DigixGlobal#70 tests for watched_transaction_resolver

app/graphql/resolvers/watched_transaction_resolver.rb

@@ -10,9 +10,9 @@ class WatchedTransactionResolver < Resolvers::Base
 
     def resolve(txhash:)
       unless (tx = WatchingTransaction.find_by(txhash: txhash))
-        nil
+        return nil
       end
-      WatchingTransaction.where(group_id: tx.group_id).last
+      WatchingTransaction.where(group_id: tx.group_id).order('created_at ASC').last
     end
 
     def self.authorized?(object, context)

test/graphql/watched_transaction_query_test.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class UserQueryTest < ActiveSupport::TestCase
+  QUERY = <<~EOS
+    query($txhash: String!) {
+      watchedTransaction(txhash: $txhash) {
+        id
+      }
+    }
+  EOS
+
+  test 'watched transaction should work' do
+    first_transaction = create(:watching_transaction)
+    sleep 1
+    last_transaction = create(:watching_transaction, group_id: first_transaction.group_id, user: first_transaction.user)
+    result = DaoServerSchema.execute(
+      QUERY,
+      context: { current_user: first_transaction.user },
+      variables: { txhash: first_transaction.txhash }
+    )
+
+    assert_nil result['errors'],
+               'should work and have no errors'
+
+    data = result['data']['watchedTransaction']
+
+    assert_not_empty data,
+                     'watchedTransaction type should work'
+    assert_equal last_transaction.id, data['id'],
+                 'should return last transaction from group'
+
+    empty_result = DaoServerSchema.execute(
+      QUERY,
+      context: { current_user: first_transaction.user },
+      variables: { txhash: 'NON_EXISTENT_TXHASH' }
+    )
+
+    assert_nil empty_result['data']['watchedTransaction'],
+               'data should be empty on invalid txhash'
+  end
+end