#20 Create example with field of optional dependency type

test-module/src/main/java/ch/jalu/testmodule/ClassWithField.java

@@ -0,0 +1,19 @@
+package ch.jalu.testmodule;
+
+import javax.validation.Validator;
+
+/**
+ * Sample class with a field from a non-provided dependency.
+ */
+public class ClassWithField {
+
+    private Validator validator;
+
+    public ClassWithField() {
+    }
+
+    public String getName(ClassWithMethodParam cwmp) {
+        return cwmp.getName();
+    }
+
+}

test-module/src/main/java/ch/jalu/testmodule/Main.java

@@ -16,11 +16,19 @@ public static void main(String... args) {
             // all good
         }
 
+        // Create injector
         Injector injector = new InjectorBuilder().addDefaultHandlers("ch.jalu.testmodule").create();
+
+        // Instantiate class with method param
         ClassWithMethodParam classWithMethodParam = injector.getSingleton(ClassWithMethodParam.class);
         if (!"one service".equals(classWithMethodParam.getName())) {
             throw new IllegalStateException("ClassWithMethodParam#getName was not as expected");
         }
 
+        // Instantiate class with optional field (via fallback instantiation to trigger field injection scan)
+        ClassWithField classWithField = injector.getSingleton(ClassWithField.class);
+        if (!"one service".equals(classWithField.getName(classWithMethodParam))) {
+            throw new IllegalStateException("ClassWithField#getName was not as expected");
+        }
     }
 }