fix: Fix building expressions (and string values) for yield and `yi…

…eld from` statements

src/griffe/agents/nodes/_values.py

@@ -291,8 +291,12 @@ def _extract_usub(node: ast.USub, **kwargs: Any) -> str:
 
 def _extract_yield(node: ast.Yield, **kwargs: Any) -> str:
  if node.value is None:
- return repr(None)
- return _extract(node.value, **kwargs)
+ return "yield"
+ return f"yield {_extract(node.value, **kwargs)}"
+
+
+def _extract_yield_from(node: ast.YieldFrom, **kwargs: Any) -> str:
+ return f"yield from {_extract(node.value, **kwargs)}"
 
 
 _node_map: dict[type, Callable[[Any], str]] = {
@@ -353,6 +357,7 @@ def _extract_yield(node: ast.Yield, **kwargs: Any) -> str:
  ast.UnaryOp: _extract_unaryop,
  ast.USub: _extract_usub,
  ast.Yield: _extract_yield,
+ ast.YieldFrom: _extract_yield_from,
 }
 
 # TODO: remove once Python 3.8 support is

src/griffe/expressions.py

@@ -724,6 +724,18 @@ def iterate(self, *, flat: bool = True) -> Iterator[str | Expr]: # noqa: D102
  yield from _yield(self.value, flat=flat)
 
 
+@dataclass(eq=True, **dataclass_opts)
+class ExprYieldFrom(Expr):
+ """Yield statements like `yield from a`."""
+
+ value: str | Expr
+ """Yielded-from value."""
+
+ def iterate(self, *, flat: bool = True) -> Iterator[str | Expr]:
+ yield "yield from "
+ yield from _yield(self.value, flat=flat)
+
+
 _unary_op_map = {
  ast.Invert: "~",
  ast.Not: "not ",
@@ -1002,6 +1014,10 @@ def _build_yield(node: ast.Yield, parent: Module | Class, **kwargs: Any) -> Expr
  return ExprYield(None if node.value is None else _build(node.value, parent, **kwargs))
 
 
+def _build_yield_from(node: ast.YieldFrom, parent: Module | Class, **kwargs: Any) -> Expr:
+ return ExprYieldFrom(_build(node.value, parent, **kwargs))
+
+
 _node_map: dict[type, Callable[[Any, Module | Class], Expr]] = {
  ast.Attribute: _build_attribute,
  ast.BinOp: _build_binop,
@@ -1030,6 +1046,7 @@ def _build_yield(node: ast.Yield, parent: Module | Class, **kwargs: Any) -> Expr
  ast.Tuple: _build_tuple,
  ast.UnaryOp: _build_unaryop,
  ast.Yield: _build_yield,
+ ast.YieldFrom: _build_yield_from,
 }
 
 # TODO: remove once Python 3.8 support is dropped

tests/test_nodes.py

@@ -69,6 +69,10 @@
  "{a, b, c}",
  "{a: b, c: d}",
  "[a, b, c]",
+ # yields
+ "yield",
+ "yield a",
+ "yield from a",
 ]