[plugin_platform_interface] Migrate to null safety (flutter#3115)

Author: Emmanuel Garcia

.cirrus.yml

@@ -37,7 +37,7 @@ task:
         # https://github.com/flutter/flutter/issues/42864
         - if [[ "$CHANNEL" -eq "stable" ]]; then find . | grep _web$ | xargs rm -rf; fi
         - flutter channel $CHANNEL
-        - ./script/incremental_build.sh test
+        - ./script/incremental_build.sh test --enable-experiment=non-nullable
     - name: analyze
       script: ./script/incremental_build.sh analyze
     - name: build_all_plugins_apk
@@ -87,13 +87,13 @@ task:
         - echo "$CIRRUS_COMMIT_MESSAGE" > /tmp/cirrus_commit_message.txt
         - export CIRRUS_CHANGE_MESSAGE=""
         - export CIRRUS_COMMIT_MESSAGE=""
-        - ./script/incremental_build.sh build-examples --apk
+        - ./script/incremental_build.sh build-examples --apk --enable-experiment=non-nullable
         - ./script/incremental_build.sh java-test  # must come after apk build
         - if [[ $GCLOUD_FIREBASE_TESTLAB_KEY == ENCRYPTED* ]]; then
         -   echo "This user does not have permission to run Firebase Test Lab tests."
         - else
         -   echo $GCLOUD_FIREBASE_TESTLAB_KEY > ${HOME}/gcloud-service-key.json
-        -   ./script/incremental_build.sh firebase-test-lab --device model=flame,version=29 --device model=starqlteue,version=26
+        -   ./script/incremental_build.sh firebase-test-lab --device model=flame,version=29 --device model=starqlteue,version=26 --enable-experiment=non-nullable
         - fi
         - export CIRRUS_CHANGE_MESSAGE=`cat /tmp/cirrus_change_message.txt`
         - export CIRRUS_COMMIT_MESSAGE=`cat /tmp/cirrus_commit_message.txt`
@@ -177,8 +177,8 @@ task:
         # https://github.com/flutter/flutter/issues/42864
         - if [[ "$CHANNEL" -eq "stable" ]]; then find . | grep _web$ | xargs rm -rf; fi
         - flutter channel $CHANNEL
-        - ./script/incremental_build.sh build-examples --ipa
-        - ./script/incremental_build.sh drive-examples
+        - ./script/incremental_build.sh build-examples --ipa --enable-experiment=non-nullable
+        - ./script/incremental_build.sh drive-examples --enable-experiment=non-nullable
 task:
   # don't run on release tags since it creates O(n^2) tasks where n is the number of plugins
   only_if: $CIRRUS_TAG == ''

analysis_options.yaml

@@ -1,5 +1,7 @@
 include: package:pedantic/analysis_options.1.8.0.yaml
 analyzer:
+  enable-experiment:
+    - non-nullable
   exclude:
     # Ignore generated files
     - '**/*.g.dart'

packages/plugin_platform_interface/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.1.0-nullsafety
+
+* Migrate to null safety.
+
 ## 1.0.3
 
 * Fix homepage in `pubspec.yaml`.

packages/plugin_platform_interface/lib/plugin_platform_interface.dart

@@ -41,7 +41,7 @@ import 'package:meta/meta.dart';
 /// [MockPlatformInterfaceMixin] for a sample of using Mockito to mock a platform interface.
 abstract class PlatformInterface {
   /// Pass a private, class-specific `const Object()` as the `token`.
-  PlatformInterface({@required Object token}) : _instanceToken = token;
+  PlatformInterface({required Object token}) : _instanceToken = token;
 
   final Object _instanceToken;
 

packages/plugin_platform_interface/pubspec.yaml

@@ -12,17 +12,20 @@ description: Reusable base class for Flutter plugin platform interfaces.
 # be done when absolutely necessary and after the ecosystem has already migrated to 1.X.Y version
 # that is forward compatible with 2.0.0 (ideally the ecosystem have migrated to depend on:
 # `plugin_platform_interface: >=1.X.Y <3.0.0`).
-version: 1.0.3
+version: 1.1.0-nullsafety
 
 repository: https://github.com/flutter/plugins/tree/master/packages/plugin_platform_interface
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: '>=2.10.0-56.0.dev <3.0.0'
+
+# Don't publish this package until null safety is stable or the package is in the allow list.
+publish_to: none
 
 dependencies:
-  meta: ^1.0.0
+  meta: ^1.3.0-nullsafety.3
 
 dev_dependencies:
   mockito: ^4.1.1
-  test: ^1.9.4
-  pedantic: ^1.8.0
+  test: ^1.10.0-nullsafety.1
+  pedantic: ^1.10.0-nullsafety.1

packages/plugin_platform_interface/test/plugin_platform_interface_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// TODO(egarciad): Remove once Mockito is migrated to null safety.
+// @dart = 2.9
 import 'package:mockito/mockito.dart';
 import 'package:test/test.dart';