Wrap multiple context managers in parentheses when targeting Python 3.9+ (#3489)

[etc/vim.git] / src / black / nodes.py

diff --git a/src/black/nodes.py b/src/black/nodes.py
index 8f341ab35d63e6e9212489bc1f4bdaf8de04909e..a588077f4def9eb028da74463119f86f57d125f9 100644 (file)
--- a/src/black/nodes.py
+++ b/src/black/nodes.py
@@ -502,12 +502,14 @@ def container_of(leaf: Leaf) -> LN:
     return container
 
 
-def first_leaf_column(node: Node) -> Optional[int]:
-    """Returns the column of the first leaf child of a node."""
-    for child in node.children:
-        if isinstance(child, Leaf):
-            return child.column
-    return None
+def first_leaf_of(node: LN) -> Optional[Leaf]:
+    """Returns the first leaf of the node tree."""
+    if isinstance(node, Leaf):
+        return node
+    if node.children:
+        return first_leaf_of(node.children[0])
+    else:
+        return None
 
 
 def is_arith_like(node: LN) -> bool:
@@ -561,6 +563,17 @@ def is_one_tuple(node: LN) -> bool:
     )
 
 
+def is_tuple_containing_walrus(node: LN) -> bool:
+    """Return True if `node` holds a tuple that contains a walrus operator."""
+    if node.type != syms.atom:
+        return False
+    gexp = unwrap_singleton_parenthesis(node)
+    if gexp is None or gexp.type != syms.testlist_gexp:
+        return False
+
+    return any(child.type == syms.namedexpr_test for child in gexp.children)
+
+
 def is_one_sequence_between(
     opening: Leaf,
     closing: Leaf,
@@ -846,3 +859,15 @@ def is_string_token(nl: NL) -> TypeGuard[Leaf]:
 
 def is_number_token(nl: NL) -> TypeGuard[Leaf]:
     return nl.type == token.NUMBER
+
+
+def is_part_of_annotation(leaf: Leaf) -> bool:
+    """Returns whether this leaf is part of type annotations."""
+    ancestor = leaf.parent
+    while ancestor is not None:
+        if ancestor.prev_sibling and ancestor.prev_sibling.type == token.RARROW:
+            return True
+        if ancestor.parent and ancestor.parent.type == syms.tname:
+            return True
+        ancestor = ancestor.parent
+    return False