Add Literal support for docstrings (#17441)

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(Explain how this PR changes mypy.)

Updates the is_valid_type regex to include quotes and .

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mypy/stubdoc.py

@@ -20,7 +20,7 @@
 Sig: _TypeAlias = Tuple[str, str]
 
 
-_TYPE_RE: Final = re.compile(r"^[a-zA-Z_][\w\[\], ]*(\.[a-zA-Z_][\w\[\], ]*)*$")
+_TYPE_RE: Final = re.compile(r"^[a-zA-Z_][\w\[\], .\"\']*(\.[a-zA-Z_][\w\[\], ]*)*$")
 _ARG_NAME_RE: Final = re.compile(r"\**[A-Za-z_][A-Za-z0-9_]*$")
 
 

mypy/stubgenc.py

@@ -252,6 +252,7 @@ def __init__(
                         "Iterable",
                         "Iterator",
                         "List",
+                        "Literal",
                         "NamedTuple",
                         "Optional",
                         "Tuple",

mypy/test/teststubgen.py

@@ -1357,6 +1357,17 @@ def test_is_valid_type(self) -> None:
         assert is_valid_type("List[int]")
         assert is_valid_type("Dict[str, int]")
         assert is_valid_type("None")
+        assert is_valid_type("Literal[26]")
+        assert is_valid_type("Literal[0x1A]")
+        assert is_valid_type('Literal["hello world"]')
+        assert is_valid_type('Literal[b"hello world"]')
+        assert is_valid_type('Literal[u"hello world"]')
+        assert is_valid_type("Literal[True]")
+        assert is_valid_type("Literal[Color.RED]")
+        assert is_valid_type("Literal[None]")
+        assert is_valid_type(
+            'Literal[26, 0x1A, "hello world", b"hello world", u"hello world", True, Color.RED, None]'
+        )
         assert not is_valid_type("foo-bar")
         assert not is_valid_type("x->y")
         assert not is_valid_type("True")