feat: add option to mock server to disable persistant HTTP/1.1 connections #1383 #342

Author: Ronald Holshausen

consumer/README.md

@@ -643,3 +643,13 @@ newJsonArray {
     }
  }
 ```
+
+## Dealing with persistent HTTP/1.1 connections (Keep Alive)
+
+As each test will get a new mock server, connections can not be persisted between tests. HTTP clients can cache
+connections with HTTP/1.1, and this can cause subsequent tests to fail. See [#342](https://github.com/pact-foundation/pact-jvm/issues/342)
+and [#1383](https://github.com/pact-foundation/pact-jvm/issues/1383).
+
+One option (if the HTTP client supports it, Apache HTTP Client does) is to set the system property `http.keepAlive` to `false` in 
+the test JVM. The other option is to set `pact.mockserver.addCloseHeader` to `true` to force the mock server to
+send a `Connection: close` header with every response (supported with Pact-JVM 4.2.7+).

consumer/junit/README.md

@@ -773,3 +773,13 @@ You can also just use the key instead of an expression:
 ```java
     .valueFromProviderState('userId', 'userId', 100) // will look value using userId as the key
 ```
+
+## Dealing with persistent HTTP/1.1 connections (Keep Alive)
+
+As each test will get a new mock server, connections can not be persisted between tests. HTTP clients can cache
+connections with HTTP/1.1, and this can cause subsequent tests to fail. See [#342](https://github.com/pact-foundation/pact-jvm/issues/342)
+and [#1383](https://github.com/pact-foundation/pact-jvm/issues/1383).
+
+One option (if the HTTP client supports it, Apache HTTP Client does) is to set the system property `http.keepAlive` to `false` in
+the test JVM. The other option is to set `pact.mockserver.addCloseHeader` to `true` to force the mock server to
+send a `Connection: close` header with every response (supported with Pact-JVM 4.2.7+).

consumer/junit5/README.md

@@ -204,6 +204,16 @@ To enable this:
 
 For an example, see [MultiProviderTest](https://github.com/DiUS/pact-jvm/blob/master/consumer/junit5/src/test/groovy/au/com/dius/pact/consumer/junit5/MultiProviderTest.groovy).
 
+## Dealing with persistent HTTP/1.1 connections (Keep Alive)
+
+As each test will get a new mock server, connections can not be persisted between tests. HTTP clients can cache
+connections with HTTP/1.1, and this can cause subsequent tests to fail. See [#342](https://github.com/pact-foundation/pact-jvm/issues/342)
+and [#1383](https://github.com/pact-foundation/pact-jvm/issues/1383).
+
+One option (if the HTTP client supports it, Apache HTTP Client does) is to set the system property `http.keepAlive` to `false` in
+the test JVM. The other option is to set `pact.mockserver.addCloseHeader` to `true` to force the mock server to
+send a `Connection: close` header with every response (supported with Pact-JVM 4.2.7+).
+
 # Message Pacts
 ## Consumer test for a message consumer
 For testing a consumer of messages from a message queue using JUnit 5 and Pact V4, see [AsyncMessageTest](https://github.com/pact-foundation/pact-jvm/blob/ac6a0eae0b18183f6f453eafddb89b90741ace42/consumer/junit5/src/test/java/au/com/dius/pact/consumer/junit5/AsyncMessageTest.java).

consumer/src/main/kotlin/au/com/dius/pact/consumer/MockHttpServer.kt

@@ -246,6 +246,9 @@ abstract class BaseJdkMockServer(
   private fun pactResponseToHttpExchange(response: IResponse, exchange: HttpExchange) {
     val headers = response.headers
     exchange.responseHeaders.putAll(headers)
+    if (config.addCloseHeader) {
+      exchange.responseHeaders.add("Connection", "close")
+    }
     val body = response.body
     if (body.isPresent()) {
       val bytes = body.unwrap()

consumer/src/main/kotlin/au/com/dius/pact/consumer/model/MockProviderConfig.kt

@@ -40,7 +40,8 @@ open class MockProviderConfig @JvmOverloads constructor (
   open val port: Int = 0,
   open val pactVersion: PactSpecVersion = PactSpecVersion.V3,
   open val scheme: String = HTTP,
-  open val mockServerImplementation: MockServerImplementation = MockServerImplementation.JavaHttpServer
+  open val mockServerImplementation: MockServerImplementation = MockServerImplementation.JavaHttpServer,
+  open val addCloseHeader: Boolean = false
 ) {
 
   fun url() = "$scheme://$hostname:$port"
@@ -52,12 +53,15 @@ open class MockProviderConfig @JvmOverloads constructor (
     const val HTTP = "http"
 
     @JvmStatic
+    @JvmOverloads
     fun httpConfig(
       hostname: String = LOCALHOST,
       port: Int = 0,
       pactVersion: PactSpecVersion = PactSpecVersion.V3,
-      implementation: MockServerImplementation = MockServerImplementation.JavaHttpServer
-    ) = MockProviderConfig(hostname, port, pactVersion, HTTP, implementation.merge(MockServerImplementation.JavaHttpServer))
+      implementation: MockServerImplementation = MockServerImplementation.JavaHttpServer,
+      addCloseHeader: Boolean = System.getProperty("pact.mockserver.addCloseHeader") == "true"
+    ) = MockProviderConfig(hostname, port, pactVersion, HTTP,
+      implementation.merge(MockServerImplementation.JavaHttpServer), addCloseHeader)
 
     @JvmStatic
     fun createDefault() = createDefault(LOCALHOST, PactSpecVersion.V3)
@@ -67,6 +71,7 @@ open class MockProviderConfig @JvmOverloads constructor (
 
     @JvmStatic
     fun createDefault(host: String, pactVersion: PactSpecVersion) =
-      MockProviderConfig(hostname = host, pactVersion = pactVersion)
+      MockProviderConfig(hostname = host, pactVersion = pactVersion,
+        addCloseHeader = System.getProperty("pact.mockserver.addCloseHeader") == "true")
   }
 }