I can bind elements

tests/core/test_bindings.py

@@ -0,0 +1,96 @@
+from dataclasses import dataclass
+
+import pytest
+from fasthtml.components import Label, Input
+from myutils.observable import collect_return_values
+
+from myfasthtml.core.bindings import BindingsManager, Binding
+
+
+@dataclass
+class Data:
+  value: str = "Hello World"
+
+
+@pytest.fixture(autouse=True)
+def reset_binding_manager():
+  BindingsManager.reset()
+
+
+@pytest.fixture()
+def data():
+  return Data()
+
+
+def test_i_can_register_a_binding(data):
+  binding = Binding(data, "value")
+  
+  assert binding.id is not None
+  assert binding.data is data
+  assert binding.data_attr == 'value'
+
+
+def test_i_can_register_a_binding_with_default_attr(data):
+  binding = Binding(data)
+  
+  assert binding.id is not None
+  assert binding.data is data
+  assert binding.data_attr == 'value'
+
+
+def test_i_can_retrieve_a_registered_binding(data):
+  binding = Binding(data)
+  assert BindingsManager.get_binding(binding.id) is binding
+
+
+def test_i_can_reset_bindings(data):
+  Binding(data)
+  assert len(BindingsManager.bindings) != 0
+  
+  BindingsManager.reset()
+  assert len(BindingsManager.bindings) == 0
+
+
+def test_i_can_bind_an_element_to_a_binding(data):
+  elt = Label("hello", id="label_id")
+  Binding(data, ft=elt)
+  
+  data.value = "new value"
+  
+  assert elt.children[0] == "new value"
+  assert elt.attrs["hx-swap-oob"] == "true"
+  assert elt.attrs["id"] == "label_id"
+
+
+def test_i_can_bind_an_element_attr_to_a_binding(data):
+  elt = Input(value="somme value", id="input_id")
+  
+  Binding(data, ft=elt, ft_attr="value")
+  
+  data.value = "new value"
+  
+  assert elt.attrs["value"] == "new value"
+  assert elt.attrs["hx-swap-oob"] == "true"
+  assert elt.attrs["id"] == "input_id"
+
+
+def test_bound_element_has_an_id():
+  elt = Label("hello")
+  assert elt.attrs.get("id", None) is None
+  
+  Binding(Data(), ft=elt)
+  assert elt.attrs.get("id", None) is not None
+
+
+def test_i_can_collect_updates_values(data):
+  elt = Label("hello")
+  Binding(data, ft=elt)
+  
+  data.value = "new value"
+  collected = collect_return_values(data)
+  assert collected == [elt]
+  
+  # a second time to ensure no side effect
+  data.value = "another value"
+  collected = collect_return_values(data)
+  assert collected == [elt]