Don't write back stdin to stdout when --check is passed

[etc/vim.git] / black.py

diff --git a/black.py b/black.py
index 8a4eb05e5ad71cf04976c913a0f8bac6631bae7f..54044a5f564630289d7236e95fa0548d0049342b 100644 (file)
--- a/black.py
+++ b/black.py
@@ -102,7 +102,9 @@ def main(
         report = Report()
         try:
             if not p.is_file() and str(p) == '-':
-                changed = format_stdin_to_stdout(line_length=line_length, fast=fast)
+                changed = format_stdin_to_stdout(
+                    line_length=line_length, fast=fast, write_back=not check
+                )
             else:
                 changed = format_file_in_place(
                     p, line_length=line_length, fast=fast, write_back=not check
@@ -178,7 +180,9 @@ def format_file_in_place(
     return True
 
 
-def format_stdin_to_stdout(line_length: int, fast: bool) -> bool:
+def format_stdin_to_stdout(
+    line_length: int, fast: bool, write_back: bool = False
+) -> bool:
     """Format file on stdin and pipe output to stdout. Return True if changed."""
     contents = sys.stdin.read()
     try:
@@ -189,7 +193,8 @@ def format_stdin_to_stdout(line_length: int, fast: bool) -> bool:
         return False
 
     finally:
-        sys.stdout.write(contents)
+        if write_back:
+            sys.stdout.write(contents)
 
 
 def format_file_contents(
@@ -872,7 +877,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
         return DOUBLESPACE
 
     assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"
-    if t == token.COLON and p.type != syms.subscript:
+    if t == token.COLON and p.type not in {syms.subscript, syms.subscriptlist}:
         return NO
 
     prev = leaf.prev_sibling
@@ -905,7 +910,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
                 return NO
 
         elif prevp.type == token.COLON:
-            if prevp.parent and prevp.parent.type == syms.subscript:
+            if prevp.parent and prevp.parent.type in {syms.subscript, syms.sliceop}:
                 return NO
 
         elif prevp.parent and prevp.parent.type in {syms.factor, syms.star_expr}: