Make _LiteralEvalVisitor public (#129)

AlexWaygood · web-flow · commit 703d067be4e6 · 2025-07-23T07:14:43.000-07:00
diff --git a/typeshed_client/__init__.py b/typeshed_client/__init__.py
@@ -11,6 +11,7 @@
 )
 from .parser import (
     ImportedName,
+    LiteralEvalVisitor,
     NameDict,
     NameInfo,
     OverloadedName,
@@ -25,6 +26,7 @@
 __all__ = [
     "ImportedInfo",
     "ImportedName",
+    "LiteralEvalVisitor",
     "ModulePath",
     "NameDict",
     "NameInfo",
diff --git a/typeshed_client/parser.py b/typeshed_client/parser.py
@@ -305,7 +305,7 @@ def visit_If(self, node: ast.If) -> Iterable[NameInfo]:
                 yield from self.visit(stmt)
 
     def _visit_condition(self, expr: ast.expr) -> Optional[bool]:
-        visitor = _LiteralEvalVisitor(self.ctx, self.file_path)
+        visitor = LiteralEvalVisitor(self.ctx, self.file_path)
         try:
             value = visitor.visit(expr)
         except InvalidStub:
@@ -430,7 +430,17 @@ def generic_visit(self, node: ast.AST) -> Iterable[NameInfo]:
         raise InvalidStub(f"Cannot handle node {ast.dump(node)}", self.file_path)
 
 
-class _LiteralEvalVisitor(ast.NodeVisitor):
+class LiteralEvalVisitor(ast.NodeVisitor):
+    """Visitor to evaluate the truthiness of a ``test`` expression in an ``ast.Compare`` node.
+
+    ``LiteralEvalVisitor(ctx, path).visit(node)`` will return ``True`` if ``node`` is an
+    expression that can be statically determined to always be ``True``, ``False`` if it can
+    be statically determined to always be ``False``, and ``None`` if its truthiness cannot
+    be determined statically. For example, if passed an AST node representing the expression
+    ``sys.platform == "linux"``, it will return ``True`` if ``ctx.platform`` is equal to
+    ``"linux"``, otherwise ``False``.
+    """
+
     def __init__(self, ctx: SearchContext, file_path: Optional[Path]) -> None:
         self.ctx = ctx
         self.file_path = file_path
