Add a Changes object to the PullRequestEvent object so we can see what changed in edited PR events (#390)

* Add changes object so we can see what changed in edited PR.

* Remove unused import

* Formatting.

* Make objects const

Author: ricardoamador

lib/src/common/model/changes.dart

@@ -0,0 +1,68 @@
+import 'package:json_annotation/json_annotation.dart';
+import 'package:meta/meta.dart';
+
+part 'changes.g.dart';
+
+@immutable
+@JsonSerializable()
+class Ref {
+  const Ref(this.from);
+  final String? from;
+
+  factory Ref.fromJson(Map<String, dynamic> input) => _$RefFromJson(input);
+  Map<String, dynamic> toJson() => _$RefToJson(this);
+}
+
+@immutable
+@JsonSerializable()
+class Sha {
+  const Sha(this.from);
+  final String? from;
+
+  factory Sha.fromJson(Map<String, dynamic> input) => _$ShaFromJson(input);
+  Map<String, dynamic> toJson() => _$ShaToJson(this);
+}
+
+@immutable
+@JsonSerializable()
+class Base {
+  const Base(this.ref, this.sha);
+  final Ref? ref;
+  final Sha? sha;
+
+  factory Base.fromJson(Map<String, dynamic> input) => _$BaseFromJson(input);
+  Map<String, dynamic> toJson() => _$BaseToJson(this);
+}
+
+@immutable
+@JsonSerializable()
+class Body {
+  const Body(this.from);
+  final String? from;
+
+  factory Body.fromJson(Map<String, dynamic> input) => _$BodyFromJson(input);
+  Map<String, dynamic> toJson() => _$BodyToJson(this);
+}
+
+@immutable
+@JsonSerializable()
+class Title {
+  const Title({this.from});
+  final String? from;
+
+  factory Title.fromJson(Map<String, dynamic> input) => _$TitleFromJson(input);
+  Map<String, dynamic> toJson() => _$TitleToJson(this);
+}
+
+@immutable
+@JsonSerializable()
+class Changes {
+  const Changes(this.base, this.body, this.title);
+  final Base? base;
+  final Body? body;
+  final Title? title;
+
+  factory Changes.fromJson(Map<String, dynamic> input) =>
+      _$ChangesFromJson(input);
+  Map<String, dynamic> toJson() => _$ChangesToJson(this);
+}

lib/src/common/model/changes.g.dart

@@ -1,8 +1,11 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
+
 import 'package:json_annotation/json_annotation.dart';
+
 import '../common.dart';
+import '../common/model/changes.dart';
 
 part 'hooks.g.dart';
 
@@ -203,12 +206,14 @@ class PullRequestEvent extends HookEvent {
     this.pullRequest,
     this.sender,
     this.repository,
+    this.changes,
   });
   String? action;
   int? number;
   PullRequest? pullRequest;
   User? sender;
   Repository? repository;
+  Changes? changes;
 
   factory PullRequestEvent.fromJson(Map<String, dynamic> input) =>
       _$PullRequestEventFromJson(input);

lib/src/server/hooks.dart

@@ -57,4 +57,29 @@ void main() {
       expect(sender.htmlUrl, "https://github.com/Codertocat");
     });
   });
+
+  group('EditedPullRequest', () {
+    test('deserialize with body edit', () {
+      final pullRequestEditedEvent = PullRequestEvent.fromJson(
+          jsonDecode(prBodyEditedEvent) as Map<String, dynamic>);
+      final changes = pullRequestEditedEvent.changes;
+      expect(changes, isNotNull);
+      expect(changes!.body!.from, isNotNull);
+      assert(changes.body!.from ==
+          '**This should not land until https://github.com/flutter/buildroot/pull/790');
+    });
+
+    test('deserialize with base edit', () {
+      final pullRequestEditedEvent = PullRequestEvent.fromJson(
+          jsonDecode(prBaseEditedEvent) as Map<String, dynamic>);
+      final changes = pullRequestEditedEvent.changes;
+      expect(changes, isNotNull);
+      expect(changes!.body, isNull);
+      expect(changes.base, isNotNull);
+      expect(changes.base!.ref, isNotNull);
+      assert(changes.base!.ref!.from == 'main');
+      assert(changes.base!.sha!.from ==
+          'b3af5d64d3e6e2110b07d71909fc432537339659');
+    });
+  });
 }