Merge pull request #2086 from pallets/default-type-cast

getting default value doesn't perform type cast

CHANGES.rst

@@ -22,6 +22,8 @@ Unreleased
     adding underline. :pr:`2058`
 -   An option with ``count=True`` will not show "[x>=0]" in help text.
     :issue:`2072`
+-   Default values are not cast to the parameter type twice during
+    processing. :issue:`2085`
 
 
 Version 8.0.1

src/click/core.py

@@ -2192,6 +2192,9 @@ def get_default(
         :param call: If the default is a callable, call it. Disable to
             return the callable instead.
 
+        .. versionchanged:: 8.0.2
+            Type casting is no longer performed when getting a default.
+
         .. versionchanged:: 8.0.1
             Type casting can fail in resilient parsing mode. Invalid
             defaults will not prevent showing help text.
@@ -2207,20 +2210,10 @@ def get_default(
         if value is None:
             value = self.default
 
-        if callable(value):
-            if not call:
-                # Don't type cast the callable.
-                return value
-
+        if call and callable(value):
             value = value()
 
-        try:
-            return self.type_cast_value(ctx, value)
-        except BadParameter:
-            if ctx.resilient_parsing:
-                return value
-
-            raise
+        return value
 
     def add_to_parser(self, parser: OptionParser, ctx: Context) -> None:
         raise NotImplementedError()
@@ -2305,8 +2298,7 @@ def value_is_missing(self, value: t.Any) -> bool:
         return False
 
     def process_value(self, ctx: Context, value: t.Any) -> t.Any:
-        if value is not None:
-            value = self.type_cast_value(ctx, value)
+        value = self.type_cast_value(ctx, value)
 
         if self.required and self.value_is_missing(value):
             raise MissingParameter(ctx=ctx, param=self)

tests/test_options.py

@@ -252,7 +252,7 @@ def test_multiple_default_composite_type():
     assert isinstance(opt.type, click.Tuple)
     assert opt.type.types == [click.INT, click.STRING]
     ctx = click.Context(click.Command("test"))
-    assert opt.get_default(ctx) == ((1, "a"),)
+    assert opt.type_cast_value(ctx, opt.get_default(ctx)) == ((1, "a"),)
 
 
 def test_parse_multiple_default_composite_type(runner):
@@ -323,12 +323,27 @@ def test_intrange_default_help_text(type, expect):
 
 def test_count_default_type_help():
     """A count option with the default type should not show >=0 in help."""
-    option = click.Option(["--couunt"], count=True, help="some words")
+    option = click.Option(["--count"], count=True, help="some words")
     context = click.Context(click.Command("test"))
     result = option.get_help_record(context)[1]
     assert result == "some words"
 
 
+def test_file_type_help_default():
+    """The default for a File type is a filename string. The string
+    should be displayed in help, not an open file object.
+
+    Type casting is only applied to defaults in processing, not when
+    getting the default value.
+    """
+    option = click.Option(
+        ["--in"], type=click.File(), default=__file__, show_default=True
+    )
+    context = click.Context(click.Command("test"))
+    result = option.get_help_record(context)[1]
+    assert __file__ in result
+
+
 def test_toupper_envvar_prefix(runner):
     @click.command()
     @click.option("--arg")