fix: Address datepicker issues

shiny/ui/_input_date.py

@@ -310,6 +310,9 @@ def _date_input_tag(
 def _as_date_attr(x: Optional[date | str]) -> Optional[str]:
     if x is None:
         return None
-    if isinstance(x, date):
-        return str(x)
-    return str(date.fromisoformat(x))
+    if isinstance(x, str):
+        if len(x) == 0:
+            return x
+        x = date.fromisoformat(x)
+
+    return x.isoformat()

tests/playwright/shiny/components/datepicker/app.py

@@ -0,0 +1,76 @@
+from datetime import datetime
+
+from dateutil.relativedelta import relativedelta
+
+from shiny import App, Inputs, Outputs, Session, render, ui
+
+min_date = datetime.now()
+max_date = min_date + relativedelta(days=10)
+
+# Our input requires strings to be in the format "YYYY-MM-DD"
+str_min = min_date.strftime("%Y-%m-%d")
+str_max = max_date.strftime("%Y-%m-%d")
+
+ui = ui.page_fluid(
+    ui.input_date(
+        "start_date_picker",
+        "Date Type Input:",
+        value=max_date,
+        min=min_date,
+        max=max_date,
+        format="dd.mm.yyyy",
+        language="en",
+    ),
+    ui.output_text("start"),
+    ui.input_date(
+        "str_date_picker",
+        "String Type Input:",
+        value=str_max,
+        min=str_min,
+        max=str_max,
+        format="dd-mm-yyyy",
+        language="en",
+    ),
+    ui.output_text("str_format"),
+    ui.input_date(
+        "none_date_picker",
+        "None Type Input:",
+        value=None,
+        min=None,
+        max=None,
+        format="dd-mm-yyyy",
+        language="en",
+    ),
+    ui.output_text("none_format"),
+    ui.input_date(
+        "empty_date_picker",
+        "empty Type Input:",
+        value="",
+        min=None,
+        max=None,
+        format="dd-mm-yyyy",
+        language="en",
+    ),
+    ui.output_text("empty_format"),
+)
+
+
+def server(input: Inputs, output: Outputs, session: Session):
+    @render.text
+    def start():
+        return "Start Date Picker Value: " + str(input.start_date_picker())
+
+    @render.text
+    def str_format():
+        return "String Date Picker Value: " + str(input.str_date_picker())
+
+    @render.text
+    def none_format():
+        return "None Date Picker Value: " + str(input.none_date_picker())
+
+    @render.text
+    def empty_format():
+        return "Empty Date Picker Value: " + str(input.empty_date_picker())
+
+
+app = App(ui, server, debug=True)