prepare release 2021.11b1 (#2622)

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

diff --git a/src/black/handle_ipynb_magics.py b/src/black/handle_ipynb_magics.py
index ad93c444efc98a7dfd2c12b54dc4cd834bb08b2f..2fe6739209dd626597a43011b8bc576ae203cc9a 100644 (file)
--- a/src/black/handle_ipynb_magics.py
+++ b/src/black/handle_ipynb_magics.py
@@ -1,15 +1,19 @@
 """Functions to process IPython magics with."""
+
 from functools import lru_cache
 import dataclasses
 import ast
-from typing import Dict
+from typing import Dict, List, Tuple, Optional
 
 import secrets
-from typing import List, Tuple
+import sys
 import collections
 
-from typing import Optional
-from typing_extensions import TypeGuard
+if sys.version_info >= (3, 10):
+    from typing import TypeGuard
+else:
+    from typing_extensions import TypeGuard
+
 from black.report import NothingChanged
 from black.output import out
 
@@ -35,20 +39,21 @@ TOKENS_TO_IGNORE = frozenset(
 )
 NON_PYTHON_CELL_MAGICS = frozenset(
     (
-        "%%bash",
-        "%%html",
-        "%%javascript",
-        "%%js",
-        "%%latex",
-        "%%markdown",
-        "%%perl",
-        "%%ruby",
-        "%%script",
-        "%%sh",
-        "%%svg",
-        "%%writefile",
+        "bash",
+        "html",
+        "javascript",
+        "js",
+        "latex",
+        "markdown",
+        "perl",
+        "ruby",
+        "script",
+        "sh",
+        "svg",
+        "writefile",
     )
 )
+TOKEN_HEX = secrets.token_hex
 
 
 @dataclasses.dataclass(frozen=True)
@@ -184,10 +189,10 @@ def get_token(src: str, magic: str) -> str:
     """
     assert magic
     nbytes = max(len(magic) // 2 - 1, 1)
-    token = secrets.token_hex(nbytes)
+    token = TOKEN_HEX(nbytes)
     counter = 0
-    while token in src:  # pragma: nocover
-        token = secrets.token_hex(nbytes)
+    while token in src:
+        token = TOKEN_HEX(nbytes)
         counter += 1
         if counter > 100:
             raise AssertionError(
@@ -225,10 +230,11 @@ def replace_cell_magics(src: str) -> Tuple[str, List[Replacement]]:
     cell_magic_finder.visit(tree)
     if cell_magic_finder.cell_magic is None:
         return src, replacements
-    if cell_magic_finder.cell_magic.header.split()[0] in NON_PYTHON_CELL_MAGICS:
+    if cell_magic_finder.cell_magic.name in NON_PYTHON_CELL_MAGICS:
         raise NothingChanged
-    mask = get_token(src, cell_magic_finder.cell_magic.header)
-    replacements.append(Replacement(mask=mask, src=cell_magic_finder.cell_magic.header))
+    header = cell_magic_finder.cell_magic.header
+    mask = get_token(src, header)
+    replacements.append(Replacement(mask=mask, src=header))
     return f"{mask}\n{cell_magic_finder.cell_magic.body}", replacements
 
 
@@ -306,13 +312,28 @@ def _is_ipython_magic(node: ast.expr) -> TypeGuard[ast.Attribute]:
     )
 
 
+def _get_str_args(args: List[ast.expr]) -> List[str]:
+    str_args = []
+    for arg in args:
+        assert isinstance(arg, ast.Str)
+        str_args.append(arg.s)
+    return str_args
+
+
 @dataclasses.dataclass(frozen=True)
 class CellMagic:
-    header: str
+    name: str
+    params: Optional[str]
     body: str
 
+    @property
+    def header(self) -> str:
+        if self.params:
+            return f"%%{self.name} {self.params}"
+        return f"%%{self.name}"
+
 
-@dataclasses.dataclass
+# ast.NodeVisitor + dataclass = breakage under mypyc.
 class CellMagicFinder(ast.NodeVisitor):
     """Find cell magics.
 
@@ -331,7 +352,8 @@ class CellMagicFinder(ast.NodeVisitor):
     and we look for instances of the latter.
     """
 
-    cell_magic: Optional[CellMagic] = None
+    def __init__(self, cell_magic: Optional[CellMagic] = None) -> None:
+        self.cell_magic = cell_magic
 
     def visit_Expr(self, node: ast.Expr) -> None:
         """Find cell magic, extract header and body."""
@@ -340,14 +362,8 @@ class CellMagicFinder(ast.NodeVisitor):
             and _is_ipython_magic(node.value.func)
             and node.value.func.attr == "run_cell_magic"
         ):
-            args = []
-            for arg in node.value.args:
-                assert isinstance(arg, ast.Str)
-                args.append(arg.s)
-            header = f"%%{args[0]}"
-            if args[1]:
-                header += f" {args[1]}"
-            self.cell_magic = CellMagic(header=header, body=args[2])
+            args = _get_str_args(node.value.args)
+            self.cell_magic = CellMagic(name=args[0], params=args[1], body=args[2])
         self.generic_visit(node)
 
 
@@ -357,7 +373,8 @@ class OffsetAndMagic:
     magic: str
 
 
-@dataclasses.dataclass
+# Unsurprisingly, subclassing ast.NodeVisitor means we can't use dataclasses here
+# as mypyc will generate broken code.
 class MagicFinder(ast.NodeVisitor):
     """Visit cell to look for get_ipython calls.
 
@@ -377,9 +394,8 @@ class MagicFinder(ast.NodeVisitor):
     types of magics).
     """
 
-    magics: Dict[int, List[OffsetAndMagic]] = dataclasses.field(
-        default_factory=lambda: collections.defaultdict(list)
-    )
+    def __init__(self) -> None:
+        self.magics: Dict[int, List[OffsetAndMagic]] = collections.defaultdict(list)
 
     def visit_Assign(self, node: ast.Assign) -> None:
         """Look for system assign magics.
@@ -399,12 +415,8 @@ class MagicFinder(ast.NodeVisitor):
             and _is_ipython_magic(node.value.func)
             and node.value.func.attr == "getoutput"
         ):
-            args = []
-            for arg in node.value.args:
-                assert isinstance(arg, ast.Str)
-                args.append(arg.s)
-            assert args
-            src = f"!{args[0]}"
+            (arg,) = _get_str_args(node.value.args)
+            src = f"!{arg}"
             self.magics[node.value.lineno].append(
                 OffsetAndMagic(node.value.col_offset, src)
             )
@@ -430,11 +442,7 @@ class MagicFinder(ast.NodeVisitor):
         and we look for instances of any of the latter.
         """
         if isinstance(node.value, ast.Call) and _is_ipython_magic(node.value.func):
-            args = []
-            for arg in node.value.args:
-                assert isinstance(arg, ast.Str)
-                args.append(arg.s)
-            assert args
+            args = _get_str_args(node.value.args)
             if node.value.func.attr == "run_line_magic":
                 if args[0] == "pinfo":
                     src = f"?{args[1]}"