Invoke promise fix (#208)

* fix: do not fire promise events after state changes

* chore: update tests

* Add a changeset

Create odd-lizards-guess.md

* Fix typo

Co-authored-by: edwardsnjd <[email protected]>

* Fix typo

Co-authored-by: edwardsnjd <[email protected]>

---------

Co-authored-by: Ruslan Kyba <[email protected]>
Co-authored-by: edwardsnjd <[email protected]>

.changeset/odd-lizards-guess.md

@@ -0,0 +1,5 @@
+---
+"robot3": patch
+---
+
+Don't make a state transition if the state is left before the invoked promise resolves, *even* if there's a transition with the same name.

packages/core/machine.js

@@ -89,8 +89,15 @@ let invokeFnType = {
         machine: valueEnumerable(rn),
         transitions: valueEnumerable(this.transitions)
       }).enter(machine2, service, event)
-    rn.then(data => service.send({ type: 'done', data }))
-      .catch(error => service.send({ type: 'error', error }));
+    rn
+      .then(data => { 
+        if (machine2 === service.machine) 
+          return service.send({ type: 'done', data });
+      })
+      .catch(error => { 
+        if (machine2 === service.machine) 
+          return service.send({ type: 'error', error });
+      });
     return machine2;
   }
 };

packages/core/test/test-invoke.js

@@ -52,6 +52,50 @@ QUnit.module('Invoke', hooks => {
     assert.equal(service.machine.current, 'two', 'in the new state');
   });
 
+  QUnit.test('Should not fire "done" event when state changes', async assert => {
+    const wait = ms => () => new Promise(resolve => setTimeout(resolve, ms));
+
+    let machine = createMachine({
+      one: state(transition('click', 'two')),
+      two: invoke(wait(10),
+        transition('done', 'one'),
+        transition('click', 'three')
+      ),
+      three: state(
+        transition('done', 'error'),
+      ),
+      error: state(),
+    });
+
+    let service = interpret(machine, () => { });
+    service.send('click');
+    service.send('click');
+    await wait(15)()
+    assert.equal(service.machine.current, 'three', 'now in the next state');
+  });
+
+  QUnit.test('Should fire "done" when context changes', async assert => {
+    const wait = ms => () => new Promise(resolve => setTimeout(resolve, ms));
+
+    let machine = createMachine({
+      one: state(transition('click', 'two')),
+      two: invoke(wait(10),
+        transition('done', 'three'),
+        transition('click', 'two', reduce((ctx) => ({ value: ctx.value + 1 })))
+      ),
+      three: state(),
+      error: state(),
+    }, () => ({ value: 0 }));
+
+    let service = interpret(machine, () => { });
+    service.send('click');
+    service.send('click');
+    service.send('click');
+    await wait(15)()
+    assert.equal(service.context.value, 2, 'value should be 2');
+    assert.equal(service.machine.current, 'three', 'now in the correct state');
+  });
+
   QUnit.module('Machine');
 
   QUnit.test('Can invoke a child machine', async assert => {