Add a test for listener order, see #215

phetsims · Apr 5, 2023 · 97d9b18 · 97d9b18
1 parent 3e7cd95
commit 97d9b18
Showing 1 changed file with 18 additions and 0 deletions.
diff --git a/js/TinyEmitterTests.ts b/js/TinyEmitterTests.ts
@@ -186,4 +186,22 @@ QUnit.test( 'TinyEmitter onBeforeNotify', assert => {
   callForHappinessEmitter.emit();
   callForHappinessEmitter.emit();
   assert.ok( state.happiness === 5, 'end count' );
+} );
+
+QUnit.test( 'TinyEmitter reverse and random', assert => {
+
+  assert.ok( true, 'first test' );
+
+  const emitter = new TinyEmitter();
+  const values: string[] = [];
+  emitter.addListener( () => values.push( 'a' ) );
+  emitter.addListener( () => values.push( 'b' ) );
+  emitter.addListener( () => values.push( 'c' ) );
+  emitter.addListener( () => values.push( 'd' ) );
+
+  emitter.emit();
+  assert.ok( values.join( '' ) === 'abcd', 'normal order' );
+
+  // Check these values when running with ?listenerOrder=reverse or ?listenerOrder=random or ?listenerOrder=random(123)
+  console.log( values.join( '' ) );
 } );