName }} {{ parameter.name | caseCamel }}{{ parameter | escapeDollarSign | paramDefault }}{% endif %}
 {% endmacro %}
 {% macro method_parameters(parameters) %}
 {% if parameters.all|length > 0 %}{{ '{' }}{% for parameter in parameters.all %}{{ _self.parameter(parameter) }}{% if not loop.last %}, {% endif %}{% endfor %}{{ '}' }}{% endif %}

templates/dart/pubspec.yaml.twig

@@ -6,10 +6,10 @@ repository: https://github.com/{{sdk.gitUserName}}/{{sdk.gitRepoName}}
 issue_tracker: https://github.com/appwrite/sdk-generator/issues
 documentation: {{ spec.contactURL }}
 environment:
-  sdk: '>=2.6.0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
 dependencies:
-  dio: ^3.0.10
-  meta: ^1.1.8
+  dio: ^4.0.0-beta4
+  meta: ^1.3.0
 
 dev_dependencies:
-  test:
+  test: ^1.16.5