diff --git a/test/fixtures/tw-hats-and-events.sb3 b/test/fixtures/tw-hats-and-events.sb3
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index 00000000000..ad8c5ad7dc1
Binary files /dev/null and b/test/fixtures/tw-hats-and-events.sb3 differ
diff --git a/test/integration/tw_hats_and_events.js b/test/integration/tw_hats_and_events.js
new file mode 100644
index 00000000000..98031c22595
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+++ b/test/integration/tw_hats_and_events.js
@@ -0,0 +1,192 @@
+const fs = require('fs');
+const path = require('path');
+const {test} = require('tap');
+const VM = require('../../src/virtual-machine');
+const BlockType = require('../../src/extension-support/block-type');
+const ArgumentType = require('../../src/extension-support/argument-type');
+
+const compilerAndInterpreter = (name, callback) => {
+    test(`${name} - interpreted`, t => {
+        callback(t, {
+            enabled: false
+        });
+    });
+    test(`${name} - compiled`, t => {
+        callback(t, {
+            enabled: true
+        });
+    });
+};
+
+const fixture = fs.readFileSync(path.join(__dirname, '..', 'fixtures', 'tw-hats-and-events.sb3'));
+
+compilerAndInterpreter('hats and events', (t, co) => {
+    const vm = new VM();
+    vm.setCompilerOptions(co);
+
+    let log = [];
+    let hatReturns = false;
+    class TestExtension {
+        getInfo () {
+            return {
+                id: 'testpredicate',
+                name: 'Test Predicate',
+                blocks: [
+                    {
+                        opcode: 'event',
+                        blockType: BlockType.EVENT,
+                        text: 'event block',
+                        isEdgeActivated: false
+                    },
+                    {
+                        opcode: 'hat',
+                        blockType: BlockType.HAT,
+                        text: 'hat block',
+                        isEdgeActivated: false
+                    },
+                    {
+                        opcode: 'complexhat',
+                        blockType: BlockType.HAT,
+                        text: 'complex hat [MENU] if [INPUT]',
+                        isEdgeActivated: false,
+                        arguments: {
+                            MENU: {
+                                menu: 'test'
+                            },
+                            INPUT: {
+                                type: ArgumentType.STRING,
+                                defaultValue: 'default'
+                            }
+                        }
+                    }
+                ],
+                menus: {
+                    test: {
+                        acceptReporters: false,
+                        items: ['a', 'b', 'c']
+                    }
+                }
+            };
+        }
+        event () {
+            log.push('this should never run');
+        }
+        hat () {
+            log.push(`hat ${hatReturns}`);
+            return hatReturns;
+        }
+        complexhat ({INPUT}) {
+            log.push(`complex hat ${INPUT}`);
+            return !!INPUT;
+        }
+    }
+    vm.extensionManager.addBuiltinExtension('testpredicate', TestExtension);
+
+    vm.on('COMPILE_ERROR', () => {
+        t.fail('Compile error');
+    });
+
+    vm.loadProject(fixture).then(async () => {
+        log = vm.runtime.getTargetForStage().lookupVariableByNameAndType('log', 'list').value;
+        t.same(log, [], 'sanity check - log starts empty');
+
+        // Let it run for a bit. Nothing should happen on its own.
+        for (let i = 0; i < 5; i++) {
+            vm.runtime._step();
+        }
+        t.same(log, [], 'nothing happens initially');
+
+        // See if events work
+        vm.runtime.startHats('testpredicate_event');
+        t.same(log, [], 'event function does not get called, even if it exists');
+        vm.runtime._step();
+        t.same(log, ['event'], 'ran event script');
+
+        log.length = 0;
+
+        // Test hat that returns false
+        hatReturns = false;
+        vm.runtime.startHats('testpredicate_hat');
+        t.same(log, ['hat false'], 'ran hat function');
+        vm.runtime._step();
+        t.same(log, ['hat false'], 'did not run hat script');
+
+        // Test hat that returns true
+        hatReturns = true;
+        vm.runtime.startHats('testpredicate_hat');
+        t.same(log, [
+            'hat false',
+            'hat true'
+        ], 'ran hat function');
+        vm.runtime._step();
+        t.same(log, [
+            'hat false',
+            'hat true',
+            'hat'
+        ], 'ran hat script');
+
+        log.length = 0;
+
+        // Test hat that returns false in a Promise
+        hatReturns = Promise.resolve(false);
+        vm.runtime.startHats('testpredicate_hat');
+        t.same(log, ['hat [object Promise]'], 'ran hat function');
+        vm.runtime._step();
+        t.same(log, ['hat [object Promise]'], 'hat script does not run before promise finishes');
+        await Promise.resolve(); // Allow promise to be processed
+        vm.runtime._step();
+        t.same(log, ['hat [object Promise]'], 'hat script still does not run');
+
+        log.length = 0;
+
+        // Test hat that returns true in a Promise
+        hatReturns = Promise.resolve(true);
+        vm.runtime.startHats('testpredicate_hat');
+        t.same(log, ['hat [object Promise]'], 'ran hat function');
+        vm.runtime._step();
+        t.same(log, ['hat [object Promise]'], 'hat script does not run before promise finishes');
+        await Promise.resolve();
+        vm.runtime._step();
+        t.same(log, ['hat [object Promise]', 'hat'], 'hat script runs after promise finishes');
+
+        log.length = 0;
+
+        // Test complex hat
+        vm.runtime.startHats('testpredicate_complexhat', {
+            MENU: 'a'
+        });
+        t.same(log, [
+            'complex hat ',
+            'complex hat 1'
+        ], 'ran complex hat functions');
+        vm.runtime._step();
+        t.same(log, [
+            'complex hat ',
+            'complex hat 1',
+            'complex hat a 2'
+        ], 'ran complex hat script');
+
+        log.length = 0;
+
+        // Test complex hat with a complex input
+        vm.runtime.startHats('testpredicate_complexhat', {
+            MENU: 'b'
+        });
+        t.same(log, [], 'control flow in complex inputs is not run immediately');
+        vm.runtime._step();
+        t.same(log, [
+            'evaluated block ',
+            'evaluated block 1'
+        ], 'evaluated complex inputs but not hat function');
+        vm.runtime._step();
+        t.same(log, [
+            'evaluated block ',
+            'evaluated block 1',
+            'complex hat ',
+            'complex hat 1',
+            'complex hat b 2'
+        ], 'evaluated complex hat functions and scripts');
+
+        t.end();
+    });
+});