add preview option support for blackd (#3217)

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

diff --git a/src/black/output.py b/src/black/output.py
index 6831524090d9a82107146bf8a89ee815fa58d1c9..f4c17f28ea418d363f9b388e3770c208ca26b1b1 100644 (file)
--- a/src/black/output.py
+++ b/src/black/output.py
@@ -3,13 +3,15 @@
 The double calls are for patching purposes in tests.
 """
 
-from typing import Any, Optional
-from mypy_extensions import mypyc_attr
+import json
 import tempfile
+from typing import Any, Optional
 
 from click import echo, style
+from mypy_extensions import mypyc_attr
 
 
+@mypyc_attr(patchable=True)
 def _out(message: Optional[str] = None, nl: bool = True, **styles: Any) -> None:
     if message is not None:
         if "bold" not in styles:
@@ -18,6 +20,7 @@ def _out(message: Optional[str] = None, nl: bool = True, **styles: Any) -> None:
     echo(message, nl=nl, err=True)
 
 
+@mypyc_attr(patchable=True)
 def _err(message: Optional[str] = None, nl: bool = True, **styles: Any) -> None:
     if message is not None:
         if "fg" not in styles:
@@ -26,6 +29,7 @@ def _err(message: Optional[str] = None, nl: bool = True, **styles: Any) -> None:
     echo(message, nl=nl, err=True)
 
 
+@mypyc_attr(patchable=True)
 def out(message: Optional[str] = None, nl: bool = True, **styles: Any) -> None:
     _out(message, nl=nl, **styles)
 
@@ -34,18 +38,36 @@ def err(message: Optional[str] = None, nl: bool = True, **styles: Any) -> None:
     _err(message, nl=nl, **styles)
 
 
+def ipynb_diff(a: str, b: str, a_name: str, b_name: str) -> str:
+    """Return a unified diff string between each cell in notebooks `a` and `b`."""
+    a_nb = json.loads(a)
+    b_nb = json.loads(b)
+    diff_lines = [
+        diff(
+            "".join(a_nb["cells"][cell_number]["source"]) + "\n",
+            "".join(b_nb["cells"][cell_number]["source"]) + "\n",
+            f"{a_name}:cell_{cell_number}",
+            f"{b_name}:cell_{cell_number}",
+        )
+        for cell_number, cell in enumerate(a_nb["cells"])
+        if cell["cell_type"] == "code"
+    ]
+    return "".join(diff_lines)
+
+
 def diff(a: str, b: str, a_name: str, b_name: str) -> str:
     """Return a unified diff string between strings `a` and `b`."""
     import difflib
 
-    a_lines = [line for line in a.splitlines(keepends=True)]
-    b_lines = [line for line in b.splitlines(keepends=True)]
+    a_lines = a.splitlines(keepends=True)
+    b_lines = b.splitlines(keepends=True)
     diff_lines = []
     for line in difflib.unified_diff(
         a_lines, b_lines, fromfile=a_name, tofile=b_name, n=5
     ):
         # Work around https://bugs.python.org/issue2142
-        # See https://www.gnu.org/software/diffutils/manual/html_node/Incomplete-Lines.html
+        # See:
+        # https://www.gnu.org/software/diffutils/manual/html_node/Incomplete-Lines.html
         if line[-1] == "\n":
             diff_lines.append(line)
         else:
@@ -59,7 +81,7 @@ def color_diff(contents: str) -> str:
     lines = contents.split("\n")
     for i, line in enumerate(lines):
         if line.startswith("+++") or line.startswith("---"):
-            line = "\033[1;37m" + line + "\033[0m"  # bold white, reset
+            line = "\033[1m" + line + "\033[0m"  # bold, reset
         elif line.startswith("@@"):
             line = "\033[36m" + line + "\033[0m"  # cyan, reset
         elif line.startswith("+"):