Informative error message when reequesting a list of evnets that cont…

…ains null (closes #184)
bThink-BGU · Jul 12, 2022 · f15b469 · f15b469
1 parent c3efaee
commit f15b469
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Showing 2 changed files with 10 additions and 4 deletions.
diff --git a/README.md b/README.md
@@ -62,6 +62,7 @@ If you use BPjs in an academic work, please consider citing it as:
 * :arrow_up: Improved warrping of Java objects as they come to JavaScript: Java strings are now treated as native JS strings, so using the `===` operator works as expected. ([#104](https://github.com/bThink-BGU/BPjs/issues/104)).
 * :bug: Verification stops on ECMAScript errors ([#49](https://github.com/bThink-BGU/BPjs/issues/49)).
 * :bug: Improved error reporting when trying to sync outside of a b-thread ([#174](https://github.com/bThink-BGU/BPjs/issues/174)).
+* :arrow_up: Informative error message when requesting a list of events and one of the events is `null` ([#184](https://github.com/bThink-BGU/BPjs/issues/184)).
 
 
 ### 2022-02 (Including the 1st BP Day Hackathon)

diff --git a/src/main/java/il/ac/bgu/cs/bp/bpjs/execution/jsproxy/BProgramJsProxy.java b/src/main/java/il/ac/bgu/cs/bp/bpjs/execution/jsproxy/BProgramJsProxy.java
@@ -7,6 +7,7 @@
 import il.ac.bgu.cs.bp.bpjs.model.eventsets.EventSet;
 import il.ac.bgu.cs.bp.bpjs.model.eventsets.EventSets;
 import il.ac.bgu.cs.bp.bpjs.model.eventsets.JsEventSet;
+import java.util.List;
 import org.mozilla.javascript.*;
 
 import java.util.Map;
@@ -250,9 +251,13 @@ void synchronizationPoint(NativeObject jsRWB, Boolean hot, Object data) {
             try {
                 if (req instanceof NativeArray) {
                     NativeArray arr = (NativeArray) req;
-                    stmt = stmt.request(arr.getIndexIds().stream()
-                            .map(i -> (BEvent) arr.get(i))
-                            .collect(toList()));
+                    final List<BEvent> requestedEvents = arr.getIndexIds().stream()
+                        .map(i -> (BEvent) arr.get(i))
+                        .collect(toList());
+                    if ( requestedEvents.contains(null) ) {
+                        throw new RuntimeException("Cannot request a null event. B-thread name: "+ CURRENT_BTHREAD.get().snapshot.getName());
+                    }
+                    stmt = stmt.request(requestedEvents);
                 } else {
                     stmt = stmt.request((BEvent) req);
                 }
@@ -286,7 +291,7 @@ private EventSet convertToEventSet(Object jsObject) {
             if (arr.isEmpty()) return EventSets.none;
 
             if (Stream.of(arr.getIds()).anyMatch(id -> arr.get(id) == null)) {
-                throw new RuntimeException("EventSet Array contains null sets. Exception causing b-thread: "
+                throw new RuntimeException("EventSet Array contains null sets. B-thread name: "
                         + CURRENT_BTHREAD.get().snapshot.getName());
             }