Fix inspect.type_info crashing on mixed-type Literals#1080
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type_info sorted a Literal's values with a plain sorted(), which raises TypeError on mixed-type literals such as Literal[1, None] or Literal[True, "yes"] since Python 3 forbids ordering across types. The encoder/decoder already support these literals, so type_info crashing on them is a contract violation. Sort by (type name, value) so same-type ordering is unchanged and mixed-type literals are grouped deterministically, with a try/except fallback. Also widen the LiteralType.values annotation to allow mixed/None members. Adds test_bool_literal and test_mixed_literal.
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Fixes #1018.
Problem
msgspec.inspect.type_infocrashes on mixed-typeLiterals:type_infodoestuple(sorted(args))on the literal's values, and Python 3 forbids<between values of different types. The encoder/decoder already handle these mixed-type literals fine (e.g.Literal[1, None]decodes1/nulland rejects2), sotype_infofailing on them is a contract violation.Fix
Sort the literal values with a
(type name, value)key instead. This keeps existing same-type ordering identical (Literal[3,1,2]→(1,2,3),Literal[True,False]→(False,True)) while grouping mixed-type literals deterministically rather than crashing, and atry/except TypeErrorfalls back to the original order as a safety net. TheLiteralType.valuesannotation is widened to allow mixed andNonemembers.Tests
Added
test_mixed_literal(Literal[1, None],Literal[True, "yes"]) andtest_bool_literal. Without the fixtest_mixed_literalraises theTypeError; with it the fulltest_inspect.py/test_schema.pypass (276 passed, 13 skipped).I'll add a
docs/changelog.mdentry referencing this PR number in a follow-up commit.Disclosure: I used AI assistance (Claude) to help locate and draft this fix, under my direction and review.