Improving functionalities and adding unit tests

tests/test_undo_redo.py

@@ -1,7 +1,24 @@
-from components.undo_redo.components.UndoRedo import UndoRedo
-from core.settings_management import SettingsManager, MemoryDbEngine
+import pytest
+from fasthtml.components import Div
+
+from components.undo_redo.components.UndoRedo import UndoRedo, CommandHistory
+from core.settings_management import SettingsManager, MemoryDbEngine
+from helpers import matches, div_icon, Contains, DoesNotContain
+from my_mocks import tabs_manager
+
+
+class UndoableCommand(CommandHistory):
+  def __init__(self, old_value=0, new_value=0):
+    super().__init__("command", f"The new value is {new_value}")
+    self.old_value = old_value
+    self.new_value = new_value
+  
+  def undo(self):
+    return Div(self.old_value, hx_swap_oob="true")
+  
+  def redo(self):
+    return Div(self.new_value, hx_swap_oob="true")
 
-TEST_UNDO_REDO_INSTANCE_ID = "test_undo_redo_instance_id"
 
 @pytest.fixture
 def undo_redo(session, tabs_manager):
@@ -11,5 +28,74 @@ def undo_redo(session, tabs_manager):
                   tabs_manager=tabs_manager)
 
 
+def test_i_can_render(undo_redo):
+  actual = undo_redo.__ft__()
+  expected = Div(
+    Div(div_icon("undo", cls=Contains("mmt-btn-disabled")), data_tooltip="Nothing to undo"),
+    Div(div_icon("redo", cls=Contains("mmt-btn-disabled")), data_tooltip="Nothing to redo"),
+    id=undo_redo.get_id(),
+  )
+  
+  assert matches(actual, expected)
+
+
+def test_i_can_render_when_undoing_and_redoing(undo_redo):
+  undo_redo.push(UndoableCommand())
+  undo_redo.push(UndoableCommand())
+  
+  actual = undo_redo.__ft__()
+  expected = Div(
+    Div(div_icon("undo", cls=DoesNotContain("mmt-btn-disabled")), data_tooltip="Undo "),
+    Div(div_icon("redo", cls=Contains("mmt-btn-disabled")), data_tooltip=""),
+    id=undo_redo.get_id(),
+  )
+  assert matches(actual, expected)
+  
+  undo_redo.undo()  # The command is now undone. We can redo it and undo the first command.
+  actual = undo_redo.__ft__()
+  expected = Div(
+    div_icon("undo", cls=DoesNotContain("mmt-btn-disabled")),
+    div_icon("redo", cls=DoesNotContain("mmt-btn-disabled")),
+    id=undo_redo.get_id(),
+  )
+  assert matches(actual, expected)
+  
+  undo_redo.undo()  # Undo again, I cannot undo anymore.
+  actual = undo_redo.__ft__()
+  expected = Div(
+    div_icon("undo", cls=Contains("mmt-btn-disabled")),
+    div_icon("redo", cls=DoesNotContain("mmt-btn-disabled")),
+    id=undo_redo.get_id(),
+  )
+  assert matches(actual, expected)
+  
+  undo_redo.redo()  # Redo once.
+  actual = undo_redo.__ft__()
+  expected = Div(
+    div_icon("undo", cls=DoesNotContain("mmt-btn-disabled")),
+    div_icon("redo", cls=DoesNotContain("mmt-btn-disabled")),
+    id=undo_redo.get_id(),
+  )
+  assert matches(actual, expected)
+  
+  undo_redo.redo()  # Redo a second time.
+  actual = undo_redo.__ft__()
+  expected = Div(
+    div_icon("undo", cls=DoesNotContain("mmt-btn-disabled")),
+    div_icon("redo", cls=Contains("mmt-btn-disabled")),
+    id=undo_redo.get_id(),
+  )
+  assert matches(actual, expected)
+
+
 def test_i_can_undo_and_redo(undo_redo):
-  pass
+  undo_redo.push(UndoableCommand(0, 1))
+  undo_redo.push(UndoableCommand(1, 2))
+  
+  self, res = undo_redo.undo()
+  expected = Div(1, hx_swap_oob="true")
+  assert matches(res, expected)
+  
+  self, res = undo_redo.redo()
+  expected = Div(2, hx_swap_oob="true")
+  assert matches(res, expected)