feat([PoC]): Contract for sequence of messages

.ruby-version

@@ -1 +1 @@
-3.0.4
+3.0.3

Gemfile

@@ -8,7 +8,9 @@ group :development, :test do
 
   gem 'pact'
 
-  gem 'pact-message'
+  gem 'pact-message', git: 'https://github.com/Mifrill/pact-message-ruby', branch: 'feature/messages'
 
   gem 'rake'
-end
+
+  gem 'byebug'
+end

Gemfile.lock

@@ -1,7 +1,18 @@
+GIT
+  remote: https://github.com/Mifrill/pact-message-ruby
+  revision: 1b55bec934ed37896f4e8860b63ae1eed0070589
+  branch: feature/messages
+  specs:
+    pact-message (0.11.1)
+      pact-mock_service (~> 3.1)
+      pact-support (~> 1.8)
+      thor (>= 0.20, < 2.0)
+
 GEM
   remote: https://rubygems.org/
   specs:
     awesome_print (1.9.2)
+    byebug (11.1.3)
     coderay (1.1.3)
     diff-lcs (1.5.0)
     expgen (0.1.1)
@@ -18,10 +29,6 @@ GEM
       term-ansicolor (~> 1.0)
       thor (>= 0.20, < 2.0)
       webrick (~> 1.3)
-    pact-message (0.11.1)
-      pact-mock_service (~> 3.1)
-      pact-support (~> 1.8)
-      thor (>= 0.20, < 2.0)
     pact-mock_service (3.10.0)
       filelock (~> 1.1)
       find_a_port (~> 1.0.1)
@@ -71,11 +78,12 @@ PLATFORMS
   x86_64-darwin-21
 
 DEPENDENCIES
+  byebug
   pact
-  pact-message
+  pact-message!
   pry
   rake
   rspec
 
 BUNDLED WITH
-   2.2.33
+   2.3.26

app/consumers/test_message_consumer.rb

@@ -1,9 +1,5 @@
 class TestMessageConsumer
-
   def consume_message(message)
-    puts "Message consumed"
-    puts message.to_json
     message
   end
-
-  end
+end

app/producers/test_message_producer.rb

@@ -1,12 +1,13 @@
 class TestMessageProducer
-
-def publish_message()
-  message = {
-    "email": "[email protected]",
-    "title": "Miss",
-    "first_name": "Jane",
-    "surname": "Doe"   
-  }
+  def publish_message
+    [
+      {
+        "first_name": "John",
+        "last_name": "Doe"
+      },
+      {
+        "hello": "world"
+      }
+    ]
+  end
 end
-
-end

log/pact.log

@@ -0,0 +1,9 @@
+# Logfile created on 2023-02-09 19:42:49 +0000 by logger.rb/v1.4.3
+I, [2023-02-09T19:42:49.857092 #48830]  INFO -- : Running example 'Verifying a pact between Test Message Consumer and Test Message Producer Given Class1 updated has matching content'
+I, [2023-02-09T19:42:49.857543 #48830]  INFO -- : Sending POST request to path: "/" with headers: {"CONTENT_TYPE"=>"application/json"}, see debug logs for body
+D, [2023-02-09T19:42:49.857570 #48830] DEBUG -- : body :{"description":"updated","providerStates":[{"name":"Class1","params":{}}],"metadata":null}
+I, [2023-02-09T19:45:49.705091 #53882]  INFO -- : Running example 'Verifying a pact between Test Message Consumer and Test Message Producer Given Class1 created;updated has matching content'
+I, [2023-02-09T19:45:49.705755 #53882]  INFO -- : Sending POST request to path: "/" with headers: {"CONTENT_TYPE"=>"application/json"}, see debug logs for body
+D, [2023-02-09T19:45:49.705791 #53882] DEBUG -- : body :{"description":"created;updated","providerStates":[{"name":"Class1","params":{}}],"metadata":null}
+I, [2023-02-09T19:45:49.711473 #53882]  INFO -- : Received response with status: 200, headers: {"Content-Type"=>"application/json"}, see debug logs for body
+D, [2023-02-09T19:45:49.711504 #53882] DEBUG -- : body: {"contents":[{"first_name":"John","last_name":"Doe"},{"hello":"world"}]}

reports/pacts/help.md

@@ -0,0 +1,25 @@
+# For assistance debugging failures
+
+* The pact files have been stored locally in the following temp directory:
+    /Users/alex.strizhak/Downloads/pact-ruby-demo/tmp/pacts
+
+* The requests and responses are logged in the following log file:
+    /Users/alex.strizhak/Downloads/pact-ruby-demo/log/pact.log
+
+* Add BACKTRACE=true to the `rake pact:verify` command to see the full backtrace
+
+* If the diff output is confusing, try using another diff formatter.
+  The options are :unix, :embedded and :list
+
+    Pact.configure do | config |
+      config.diff_formatter = :embedded
+    end
+
+  See https://github.com/pact-foundation/pact-ruby/blob/master/documentation/configuration.md#diff_formatter for examples and more information.
+
+* Check out https://github.com/pact-foundation/pact-ruby/wiki/Troubleshooting
+
+* Ask a question on stackoverflow and tag it `pact-ruby`
+
+
+Tried to retrieve diff with previous pact, but received error Pact::Hal::RelationNotFoundError Could not find relation 'pb:diff-previous-distinct' in resource at spec/pacts/test_message_consumer-test_message_producer.json.

spec/consumer_spec.rb

@@ -1,52 +1,39 @@
 require 'pact/message/consumer/rspec'
 require 'support/pact_spec_helper.rb'
-require_relative '../app/consumers/test_message_consumer.rb'
-
-describe TestMessageConsumer, pact: true do
 
-  subject(:consumer) {TestMessageConsumer.new}
-
-  # Notice that the expected message payload has fields which are different to that of the actual producer.
-  # The TestMessageProducer actually sends a message with an additional 'title' field and a renamed 'surname' field.
-  # See app/producers/test_message_producer.rb.
+require_relative '../app/consumers/test_message_consumer.rb'
 
-  expected_payload = {
-    "email": "[email protected]",
-    "first_name": "Jane",
-    "last_name": "Doe"   
+describe TestMessageConsumer do
+  let(:expected_payload_1) {
+    {
+      "first_name": "John",
+      "last_name": "Doe"
+    }
   }
-
-  # Notice the new pact: :message decorator/metadata 
+  let(:expected_payload_2) {
+    {
+      "hello": "world"
+    }
+  }
+  let(:consumer) { described_class.new }
 
   describe "Test Message Consumer", pact: :message do
-    before do
-
-      # Here we are calling test_message_producer, which is mocking the actual TestMessageProducer defined in app/producers/test_message_producer.rb.
-      # In pact-message we use mocked providers in consumer side tests. These are defined in a similar way to mocked APIs/service providers in standard HTTP CDCT.
-      # See spec/support/pact_spec_helper.rb.
-
-      test_message_producer.given("A customer is created")
-      .is_expected_to_send("a customer created message")
-      # .with_metadata()
-      .with_content(expected_payload)
-
-      test_message_producer.send_message_string do | content_string |
-        @message = consumer.consume_message(content_string)
+    it "generates contract" do
+      test_message_producer
+        .given("Class1")
+        .is_expected_to_send("created")
+        .with_content(expected_payload_1)
+      test_message_producer.send_message_string do |content_string|
+        expect(consumer.consume_message(content_string)).to eq(expected_payload_1.to_json)
       end
 
+      test_message_producer
+        .given("Class2")
+        .is_expected_to_send("updated")
+        .with_content(expected_payload_2)
+      test_message_producer.send_message_string do |content_string|
+        expect(consumer.consume_message(content_string)).to eq(expected_payload_2.to_json)
+      end
     end
-
-    # This test is a bit redundant, it's essentially marking our own homework and will always pass.
-    # However IRL the consumer would probably be doing something more complex which we could assert on.
-    # See spec/pacts/test_message_consumer-test_message_producer.json for the generated contract file.
-    # Note that this contract does not match what the producer outputs in app/producers/test_message_producer.rb..
-    # If we were to run producer side verification on this contract, it should fail. 
-    # This failure would indicate a mismatch between the consumers expectations of the message format and what the producer actually sends.
-
-    it "Successfully consumes the message and creates a pact contract file" do
-      expect(@message).to eq(expected_payload.to_json)
-    end
-
   end
-
-end
+end

spec/pacts/test_message_consumer-test_message_producer.json

@@ -7,19 +7,28 @@
   },
   "messages": [
     {
-      "description": "a customer created message",
+      "description": "created;updated",
       "providerStates": [
         {
-          "name": "A customer is created",
+          "name": "Class1",
           "params": {
           }
+        },
+        {
+          "name": "Class2",
+          "params": {
+          }
+        }
+      ],
+      "contents": [
+        {
+          "first_name": "John",
+          "last_name": "Doe"
+        },
+        {
+          "hello": "world"
         }
       ],
-      "contents": {
-        "email": "[email protected]",
-        "first_name": "Jane",
-        "last_name": "Doe"
-      },
       "matchingRules": {
       }
     }

spec/service_consumers/pact_helper.rb

@@ -9,36 +9,35 @@
 require 'pact/message'
 
 Pact.message_provider "Test Message Provider" do
-
-  # Explictly creates an instance of the producer. 
-  # This might be different to how we create instances of rails/rack APIs in HTTP Pact. 
-  Producer = TestMessageProducer.new
-
-  # This matches the usage in HTTP Pact. 
+  # This matches the usage in HTTP Pact.
   honours_pact_with "Test Message Consumer" do
     pact_uri "spec/pacts/test_message_consumer-test_message_producer.json"
   end
 
-  # Create a hash of all the messages the producer needs to publish to meet the preconditions of the contract files it is referenced in.
-  # This is the recommended approach in the pact-message-ruby documentation. See https://github.com/pact-foundation/pact-message-ruby
-  MESSAGES = {
-    "a customer created message" => lambda { Producer.publish_message }
-  }
-
   # Builder which populates the hash.
   # Calls the lambda above, which calls the Producer.publish_message method.
   # See app/producers/test_message_producer.rb.
-  # The producer publishes a message (json). 
-  # The message is used in the dynamically generated RSpec tests to verify the contract provided by the consumer. 
+  # The producer publishes a message (json).
+  # The message is used in the dynamically generated RSpec tests to verify the contract provided by the consumer.
   builder do |message_description|
-    MESSAGES[message_description].call
+    # Explictly creates an instance of the producer.
+    # This might be different to how we create instances of rails/rack APIs in HTTP Pact.
+    producer = TestMessageProducer.new
+
+    # Create a hash of all the messages the producer needs to publish to meet the preconditions of the contract files it is referenced in.
+    # This is the recommended approach in the pact-message-ruby documentation. See https://github.com/pact-foundation/pact-message-ruby
+    messages = {
+      "created;updated" => lambda { producer.publish_message },
+    }
+
+    messages[message_description].call
   end
 
-  #Execute the following to run the provider side verification on the contract files in spec/pacts: 
+  #Execute the following to run the provider side verification on the contract files in spec/pacts:
   # bundle exec rake pact:verify
   # The pact verification tool will do the following:
   # 1. Read the contract files (pact files) in spec/pacts.
   # 2. Setup the required pre-requiste test state (provider states) referenced in the contract files.
   # 3. Dynamically generate and execute RSpec tests based on the content of the contract files.
 
-end
+end

spec/service_consumers/provider_states_for_test_message_consumer.rb

@@ -1,10 +1,13 @@
 Pact.provider_states_for "Test Message Consumer" do
 
-  provider_state "A customer is created" do
+  provider_state "Class1" do
     set_up do
-      # no_op
-      # Pre-requiste test setup code to create this state would go here
+      # Pre-requests test setup code to create this state would go here
     end
   end
 
-end
+  provider_state "Class2" do
+    set_up do
+    end
+  end
+end