Issue spockframework#1054 | Added warning to PollingConditions docume…

…ntation as wel… (spockframework#1055)

* Issue spockframework#1054 | Added warning to PollingConditions documentation as well as test that explains the issue

* Slightly rework pending feature with PollingConditions limitation

spock-core/src/main/java/org/spockframework/lang/ConditionBlock.java

@@ -24,10 +24,11 @@
  * As in expect-blocks and then-blocks, variable declarations
  * and void method invocations will not be considered conditions.
  *
- * <p>This annotation only takes effect if the closures are passed as literals,
- * and the Groovy compiler can (at compilation time) determine the target
- * type of the method invocation referencing the annotated method. If the annotated
- * method is overloaded, the closure arguments of all overloads are considered code blocks.
+ * <p>This annotation only takes effect if:
+ * - the closures are passed as literals, and the Groovy compiler can (at compilation time) determine the target
+ * type of the method invocation referencing the annotated method,
+ * - the annotated method is called on object of type known at compilation time (no "def").
+ * If the annotated method is overloaded, the closure arguments of all overloads are considered code blocks.
  */
 @Beta
 @Target(ElementType.METHOD)

spock-core/src/main/java/spock/util/concurrent/PollingConditions.java

@@ -40,6 +40,12 @@
  *   assert machine.efficiency >= 0.9
  * }
  * </pre>
+ *
+ * Warning! Avoiding assert keyword in the clojure is only possible if the conditions object type is known
+ * during compilation (no "def" on the left side):
+ * <pre>
+ *   PollingConditions conditions = new PollingConditions(timeout: 10, initialDelay: 1.5, factor: 1.25)
+ * </pre>
  */
 @Beta
 public class PollingConditions {

spock-specs/src/test/groovy/spock/util/concurrent/PollingConditionsSpec.groovy

@@ -17,10 +17,12 @@ package spock.util.concurrent
 import org.spockframework.runtime.ConditionNotSatisfiedError
 import org.spockframework.runtime.SpockTimeoutError
 import spock.lang.Issue
+import spock.lang.PendingFeature
 import spock.lang.Specification
 
 class PollingConditionsSpec extends Specification {
   PollingConditions conditions = new PollingConditions()
+  def defConditions = new PollingConditions()
 
   volatile int num = 0
   volatile String str = null
@@ -83,6 +85,32 @@ class PollingConditionsSpec extends Specification {
     }
   }
 
+  def "fails if condition is not met and assert keyword is used for def declared conditions object"() {
+    num = 50
+
+    when:
+    defConditions.eventually {
+      assert num == 42
+    }
+
+    then:
+    thrown(SpockTimeoutError)
+  }
+
+  @PendingFeature(reason = "Known limitation")
+  @Issue("https://github.com/spockframework/spock/issues/1054")
+  def "fails if condition is not met and assert keyword is not used for def declared conditions object"() {
+    num = 50
+
+    when:
+    defConditions.eventually {
+      num == 42
+    }
+
+    then:
+    thrown(SpockTimeoutError)
+  }
+
   def "can override timeout per invocation"() {
     Thread.start {
       Thread.sleep(250)