Python: enumerate module-level functions and constants in DependencyTypes

[knutwannheden]

Motivation

• The DependencyTypes RPC (Add a DependencyTypes RPC to enumerate a dependency's public API #8360) enumerates a pip dependency's (or stdlib module's) public API so the Moderne CLI can serialize it into a shared per-coordinate type table. The enumeration harvested only classLiteral descriptors, so module-level functions (click.echo) and constants (os.sep) never reached the table. Parse-time attribution declares such references under a JavaType.Class named after the module (the declaring type of click.echo is a class with FQN click), but the enumeration never defined that class — so those references could never be resolved against the dependency's table and stayed shallow in every consumer, and the module-level half of a dependency's API was simply missing from the shared table.

Examples

For a distribution containing:

# toplib/__init__.py
GREETING = "hello"
TIMEOUT: float

def shout(text: str) -> str:
    return text.upper()

class Thing:
    def run(self) -> None: ...

the enumeration now defines toplib.Thing (as before) plus a toplib class whose methods include shout and whose members include GREETING and TIMEOUT. Re-exports are attributed to the re-exporting package: with click/__init__.py doing from click.utils import echo, the click module type carries echo as a method (under its binding name, so from x import echo as shout binds shout), while a re-exported class keeps its defining FQN.

Summary

• PythonTypeMapping.module_type(fqn) synthesizes a JavaType.Class for a module: public top-level functions as methods, public top-level constants (including annotation-only, stub-style declarations) as members, and re-exported bindings under their binding names. The public surface is __all__ when declared, else the non-underscore names. ty emits no descriptor for a file's own module and its registry cannot distinguish module-level functions from methods (both carry only moduleName), so the harvest walks the file's top-level AST and resolves each binding through the node index.
• _enumerate_artifact emits that module type per file; the first file defines a module's type, which the stub-first ordering makes the .pyi when one exists.
• _FUNCTION_KINDS replaces the six copies of the function-kind tuple, and _create_method_from_descriptor takes an optional name override for aliased re-exports.

Test plan

• New test: module-level function, constants (assigned and annotation-only), and class all enumerated; the class stays off the module type
• New test: re-exports surface on the package module type under their binding names (including aliases); re-exported classes keep their defining FQN; submodules get their own module type
• New test: underscore convention without __all__; __all__ as the public surface when declared
• pytest tests/rpc/test_dependency_types.py — 26 passed
• pytest tests/python/test_type_attribution.py — 151 passed, 4 skipped (type-attribution regression check for the shared type_mapping.py changes)