fix: prevent NPE in ShortcutRegistration.toString (#17218) (#17225)

Co-authored-by: Marco Collovati <marco@vaadin.com>
vaadin · Jul 14, 2023 · c4ef634 · c4ef634
1 parent f0ea667
commit c4ef634
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Showing 2 changed files with 17 additions and 3 deletions.
diff --git a/flow-server/src/main/java/com/vaadin/flow/component/ShortcutRegistration.java b/flow-server/src/main/java/com/vaadin/flow/component/ShortcutRegistration.java
@@ -886,9 +886,11 @@ public List<String> getKeys() {
     public String toString() {
         StringBuilder builder = new StringBuilder();
         builder.append("[");
-        builder.append(Arrays.stream(listenOnComponents)
-                .map(component -> component.getClass().getSimpleName())
-                .collect(Collectors.joining(",")));
+        if (listenOnComponents != null) {
+            builder.append(Arrays.stream(listenOnComponents)
+                    .map(component -> component.getClass().getSimpleName())
+                    .collect(Collectors.joining(",")));
+        }
         builder.append("]");
         return String.format(
                 "%s [key = %s, modifiers = %s, owner = %s, listenOn = %s, "

diff --git a/flow-server/src/test/java/com/vaadin/flow/component/ShortcutRegistrationTest.java b/flow-server/src/test/java/com/vaadin/flow/component/ShortcutRegistrationTest.java
@@ -630,6 +630,18 @@ public void reattachComponent_detachListenerIsAddedOnEveryAttach_listenOnUIIsClo
         Assert.assertTrue(hasKeyAInKeyDownExpression(newUI));
     }
 
+    @Test
+    public void toString_listenOnComponentsNotInitialized_doesNotFail() {
+        ShortcutRegistration registration = new ShortcutRegistration(
+                lifecycleOwner, () -> listenOn, event -> {
+                }, Key.KEY_A);
+        Assert.assertTrue(registration.toString().contains("listenOn = []"));
+
+        clientResponse();
+        Assert.assertTrue(
+                registration.toString().matches(".*listenOn = \\[[^]]+],.*"));
+    }
+
     private Element mockLifecycle(boolean visible) {
         Mockito.when(lifecycleOwner.isVisible()).thenReturn(visible);
         Element element = ElementFactory.createAnchor();