Document shebang comment behaviour (#3787)

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

diff --git a/src/black/nodes.py b/src/black/nodes.py
index 45070909df466c2fce7746788e6ac762c5a091a7..45423b2596be6946b203151c9a93200e25eb92df 100644 (file)
--- a/src/black/nodes.py
+++ b/src/black/nodes.py
@@ -3,12 +3,8 @@ blib2to3 Node/Leaf transformation-related utility functions.
 """
 
 import sys
-from typing import Generic, Iterator, List, Optional, Set, Tuple, TypeVar, Union
+from typing import Final, Generic, Iterator, List, Optional, Set, Tuple, TypeVar, Union
 
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
 if sys.version_info >= (3, 10):
     from typing import TypeGuard
 else:
@@ -718,6 +714,11 @@ def is_multiline_string(leaf: Leaf) -> bool:
 
 def is_stub_suite(node: Node) -> bool:
     """Return True if `node` is a suite with a stub body."""
+
+    # If there is a comment, we want to keep it.
+    if node.prefix.strip():
+        return False
+
     if (
         len(node.children) != 4
         or node.children[0].type != token.NEWLINE
@@ -726,6 +727,9 @@ def is_stub_suite(node: Node) -> bool:
     ):
         return False
 
+    if node.children[3].prefix.strip():
+        return False
+
     return is_stub_body(node.children[2])
 
 
@@ -739,7 +743,8 @@ def is_stub_body(node: LN) -> bool:
 
     child = node.children[0]
     return (
-        child.type == syms.atom
+        not child.prefix.strip()
+        and child.type == syms.atom
         and len(child.children) == 3
         and all(leaf == Leaf(token.DOT, ".") for leaf in child.children)
     )
@@ -816,12 +821,27 @@ def is_async_stmt_or_funcdef(leaf: Leaf) -> bool:
     )
 
 
-def is_type_comment(leaf: Leaf, suffix: str = "") -> bool:
-    """Return True if the given leaf is a special comment.
-    Only returns true for type comments for now."""
+def is_type_comment(leaf: Leaf) -> bool:
+    """Return True if the given leaf is a type comment. This function should only
+    be used for general type comments (excluding ignore annotations, which should
+    use `is_type_ignore_comment`). Note that general type comments are no longer
+    used in modern version of Python, this function may be deprecated in the future."""
     t = leaf.type
     v = leaf.value
-    return t in {token.COMMENT, STANDALONE_COMMENT} and v.startswith("# type:" + suffix)
+    return t in {token.COMMENT, STANDALONE_COMMENT} and v.startswith("# type:")
+
+
+def is_type_ignore_comment(leaf: Leaf) -> bool:
+    """Return True if the given leaf is a type comment with ignore annotation."""
+    t = leaf.type
+    v = leaf.value
+    return t in {token.COMMENT, STANDALONE_COMMENT} and is_type_ignore_comment_string(v)
+
+
+def is_type_ignore_comment_string(value: str) -> bool:
+    """Return True if the given string match with type comment with
+    ignore annotation."""
+    return value.startswith("# type: ignore")
 
 
 def wrap_in_parentheses(parent: Node, child: LN, *, visible: bool = True) -> None: