FIX: Correctly serialize accepted_answers (#158)

plugin.rb

@@ -689,7 +689,7 @@ SQL
 
   add_to_serializer(:user_card, :accepted_answers) do
     Post
-      .where(user: User.find_by_username('bar3'))
+      .where(user_id: object.id)
       .joins(:_custom_fields)
       .where(_custom_fields: { name: 'is_accepted_answer', value: 'true' })
       .count

spec/serializers/user_card_serializer_spec.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe UserCardSerializer do
+  let(:user) { Fabricate(:user) }
+  let(:serializer) { described_class.new(user, scope: Guardian.new, root: false) }
+  let(:json) { serializer.as_json }
+
+  it "accepted_answers serializes number of accepted answers" do
+    post = Fabricate(:post, user: user)
+    post.upsert_custom_fields(is_accepted_answer: 'true')
+    expect(serializer.as_json[:accepted_answers]).to eq(1)
+
+    post = Fabricate(:post, user: user)
+    post.upsert_custom_fields(is_accepted_answer: 'true')
+    expect(serializer.as_json[:accepted_answers]).to eq(2)
+  end
+end