Extract formatting tests (#1785)

[etc/vim.git] / tests / util.py

diff --git a/tests/util.py b/tests/util.py
index 9c3d3cbc99d031e2a1d6cc556bd0b4ca0af878c0..da65ed0cc931ef00c71aab999c8b56fe750dd4fa 100644 (file)
--- a/tests/util.py
+++ b/tests/util.py
@@ -1,7 +1,10 @@
+import os
 import unittest
 from contextlib import contextmanager
 from pathlib import Path
-from typing import List, Tuple, Iterator
+from typing import List, Tuple, Iterator, Any
+import black
+from functools import partial
 
 THIS_DIR = Path(__file__).parent
 PROJECT_ROOT = THIS_DIR.parent
@@ -9,6 +12,39 @@ EMPTY_LINE = "# EMPTY LINE WITH WHITESPACE" + " (this comment will be removed)"
 DETERMINISTIC_HEADER = "[Deterministic header]"
 
 
+DEFAULT_MODE = black.FileMode(experimental_string_processing=True)
+ff = partial(black.format_file_in_place, mode=DEFAULT_MODE, fast=True)
+fs = partial(black.format_str, mode=DEFAULT_MODE)
+
+
+def dump_to_stderr(*output: str) -> str:
+    return "\n" + "\n".join(output) + "\n"
+
+
+class BlackBaseTestCase(unittest.TestCase):
+    maxDiff = None
+    _diffThreshold = 2 ** 20
+
+    def assertFormatEqual(self, expected: str, actual: str) -> None:
+        if actual != expected and not os.environ.get("SKIP_AST_PRINT"):
+            bdv: black.DebugVisitor[Any]
+            black.out("Expected tree:", fg="green")
+            try:
+                exp_node = black.lib2to3_parse(expected)
+                bdv = black.DebugVisitor()
+                list(bdv.visit(exp_node))
+            except Exception as ve:
+                black.err(str(ve))
+            black.out("Actual tree:", fg="red")
+            try:
+                exp_node = black.lib2to3_parse(actual)
+                bdv = black.DebugVisitor()
+                list(bdv.visit(exp_node))
+            except Exception as ve:
+                black.err(str(ve))
+        self.assertMultiLineEqual(expected, actual)
+
+
 @contextmanager
 def skip_if_exception(e: str) -> Iterator[None]:
     try:
@@ -24,11 +60,15 @@ def read_data(name: str, data: bool = True) -> Tuple[str, str]:
     """read_data('test_name') -> 'input', 'output'"""
     if not name.endswith((".py", ".pyi", ".out", ".diff")):
         name += ".py"
-    _input: List[str] = []
-    _output: List[str] = []
     base_dir = THIS_DIR / "data" if data else PROJECT_ROOT
-    with open(base_dir / name, "r", encoding="utf8") as test:
+    return read_data_from_file(base_dir / name)
+
+
+def read_data_from_file(file_name: Path) -> Tuple[str, str]:
+    with open(file_name, "r", encoding="utf8") as test:
         lines = test.readlines()
+    _input: List[str] = []
+    _output: List[str] = []
     result = _input
     for line in lines:
         line = line.replace(EMPTY_LINE, "")