Datasets:

ExpertCrowd
/

ec-swe

diff --git a/CHANGES.md b/CHANGES.md
index 8853860..4976b6c 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -11,6 +11,10 @@ Unreleased
 
 Unreleased
 
+- The `[default: ...]` shown in help for an option with `multiple=True`
+  renders each value the way a single value is rendered: `Enum` members by
+  name, empty strings as `""`. The prompt of an option lists its choices and
+  previews its default the same way, so what it shows can be typed back.
 - Fix `copy.deepcopy()` and `pickle` on a `Parameter`, `Option` or `Command`. {pr}`3805`
 - A `KeyboardInterrupt` arriving while `Command.main()` reports an abort or an error,
   or while it exits, no longer escapes as an unhandled traceback. The command still
diff --git a/src/click/_utils.py b/src/click/_utils.py
index 2d4e8f2..e2811bb 100644
--- a/src/click/_utils.py
+++ b/src/click/_utils.py
@@ -1,7 +1,9 @@
 from __future__ import annotations
 
 import enum
+import inspect
 import typing as t
+from gettext import gettext as _
 
 
 class Sentinel(enum.Enum):
@@ -43,3 +45,33 @@ T_UNSET: t.TypeAlias = t.Literal[Sentinel.UNSET]
 
 T_FLAG_NEEDS_VALUE: t.TypeAlias = t.Literal[Sentinel.FLAG_NEEDS_VALUE]
 """Type hint for the :data:`FLAG_NEEDS_VALUE` sentinel value."""
+
+
+def _format_default_value(value: t.Any) -> str:
+    """Render a value the way ``[default: ...]`` and prompts show it.
+
+    A list or tuple renders as its values, comma separated, each rendered by
+    the same rules as a single value: an Enum member by its name, an empty
+    string as ``""``, a plain function as ``(dynamic)``, anything else with
+    ``str()``.
+
+    :meta private:
+    """
+    if isinstance(value, (list, tuple)):
+        return ", ".join(_format_default_value(item) for item in value)
+    if isinstance(value, enum.Enum):
+        return value.name
+    if inspect.isfunction(value):
+        return _("(dynamic)")
+    if isinstance(value, str) and value == "":
+        return '""'
+    return str(value)
+
+
+def _format_choice(choice: t.Any) -> str:
+    """Render one choice the way prompts and help list it: an Enum member by
+    its name, anything else with ``str()``.
+
+    :meta private:
+    """
+    return choice.name if isinstance(choice, enum.Enum) else str(choice)
diff --git a/src/click/core.py b/src/click/core.py
index 1f9323a..e82eaa0 100644
--- a/src/click/core.py
+++ b/src/click/core.py
@@ -23,6 +23,7 @@ from types import TracebackType
 
 from . import types
 from ._utils import FLAG_NEEDS_VALUE
+from ._utils import _format_default_value
 from ._utils import UNSET
 from .exceptions import Abort
 from .exceptions import BadParameter
@@ -3564,12 +3565,13 @@ class Option(Parameter):
         ):
             if show_default_is_str:
                 default_string = f"({self.show_default})"
-            elif isinstance(default_value, (list, tuple)):
-                default_string = ", ".join(str(d) for d in default_value)
-            elif isinstance(default_value, enum.Enum):
-                default_string = default_value.name
-            elif inspect.isfunction(default_value):
-                default_string = _("(dynamic)")
+            elif isinstance(default_value, (list, tuple)) or (
+                isinstance(default_value, enum.Enum)
+                or inspect.isfunction(default_value)
+            ):
+                # Multi-valued defaults render each value the way the same
+                # value renders for a single-valued option.
+                default_string = _format_default_value(default_value)
             elif self.is_bool_flag and self.secondary_opts:
                 # For boolean flags that have distinct True/False opts,
                 # use the opt without prefix instead of the value.
diff --git a/src/click/termui.py b/src/click/termui.py
index 8fe0085..0caa7cd 100644
--- a/src/click/termui.py
+++ b/src/click/termui.py
@@ -15,6 +15,8 @@ from gettext import gettext as _
 from . import _compat
 from ._compat import isatty
 from ._compat import strip_ansi
+from ._utils import _format_choice
+from ._utils import _format_default_value
 from .exceptions import Abort
 from .exceptions import UsageError
 from .globals import resolve_color_default
@@ -115,7 +117,9 @@ def _build_prompt(
 ) -> str:
     prompt = text
     if type is not None and show_choices and isinstance(type, Choice):
-        prompt += f" ({', '.join(map(str, type.choices))})"
+        # Each choice is listed the way it can be typed back, which for an
+        # Enum member is its name, as the help and the error message show it.
+        prompt += f" ({', '.join(_format_choice(choice) for choice in type.choices)})"
     default_preview = ""
     if show_default:
         if isinstance(show_default, str):
@@ -132,7 +136,9 @@ def _format_default(default: V) -> V | str:
         if name is not None:
             return str(name)
 
-    return default
+    # The default is previewed the way the help renders it, so that what is
+    # shown is what the user can type back.
+    return _format_default_value(default)
 
 
 @t.overload
@@ -250,6 +256,15 @@ def prompt(
     prompt = _build_prompt(
         text, prompt_suffix, show_default, default, show_choices, type
     )
+    # The default exactly as the prompt shows it. Typing that text back
+    # selects the default itself, as pressing Enter does, so that a value
+    # rendered for display (a quoted empty string, a list of values) can be
+    # typed back as shown.
+    shown_default = (
+        str(_format_default(default))
+        if default is not None and show_default and not isinstance(show_default, str)
+        else None
+    )
 
     if confirmation_prompt:
         if confirmation_prompt is True:
@@ -269,7 +284,9 @@ def prompt(
                 value = t.cast("str", default)
                 break
         try:
-            result = value_proc(value)
+            result = value_proc(
+                default if shown_default is not None and value == shown_default else value
+            )
         except UsageError as e:
             message = _mask_hidden_input(e.message, value) if hide_input else e.message
             echo(_("Error: {message}").format(message=message), err=err)
diff --git a/tests/test_help_defaults_multiple.py b/tests/test_help_defaults_multiple.py
new file mode 100644
index 0000000..cb6eb77
--- /dev/null
+++ b/tests/test_help_defaults_multiple.py
@@ -0,0 +1,69 @@
+import enum
+
+import click
+from click.testing import CliRunner
+
+
+class Color(enum.Enum):
+    Red = "r"
+    Blue = "b"
+
+
+def _help(**kwargs):
+    @click.command()
+    @click.option("--opt", show_default=True, **kwargs)
+    def cmd(opt):
+        pass
+
+    return CliRunner().invoke(cmd, ["--help"]).output
+
+
+def test_multiple_enum_default_shows_names():
+    assert "[default: Red, Blue]" in _help(
+        type=click.Choice(Color), multiple=True, default=[Color.Red, Color.Blue]
+    )
+
+
+def test_multiple_empty_string_default_is_quoted():
+    assert '[default: "", x]' in _help(multiple=True, default=["", "x"])
+
+
+def test_nargs_with_multiple_renders_every_value():
+    assert "[default: 1, 2, 3, 4]" in _help(nargs=2, multiple=True, default=[(1, 2), (3, 4)])
+
+
+def _prompt_line(input_text="\n", **kwargs):
+    @click.command()
+    @click.option("--opt", prompt="Value", **kwargs)
+    def cmd(opt):
+        pass
+
+    return CliRunner().invoke(cmd, [], input=input_text).output.split("\n", 1)[0]
+
+
+def test_prompt_lists_enum_choices_and_default_by_name():
+    line = _prompt_line(type=click.Choice(Color), default=Color.Blue)
+    assert "(Red, Blue)" in line
+    assert "[Blue]" in line
+
+
+def test_prompt_previews_empty_string_default_quoted():
+    assert '[""]' in _prompt_line(default="")
+
+
+def test_prompt_default_typed_back_as_shown():
+    line = CliRunner().invoke(
+        _typed_back_cmd(multiple=True, default=["", "x"]), [], input='"", x\n'
+    ).output
+    assert "GOT=('', 'x')" in line
+    line = CliRunner().invoke(_typed_back_cmd(default=""), [], input='""\n').output
+    assert "GOT=''" in line
+
+
+def _typed_back_cmd(**kwargs):
+    @click.command()
+    @click.option("--opt", prompt="Value", **kwargs)
+    def cmd(opt):
+        click.echo(f"GOT={opt!r}")
+
+    return cmd