[py23_test] test py23.open for piping binary data through stdin/stdout

Lib/fontTools/misc/py23_test.py

@@ -0,0 +1,66 @@
+from __future__ import print_function, division, absolute_import
+from fontTools.misc.py23 import tobytes
+from fontTools.misc.textTools import deHexStr
+import filecmp
+import tempfile
+from subprocess import check_call
+import sys
+import os
+import unittest
+
+
+PIPE_SCRIPT = """\
+import sys
+binary_stdin = open(sys.stdin.fileno(), mode='rb', closefd=False)
+binary_stdout = open(sys.stdout.fileno(), mode='wb', closefd=False)
+binary_stdout.write(binary_stdin.read())
+"""
+
+# the string contains a mix of line endings, plus the Win "EOF" charater (0x1A)
+# 'hello\rworld\r\n\x1a\r\n'
+TEST_BIN_DATA = deHexStr(
+	"68 65 6c 6c 6f 0d 77 6f 72 6c 64 0d 0a 1a 0d 0a"
+)
+
+class OpenFuncWrapperTest(unittest.TestCase):
+
+	@staticmethod
+	def make_temp(data):
+		with tempfile.NamedTemporaryFile(delete=False) as f:
+			f.write(tobytes(data))
+		return f.name
+
+	def diff_piped(self, data, import_statement):
+		script = self.make_temp("\n".join([import_statement, PIPE_SCRIPT]))
+		datafile = self.make_temp(data)
+		try:
+			with open(datafile, 'rb') as infile, \
+					tempfile.NamedTemporaryFile(delete=False) as outfile:
+				check_call(
+					[sys.executable, script], stdin=infile, stdout=outfile)
+			result = not filecmp.cmp(infile.name, outfile.name, shallow=False)
+		finally:
+			os.remove(script)
+			os.remove(datafile)
+			os.remove(outfile.name)
+		return result
+
+	def test_binary_pipe_py23_open_wrapper(self):
+		if self.diff_piped(
+				TEST_BIN_DATA, "from fontTools.misc.py23 import open"):
+			self.fail("Input and output data differ!")
+
+	def test_binary_pipe_built_in_io_open(self):
+		if sys.version_info.major < 3 and sys.platform == 'win32':
+			# On Windows Python 2.x, the piped input and output data are
+			# expected to be different when using io.open, because of issue
+			# https://bugs.python.org/issue10841.
+			expected = True
+		else:
+			expected = False
+		result = self.diff_piped(TEST_BIN_DATA, "from io import open")
+		self.assertEqual(result, expected)
+
+
+if __name__ == "__main__":
+	unittest.main()