feat: give each interaction an index when parsing the contract

lib/pact/consumer_contract/http_consumer_contract_parser.rb

@@ -13,7 +13,7 @@ def call(hash)
         Pact.configuration.error_stream.puts "WARN: This code only knows how to parse v3 pacts, attempting to parse v#{options[:pact_specification_version]} pact using v3 code."
       end
 
-      interactions = hash[:interactions].collect { |hash| Interaction.from_hash(hash, options) }
+      interactions = hash[:interactions].each_with_index.collect { |hash, index| Interaction.from_hash({ index: index }.merge(hash), options) }
       ConsumerContract.new(
         :consumer => ServiceConsumer.from_hash(hash[:consumer]),
         :provider => ServiceProvider.from_hash(hash[:provider]),

lib/pact/consumer_contract/interaction.rb

@@ -5,7 +5,7 @@ module Pact
   class Interaction
     include ActiveSupportSupport
 
-    attr_accessor :description, :request, :response, :provider_state, :provider_states, :metadata, :_id
+    attr_accessor :description, :request, :response, :provider_state, :provider_states, :metadata, :_id, :index
 
     def initialize attributes = {}
       @description = attributes[:description]
@@ -15,6 +15,7 @@ def initialize attributes = {}
       @provider_states = attributes[:provider_states]
       @metadata = attributes[:metadata]
       @_id = attributes[:_id]
+      @index = attributes[:index]
     end
 
     def self.from_hash hash, options = {}

spec/lib/pact/consumer_contract/http_consumer_contract_parser_spec.rb

@@ -11,6 +11,10 @@ module Pact
         it "correctly parses the pact" do
           expect(subject.interactions.first.response.headers['Content-Type']).to be_a(Pact::Term)
         end
+
+        it "sets the index of each interaction" do
+          expect(subject.interactions.first.index).to eq 0
+        end
       end
 
       context "with a v3 pact" do
@@ -19,6 +23,10 @@ module Pact
         it "correctly parses the pact" do
           expect(subject.interactions.first.response.body['foo']).to be_a(Pact::SomethingLike)
         end
+
+        it "sets the index of each interaction" do
+          expect(subject.interactions.first.index).to eq 0
+        end
       end
     end
   end