From 8190f2b6ad9eba79408b99f4885e02c3dd0d2184 Mon Sep 17 00:00:00 2001
From: Dan Caseley <dan.caseley@morpheushq.com>
Date: Wed, 25 Aug 2021 09:42:51 +0100
Subject: [PATCH] Fixes bug where new instances of the same vendor could be
 init'd

---
 lib/src/analytics_x.dart           | 19 ++++++++++++++++++-
 test/analytics_x_test.dart         | 19 +++++++++++++++++++
 test/util/vendors_and_actions.dart |  2 ++
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/lib/src/analytics_x.dart b/lib/src/analytics_x.dart
index d4104a1..a4adf05 100644
--- a/lib/src/analytics_x.dart
+++ b/lib/src/analytics_x.dart
@@ -38,7 +38,10 @@ class AnalyticsX {
   Future<void> init(List<AnalyticsVendor> vendors, [AnalyticsError? onError]) async {
     this.onError = onError;
 
-    final newVendors = List<AnalyticsVendor>.from(vendors)..removeWhere((v) => _vendors.contains(v));
+    final uniqueVendors = _getUniqueVendorsById(vendors);
+
+    final newVendors = List<AnalyticsVendor>.from(uniqueVendors)
+      ..removeWhere((v) => _getVendorsById([v.id]).isNotEmpty);
 
     if (newVendors.isEmpty) {
       return;
@@ -83,9 +86,23 @@ class AnalyticsX {
     return _vendors.where((element) => ids.contains(element.id)).toList();
   }
 
+  List<AnalyticsVendor> _getUniqueVendorsById(List<AnalyticsVendor> vendorList) {
+    final List<String> uniqueIds = [];
+    for (final AnalyticsVendor vendor in List.from(vendorList)) {
+      if (uniqueIds.contains(vendor.id)) {
+        vendorList.remove(vendor);
+      }
+      uniqueIds.add(vendor.id);
+    }
+    return vendorList;
+  }
+
   /// Resets the list of known vendors.
   ///
   /// Doesn't perform any additional work on the [AnalyticsVendor], but permits all vendors to be passed to [init]
   /// again and have their [AnalyticsVendor.init] method invoked.
   void reset() => _vendors.clear();
+
+  /// Fetches the list of all registered (init'd) vendors
+  List<AnalyticsVendor> get allRegisteredVendors => _vendors;
 }
diff --git a/test/analytics_x_test.dart b/test/analytics_x_test.dart
index 2d43fcd..4a73148 100644
--- a/test/analytics_x_test.dart
+++ b/test/analytics_x_test.dart
@@ -67,4 +67,23 @@ void main() {
     await ax.invokeAction(FakeAction("potato"), ['NonExistentVendorId']);
     expect(fakeVendor.handleActionWasCalledXTimes, 0);
   });
+
+  test('AnalyticsX only registers one of each class of AnalyticsVendor when initialised together', () async {
+    final anotherFakeVendor = FakeVendor();
+    await ax.init([fakeVendor, anotherFakeVendor]);
+    expect(AnalyticsX().allRegisteredVendors.length, 1);
+  });
+
+  test('AnalyticsX only registers one of each class of AnalyticsVendor when initialised separately', () async {
+    final anotherFakeVendor = FakeVendor();
+    await ax.init([fakeVendor]);
+    await ax.init([anotherFakeVendor]);
+    expect(AnalyticsX().allRegisteredVendors.length, 1);
+  });
+
+  test('AnalyticsX only registers one AnalyticsVendor when two implementations are given the same ID', () async {
+    final anotherFakeVendor = FakeVendorWithSameID();
+    await ax.init([fakeVendor, anotherFakeVendor]);
+    expect(AnalyticsX().allRegisteredVendors.length, 1);
+  });
 }
diff --git a/test/util/vendors_and_actions.dart b/test/util/vendors_and_actions.dart
index 10b847e..bbad639 100644
--- a/test/util/vendors_and_actions.dart
+++ b/test/util/vendors_and_actions.dart
@@ -31,6 +31,8 @@ class FakeVendor2 extends FakeVendor {
   FakeVendor2() : super.withVendorId('Dummy2');
 }
 
+class FakeVendorWithSameID extends FakeVendor {}
+
 class BrokenFakeVendor extends FakeVendor {
   bool initWillThrow = true;
   bool handleActionWillThrow = false;