add skeleton tests

these will be implemented later

Author: rmorshea

docs/source/getting-started.rst

@@ -8,6 +8,7 @@ Let's look at the example that you may have seen
 
     import idom
 
+
     @idom.element
     async def Slideshow():
         index, set_index = idom.hooks.use_state(0)
@@ -23,6 +24,7 @@ Let's look at the example that you may have seen
             }
         )
 
+
     host, port = "localhost", 8765
     server = idom.server.sanic.PerClientStateServer(Slideshow)
     server.run(host, port)

tests/test_core/test_hooks.py

@@ -52,6 +52,29 @@ async def SimpleStatefulElement():
         ]
 
 
+async def test_set_state_callback_identity_is_preserved():
+    saved_set_state_hooks = []
+
+    @idom.element
+    async def SimpleStatefulElement():
+        index, set_index = idom.hooks.use_state(0)
+        saved_set_state_hooks.append(set_index)
+        set_index(index + 1)
+        return idom.html.div(index)
+
+    sse = SimpleStatefulElement()
+
+    async with idom.Layout(sse) as layout:
+        await layout.render()
+        await layout.render()
+        await layout.render()
+        await layout.render()
+
+    first_hook = saved_set_state_hooks[0]
+    for h in saved_set_state_hooks[1:]:
+        assert first_hook is h
+
+
 def test_use_state_with_constructor(driver, display, driver_wait):
     constructor_call_count = idom.Ref(0)
 
@@ -113,7 +136,15 @@ async def on_click(event):
     assert count.get_attribute("innerHTML") == "1"
 
 
-def test_simple_input(driver, display):
+def test_set_state_with_reducer_instead_of_value():
+    assert False
+
+
+def test_set_state_checks_identity_not_equality():
+    assert False
+
+
+def test_simple_input_with_use_state(driver, display):
     message_ref = idom.Ref(None)
 
     @idom.element
@@ -139,12 +170,49 @@ 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
+
+
+def test_use_effect_cleanup_occurs_on_will_render():
+    assert False
+
+
+def test_use_effect_cleanup_occurs_on_will_unmount():
+    assert False
+
+
+def test_use_effect_memoization():
+    assert False
+
+
+def test_use_reducer():
+    assert False
+
+
+def test_use_reducer_dispatch_callback_identity_is_preserved():
+    assert False
+
+
+def test_use_callback_identity():
+    assert False
+
+
+def test_use_callback_memoization():
+    assert False
+
+
 def test_use_memo(display, driver, driver_wait):
     trigger_count = 0
 
+    # use constants to ensure identity comparison works as expected
+    left_const = "left"
+    right_const = "right"
+
     @idom.element
     async def ComponentWithMemo():
-        location, set_location = idom.hooks.use_state("left")
+        location, set_location = idom.hooks.use_state(left_const)
 
         @idom.hooks.use_memo(args=location)
         def count():
@@ -153,10 +221,10 @@ def count():
             return trigger_count
 
         async def on_left_button_click(event):
-            set_location("left")
+            set_location(left_const)
 
         async def on_right_button_click(event):
-            set_location("right")
+            set_location(right_const)
 
         return idom.html.div(
             idom.html.button(
@@ -181,3 +249,19 @@ async def on_right_button_click(event):
     right_client_button.click()  # trigger: yes
 
     driver_wait.until(lambda drv: trigger_count == 4)
+
+
+def test_use_memo_always_runs_if_args_are_none():
+    assert False
+
+
+def test_use_memo_never_runs_if_args_args_empty_list():
+    assert False
+
+
+def test_use_memo_decorator_and_non_decorator_usage():
+    assert False
+
+
+def test_use_ref():
+    assert False

tests/test_core/test_layout.py

@@ -252,3 +252,7 @@ async def Inner():
     del layout
     gc.collect()
     assert not live_elements
+
+
+def test_double_updated_element_is_not_double_rendered():
+    assert False