feat: maintain path portion of specified provider base URL

This allows /foo to be replayed against http://provider/bar/foo

For pact-foundation/pact-js#131

lib/pact/provider_verifier/app.rb

@@ -79,7 +79,7 @@ def configure_reverse_proxy
             preserve_host: true,
             x_forwarded_headers: false
           )
-          reverse_proxy '/', provider_base_url
+          reverse_proxy /(.*)/, "#{provider_base_url}$1"
         end
       end
 

spec/integration_with_prefix_spec.rb

@@ -0,0 +1,23 @@
+require 'json'
+
+describe "pact-provider-verifier with a prefix path in the base URL" do
+  before(:all) do
+    @pipe = IO.popen("bundle exec rackup -p 5837 spec/support/config_with_prefix.ru")
+    sleep 2
+  end
+
+  subject { `bundle exec bin/pact-provider-verifier spec/support/pacts/prefix.json -a 1 --provider-base-url http://localhost:5837/prefix -v` }
+
+  it "exits with a 0 exit code" do
+    subject
+    expect($?).to eq 0
+  end
+
+  it "the output contains a success message" do
+    expect(subject).to include "1 interaction, 0 failures"
+  end
+
+  after(:all) do
+    Process.kill 'KILL', @pipe.pid
+  end
+end

spec/support/config_with_prefix.ru

@@ -0,0 +1,3 @@
+require_relative 'provider_with_prefix'
+
+run Provider

spec/support/pacts/prefix.json

@@ -0,0 +1,26 @@
+{
+  "consumer": {
+    "name": "me"
+  },
+  "provider": {
+    "name": "they"
+  },
+  "interactions": [
+    {
+      "description": "Greeting",
+      "request": {
+        "method": "GET",
+        "path": "/foo"
+      },
+      "response": {
+        "status": 200,
+        "body": {
+          "greeting": "Hello"
+        }
+      }
+    }]
+  ,
+  "metadata": {
+    "pactSpecificationVersion": "2.0.0"
+  }
+}

spec/support/provider_with_prefix.rb

@@ -0,0 +1,10 @@
+require 'sinatra'
+require 'sinatra/base'
+require 'sinatra/json'
+require 'json'
+
+class Provider < Sinatra::Base
+  get '/prefix/foo' do
+    json :greeting => 'Hello'
+  end
+end