fix(mock-server): Setting content length == 0 causes the HTTP exchang…

…e to use chunked encoding #1828

consumer/junit5/src/test/java/au/com/dius/pact/consumer/junit5/HeadMethodTest.java

@@ -0,0 +1,38 @@
+package au.com.dius.pact.consumer.junit5;
+
+import au.com.dius.pact.consumer.MockServer;
+import au.com.dius.pact.consumer.dsl.PactBuilder;
+import au.com.dius.pact.core.model.V4Pact;
+import au.com.dius.pact.core.model.annotations.Pact;
+import org.apache.hc.client5.http.fluent.Request;
+import org.apache.hc.core5.http.ClassicHttpResponse;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import java.io.IOException;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+
+@ExtendWith(PactConsumerTestExt.class)
+@PactTestFor(providerName = "HeadMethodProvider")
+public class HeadMethodTest {
+  @Pact(consumer = "HeadMethodConsumer")
+  public V4Pact pact(PactBuilder builder) {
+    return builder
+      .expectsToReceiveHttpInteraction("HEAD request",
+        interaction -> interaction
+          .withRequest(request -> request.path("/v1/my/path").method("HEAD"))
+          .willRespondWith(response -> response.status(200)))
+      .toPact();
+  }
+
+  @Test
+  void testPact(MockServer mockServer) throws IOException {
+    ClassicHttpResponse httpResponse = (ClassicHttpResponse) Request.head(mockServer.getUrl() + "/v1/my/path")
+      .execute()
+      .returnResponse();
+    assertThat(httpResponse.getCode(), is(equalTo(200)));
+  }
+}

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

@@ -273,7 +273,9 @@ abstract class BaseJdkMockServer(
 
   private fun pactResponseToHttpExchange(response: IResponse, exchange: HttpExchange) {
     val headers = response.headers
-    exchange.responseHeaders.putAll(headers)
+    if (headers.isNotEmpty()) {
+      exchange.responseHeaders.putAll(headers)
+    }
     if (config.addCloseHeader) {
       exchange.responseHeaders.add("Connection", "close")
     }
@@ -283,7 +285,7 @@ abstract class BaseJdkMockServer(
       exchange.sendResponseHeaders(response.status, bytes.size.toLong())
       exchange.responseBody.write(bytes)
     } else {
-      exchange.sendResponseHeaders(response.status, 0)
+      exchange.sendResponseHeaders(response.status, -1)
     }
     exchange.close()
   }