Fixed HostPortWaitStrategy throws NumberFormatException when port is exposed but not mapped (#640)

* Fixed `HostPortWaitStrategy` throws `NumberFormatException`
when port is exposed but not mapped

* updated exposed port tests are suggested in code review

Author: barrycommins

CHANGELOG.md

@@ -4,6 +4,7 @@ All notable changes to this project will be documented in this file.
 ## UNRELEASED
 
 ### Fixed
+- Fixed `HostPortWaitStrategy` throws `NumberFormatException` when port is exposed but not mapped [\#640](https://github.com/testcontainers/testcontainers-java/issues/640))
 
 ### Changed
 

core/src/main/java/org/testcontainers/containers/ContainerState.java

@@ -11,6 +11,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 public interface ContainerState {
@@ -127,6 +128,7 @@ default List<Integer> getBoundPortNumbers() {
             .map(PortBinding::parse)
             .map(PortBinding::getBinding)
             .map(Ports.Binding::getHostPortSpec)
+            .filter(Objects::nonNull)
             .map(Integer::valueOf)
             .collect(Collectors.toList());
     }

core/src/test/resources/v2-compose-test.yml

@@ -1,4 +1,6 @@
 version: '2'
 services:
   redis:
-    image: redis
+    image: redis
+    ports:
+      - 6379