Mercado Pago: add idempotency key field

CHANGELOG

@@ -19,6 +19,7 @@
 * Decidir & Braintree: Scrub cryptogram and card number [almalee24] #5220
 * Naranja: Update valid number check to include luhn10 [DustinHaefele] #5217
 * Cybersource: Add apple_pay with discover. [DustinHaefele] #5213
+* MercadoPago: Add idempotency key field [yunnydang] #5229
 
 == Version 1.137.0 (August 2, 2024)
 * Unlock dependency on `rexml` to allow fixing a CVE (#5181).

lib/active_merchant/billing/gateways/mercado_pago.rb

@@ -43,6 +43,7 @@ def refund(money, authorization, options = {})
         post = {}
         authorization, original_amount = authorization.split('|')
         post[:amount] = amount(money).to_f if original_amount && original_amount.to_f > amount(money).to_f
+        add_idempotency_key(post, options)
         commit('refund', "payments/#{authorization}/refunds", post)
       end
 
@@ -105,6 +106,7 @@ def purchase_request(money, payment, options = {})
         add_net_amount(post, options)
         add_taxes(post, options)
         add_notification_url(post, options)
+        add_idempotency_key(post, options)
         add_3ds(post, options)
         post[:binary_mode] = options.fetch(:binary_mode, true) unless options[:execute_threed]
         post
@@ -212,6 +214,10 @@ def add_net_amount(post, options)
         post[:net_amount] = Float(options[:net_amount]) if options[:net_amount]
       end
 
+      def add_idempotency_key(post, options)
+        post[:idempotency_key] = options[:idempotency_key] if options[:idempotency_key]
+      end
+
       def add_notification_url(post, options)
         post[:notification_url] = options[:notification_url] if options[:notification_url]
       end
@@ -301,7 +307,11 @@ def authorization_from(response, params)
       end
 
       def post_data(parameters = {})
-        parameters.clone.tap { |p| p.delete(:device_id) }.to_json
+        params = parameters.clone.tap do |p|
+          p.delete(:device_id)
+          p.delete(:idempotency_key)
+        end
+        params.to_json
       end
 
       def inquire_path(authorization, options)
@@ -340,6 +350,7 @@ def headers(options = {})
           'Content-Type' => 'application/json'
         }
         headers['X-meli-session-id'] = options[:device_id] if options[:device_id]
+        headers['X-Idempotency-Key'] = options[:idempotency_key] if options[:idempotency_key]
         headers
       end
 

test/remote/gateways/remote_mercado_pago_test.rb

@@ -125,6 +125,12 @@ def test_successful_purchase_with_notification_url
     assert_equal 'https://www.spreedly.com/', response.params['notification_url']
   end
 
+  def test_successful_purchase_with_idempotency_key
+    response = @gateway.purchase(@amount, @credit_card, @options.merge(idempotency_key: '0d5020ed-1af6-469c-ae06-c3bec19954bb'))
+    assert_success response
+    assert_equal 'accredited', response.message
+  end
+
   def test_successful_purchase_with_payer
     response = @gateway.purchase(@amount, @credit_card, @options.merge({ payer: @payer }))
     assert_success response
@@ -157,6 +163,12 @@ def test_successful_authorize_and_capture
     assert_equal 'accredited', capture.message
   end
 
+  def test_successful_authorize_with_idempotency_key
+    response = @gateway.authorize(@amount, @credit_card, @options.merge(idempotency_key: '0d5020ed-1af6-469c-ae06-c3bec19954bb'))
+    assert_success response
+    assert_equal 'accredited', response.message
+  end
+
   def test_successful_authorize_and_capture_with_elo
     auth = @gateway.authorize(@amount, @elo_credit_card, @options)
     assert_success auth
@@ -312,6 +324,12 @@ def test_successful_verify
     assert_match %r{pending_capture}, response.message
   end
 
+  def test_successful_verify_with_idempotency_key
+    response = @gateway.verify(@credit_card, @options.merge(idempotency_key: '0d5020ed-1af6-469c-ae06-c3bec19954bb'))
+    assert_success response
+    assert_match %r{pending_capture}, response.message
+  end
+
   def test_successful_verify_with_amount
     @options[:amount] = 200
     response = @gateway.verify(@credit_card, @options)

test/unit/gateways/mercado_pago_test.rb

@@ -366,6 +366,23 @@ def test_includes_deviceid_header
     assert_success response
   end
 
+  def test_includes_idempotency_key_header
+    @options[:idempotency_key] = '12345'
+    @gateway.expects(:ssl_post).with(anything, anything, { 'Content-Type' => 'application/json' }).returns(successful_purchase_response)
+    @gateway.expects(:ssl_post).with(anything, anything, { 'Content-Type' => 'application/json', 'X-Idempotency-Key' => '12345' }).returns(successful_purchase_response)
+
+    response = @gateway.purchase(@amount, @credit_card, @options)
+    assert_success response
+  end
+
+  def test_includes_idempotency_key_header_for_refund
+    @options[:idempotency_key] = '12345'
+    @gateway.expects(:ssl_post).with(anything, anything, { 'Content-Type' => 'application/json', 'X-Idempotency-Key' => '12345' }).returns(successful_refund_response)
+
+    response = @gateway.refund(@amount, 'authorization|1.0', @options)
+    assert_success response
+  end
+
   def test_includes_additional_data
     @options[:additional_info] = { 'foo' => 'bar', 'baz' => 'quux' }
     response = stub_comms do