Add test legacy components.

Author: T4rk1n

tests/unit/development/test_legacy_components.py

@@ -0,0 +1,53 @@
+from dash import Dash
+from dash.development.base_component import Component, _explicitize_args
+
+# Import to load into registry.
+import dash_generator_test_component_standard  # noqa: F401
+
+
+class PreCAPLegacyComponent(Component):
+    """A MyStandardComponent component.
+    MyComponent description
+
+    Keyword arguments:
+
+    - id (string; optional):
+        The id of the component.
+
+    - style (optional):
+        The style.
+
+    - value (string; default ''):
+        The value to display.
+
+    Note: due to the large number of props for this component,
+    not all of them appear in the constructor signature, but
+    they may still be used as keyword arguments."""
+
+    @_explicitize_args
+    def __init__(self, id=Component.UNDEFINED, style=Component.UNDEFINED, **kwargs):
+        self._prop_names = ["id", "style", "value"]
+        self._type = "MyStandardComponent"
+        self._namespace = "dash_generator_test_component_standard"
+        self._valid_wildcard_attributes = []
+        self.available_properties = ["id", "style", "value"]
+        self.available_wildcard_properties = []
+        _explicit_args = kwargs.pop("_explicit_args")
+        _locals = locals()
+        _locals.update(kwargs)  # For wildcard attrs and excess named props
+        args = {k: _locals[k] for k in _explicit_args if k != "children"}
+        for k in []:
+            if k not in args:
+                raise TypeError("Required argument `" + k + "` was not specified.")
+        super(PreCAPLegacyComponent, self).__init__(**args)
+
+
+def test_leg001_legacy_pre_component_as_props(dash_duo):
+    app = Dash(__name__)
+
+    app.layout = PreCAPLegacyComponent(id="pre-cap", value="legacy")
+
+    dash_duo.start_server(app)
+
+    dash_duo.wait_for_text_to_equal("#pre-cap", "legacy")
+    assert dash_duo.get_logs() == []