Rebase and fix tests.

src/click/types.py

@@ -354,16 +354,12 @@ def get_invalid_choice_message(self, value: t.Any, ctx: Context | None) -> str:
 
         .. versionadded:: 8.2
         """
-        choices_str = ", ".join(self.normalized_mapping(ctx=ctx).values())
-        self.fail(
-            message=ngettext(
-                "{value!r} is not {choice}.",
-                "{value!r} is not one of {choices}.",
-                len(self.choices),
-            ).format(value=value, choice=choices_str, choices=choices_str),
-            param=value,
-            ctx=ctx,
-        )
+        choices_str = ", ".join(map(repr, self.normalized_mapping(ctx=ctx).values()))
+        return ngettext(
+            "{value!r} is not {choice}.",
+            "{value!r} is not one of {choices}.",
+            len(self.choices),
+        ).format(value=value, choice=choices_str, choices=choices_str)
 
     def __repr__(self) -> str:
         return f"Choice({list(self.choices)})"

tests/test_basic.py

@@ -387,25 +387,34 @@ def test_choice_option_normalization(runner):
     @click.option(
         "--method",
         type=click.Choice(
-            ["SCREAMING_SNAKE_CASE", "snake_case", "PascalCase", "kebab-case"]
+            ["SCREAMING_SNAKE_CASE", "snake_case", "PascalCase", "kebab-case"],
+            case_sensitive=False,
         ),
     )
     def cli(method):
         click.echo(method)
 
-    result = runner.invoke(cli, ["--method=foo"])
-    assert not result.exception
-    assert result.output == "foo\n"
+    result = runner.invoke(cli, ["--method=snake_case"])
+    assert not result.exception, result.output
+    assert result.output == "snake_case\n"
+
+    # Even though it's case sensitive, the choice's original value is preserved
+    result = runner.invoke(cli, ["--method=pascalcase"])
+    assert not result.exception, result.output
+    assert result.output == "PascalCase\n"
 
     result = runner.invoke(cli, ["--method=meh"])
     assert result.exit_code == 2
     assert (
         "Invalid value for '--method': 'meh' is not one of "
-        "'screaming-snake-case', 'snake-case', 'pascalcase', 'kebab-case'."
+        "'screaming_snake_case', 'snake_case', 'pascalcase', 'kebab-case'."
     ) in result.output
 
     result = runner.invoke(cli, ["--help"])
-    assert "--method [foo|bar|baz]" in result.output
+    assert (
+        "--method [screaming_snake_case|snake_case|pascalcase|kebab-case]"
+        in result.output
+    )
 
 
 def test_choice_argument(runner):

tests/test_types.py

@@ -248,5 +248,5 @@ def test_invalid_path_with_esc_sequence():
 
 def test_choice_get_invalid_choice_message():
     choice = click.Choice(["a", "b", "c"])
-    message = choice.get_invalid_choice_message("d")
+    message = choice.get_invalid_choice_message("d", ctx=None)
     assert message == "'d' is not one of 'a', 'b', 'c'."