test use_effect + remove Ref.set method

Author: rmorshea

idom/core/hooks.py

@@ -236,10 +236,10 @@ def use_memo(
     if memo.empty():
         # we need to initialize on the first run
         changed = True
-        memo.args = args
+        memo.args = () if args is None else args
     elif (
         args is None
-        or len(memo.args) != args
+        or len(memo.args) != len(args)
         or any(current is not new for current, new in zip(memo.args, args))
     ):
         memo.args = args

idom/utils.py

@@ -25,10 +25,6 @@ class Ref(Generic[_Current]):
     def __init__(self, initial_value: _Current) -> None:
         self.current = initial_value
 
-    def set(self, value: _Current) -> None:
-        self.current = value
-        return None
-
     def __eq__(self, other: Any) -> bool:
         return isinstance(other, Ref) and (other.current == self.current)
 

tests/conftest.py

@@ -221,11 +221,11 @@ class ServerSavesLastError(server_type):
         """A per-client-state server that updates the ``last_server_error`` fixture"""
 
         async def _run_renderer(self, *args, **kwargs):
-            self._config["last_server_error"].set(None)
+            self._config["last_server_error"].current = None
             try:
                 await super()._run_renderer(*args, **kwargs)
             except Exception as e:
-                self._config["last_server_error"].set(e)
+                self._config["last_server_error"].current = e
 
     return ServerSavesLastError
 
@@ -261,7 +261,7 @@ def last_server_error():
 
 @pytest.fixture(autouse=True)
 def _clean_last_server_error(last_server_error) -> Iterator[None]:
-    last_server_error.set(default_error)
+    last_server_error.current = default_error
     yield
 
 

tests/test_core/test_hooks.py

@@ -231,7 +231,7 @@ def test_simple_input_with_use_state(driver, display):
     @idom.element
     async def Input(message=None):
         message, set_message = idom.hooks.use_state(message)
-        message_ref.set(message)
+        message_ref.current = message
 
         async def on_change(event):
             if event["value"] == "this is a test":
@@ -251,21 +251,143 @@ async def on_change(event):
     assert message_ref.current == "this is a test"
 
 
-def test_use_effect_callback_occurs_after_full_layout_update_is_complete():
-    # TODO: right now it runs after the element is rendered, not the full layout update
-    assert False
+async def test_use_effect_callback_occurs_after_full_render_is_complete():
+    effect_triggered = idom.Ref(False)
+    effect_triggers_after_final_render = idom.Ref(None)
 
+    @idom.element
+    async def OuterElement():
+        return idom.html.div(
+            ElementWithEffect(),
+            CheckNoEffectYet(),
+        )
 
-def test_use_effect_cleanup_occurs_on_will_render():
-    assert False
+    @idom.element
+    async def ElementWithEffect():
+        @idom.hooks.use_effect
+        def effect():
+            effect_triggered.current = True
 
+        return idom.html.div()
 
-def test_use_effect_cleanup_occurs_on_will_unmount():
-    assert False
+    @idom.element
+    async def CheckNoEffectYet():
+        effect_triggers_after_final_render.current = not effect_triggered.current
+        return idom.html.div()
 
+    async with idom.Layout(OuterElement()) as layout:
+        await layout.render()
 
-def test_use_effect_memoization():
-    assert False
+    assert effect_triggered.current
+    assert effect_triggers_after_final_render.current is not None
+    assert effect_triggers_after_final_render.current
+
+
+async def test_use_effect_cleanup_occurs_on_will_render():
+    element_hook = idom.Ref(None)
+    cleanup_triggered = idom.Ref(False)
+    cleanup_triggered_before_next_render = idom.Ref(False)
+
+    @idom.element
+    async def ElementWithEffect():
+        element_hook.current = idom.hooks.current_hook()
+        if cleanup_triggered.current:
+            cleanup_triggered_before_next_render.current = True
+
+        @idom.hooks.use_effect
+        def effect():
+            def cleanup():
+                cleanup_triggered.current = True
+
+            return cleanup
+
+        return idom.html.div()
+
+    async with idom.Layout(ElementWithEffect()) as layout:
+        await layout.render()
+
+        assert not cleanup_triggered.current
+
+        element_hook.current.schedule_render()
+        await layout.render()
+
+        assert cleanup_triggered.current
+        assert cleanup_triggered_before_next_render.current
+
+
+async def test_use_effect_cleanup_occurs_on_will_unmount():
+    outer_element_hook = idom.Ref(None)
+    cleanup_triggered = idom.Ref(False)
+    cleanup_triggered_before_next_render = idom.Ref(False)
+
+    @idom.element
+    async def OuterElement():
+        outer_element_hook.current = idom.hooks.current_hook()
+        if cleanup_triggered.current:
+            cleanup_triggered_before_next_render.current = True
+        return ElementWithEffect()
+
+    @idom.element
+    async def ElementWithEffect():
+        @idom.hooks.use_effect
+        def effect():
+            def cleanup():
+                cleanup_triggered.current = True
+
+            return cleanup
+
+        return idom.html.div()
+
+    async with idom.Layout(OuterElement()) as layout:
+        await layout.render()
+
+        assert not cleanup_triggered.current
+
+        outer_element_hook.current.schedule_render()
+        await layout.render()
+
+        assert cleanup_triggered.current
+        assert cleanup_triggered_before_next_render.current
+
+
+async def test_use_effect_memoization():
+    element_hook = idom.Ref(None)
+    set_state_callback = idom.Ref(None)
+    effect_run_count = idom.Ref(0)
+
+    first_value = 1
+    second_value = 2
+
+    @idom.element
+    async def ElementWithMemoizedEffect():
+        element_hook.current = idom.hooks.current_hook()
+        state, set_state_callback.current = idom.hooks.use_state(first_value)
+
+        @idom.hooks.use_effect(args=[state])
+        def effect():
+            effect_run_count.current += 1
+
+        return idom.html.div()
+
+    async with idom.Layout(ElementWithMemoizedEffect()) as layout:
+        await layout.render()
+
+        assert effect_run_count.current == 1
+
+        element_hook.current.schedule_render()
+        await layout.render()
+
+        assert effect_run_count.current == 1
+
+        set_state_callback.current(second_value)
+        await layout.render()
+
+        assert effect_run_count.current == 2
+
+        element_hook.current.schedule_render()
+        await layout.render()
+
+        assert effect_run_count.current == 2
 
 
 def test_use_reducer():

tests/test_core/test_layout.py

@@ -61,7 +61,7 @@ async def test_simple_layout():
     @idom.element
     async def SimpleElement(tag):
         tag, set_tag = idom.hooks.use_state(tag)
-        set_state_hook.set(set_tag)
+        set_state_hook.current = set_tag
         return idom.vdom(tag)
 
     element = SimpleElement("div")

tests/test_utils.py

@@ -6,7 +6,6 @@
 
 def test_basic_ref_behavior():
     r = idom.Ref(None)
-    r.set("new_1")
     assert r.current == "new_1"
     r.current = "new_2"
     assert r.current == "new_2"

tests/test_widgets/test_jupyter.py

@@ -39,7 +39,7 @@ def test_cross_origin_jupyter_display(server, driver, driver_wait, mount, server
     async def SimpleButton():
         @idom.event
         async def on_click(event):
-            clicked.set(True)
+            clicked.current = True
 
         return idom.html.button(
             {"id": "simple-button", "onClick": on_click}, "click me cross origin"
@@ -88,7 +88,7 @@ def test_same_origin_jupyter_display(driver, driver_wait, mount, server_url):
     async def SimpleButton():
         @idom.event
         async def on_click(event):
-            clicked.set(True)
+            clicked.current = True
 
         return idom.html.button(
             {"id": "simple-button", "onClick": on_click}, "click me same origin"