From 207c979761ba07646e44ba9d22cbf242fc9dc8d4 Mon Sep 17 00:00:00 2001
From: ShaharNaveh <50263213+ShaharNaveh@users.noreply.github.com>
Date: Fri, 13 Feb 2026 13:33:29 +0200
Subject: [PATCH] Add `test_flufl.py`

---
 Lib/test/test_flufl.py | 69 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 Lib/test/test_flufl.py

diff --git a/Lib/test/test_flufl.py b/Lib/test/test_flufl.py
new file mode 100644
index 000000000..bd6267d45
--- /dev/null
+++ b/Lib/test/test_flufl.py
@@ -0,0 +1,69 @@
+import __future__
+import unittest
+
+
+class FLUFLTests(unittest.TestCase):
+
+    @unittest.expectedFailure  # TODO: RUSTPYTHON
+    def test_barry_as_bdfl(self):
+        code = "from __future__ import barry_as_FLUFL\n2 {0} 3"
+        compile(code.format('<>'), '<BDFL test>', 'exec',
+                __future__.CO_FUTURE_BARRY_AS_BDFL)
+        with self.assertRaises(SyntaxError) as cm:
+            compile(code.format('!='), '<FLUFL test>', 'exec',
+                    __future__.CO_FUTURE_BARRY_AS_BDFL)
+        self.assertRegex(str(cm.exception),
+                         "with Barry as BDFL, use '<>' instead of '!='")
+        self.assertIn('2 != 3', cm.exception.text)
+        self.assertEqual(cm.exception.filename, '<FLUFL test>')
+
+        self.assertEqual(cm.exception.lineno, 2)
+        # The old parser reports the end of the token and the new
+        # parser reports the start of the token
+        self.assertEqual(cm.exception.offset, 3)
+
+    @unittest.expectedFailure  # TODO: RUSTPYTHON
+    def test_guido_as_bdfl(self):
+        code = '2 {0} 3'
+        compile(code.format('!='), '<BDFL test>', 'exec')
+        with self.assertRaises(SyntaxError) as cm:
+            compile(code.format('<>'), '<FLUFL test>', 'exec')
+        self.assertRegex(str(cm.exception), "invalid syntax")
+        self.assertIn('2 <> 3', cm.exception.text)
+        self.assertEqual(cm.exception.filename, '<FLUFL test>')
+        self.assertEqual(cm.exception.lineno, 1)
+        # The old parser reports the end of the token and the new
+        # parser reports the start of the token
+        self.assertEqual(cm.exception.offset, 3)
+
+    @unittest.expectedFailure  # TODO: RUSTPYTHON
+    def test_barry_as_bdfl_look_ma_with_no_compiler_flags(self):
+        # Check that the future import is handled by the parser
+        # even if the compiler flags are not passed.
+        code = "from __future__ import barry_as_FLUFL;2 {0} 3"
+        compile(code.format('<>'), '<BDFL test>', 'exec')
+        with self.assertRaises(SyntaxError) as cm:
+            compile(code.format('!='), '<FLUFL test>', 'exec')
+        self.assertRegex(str(cm.exception), "with Barry as BDFL, use '<>' instead of '!='")
+        self.assertIn('2 != 3', cm.exception.text)
+        self.assertEqual(cm.exception.filename, '<FLUFL test>')
+        self.assertEqual(cm.exception.lineno, 1)
+        self.assertEqual(cm.exception.offset, len(code) - 4)
+
+    @unittest.expectedFailure  # TODO: RUSTPYTHON
+    def test_barry_as_bdfl_relative_import(self):
+        code = "from .__future__ import barry_as_FLUFL;2 {0} 3"
+        compile(code.format('!='), '<FLUFL test>', 'exec')
+        with self.assertRaises(SyntaxError) as cm:
+            compile(code.format('<>'), '<BDFL test>', 'exec')
+        self.assertRegex(str(cm.exception), "<BDFL test>")
+        self.assertIn('2 <> 3', cm.exception.text)
+        self.assertEqual(cm.exception.filename, '<BDFL test>')
+        self.assertEqual(cm.exception.lineno, 1)
+        self.assertEqual(cm.exception.offset, len(code) - 4)
+
+
+
+
+if __name__ == '__main__':
+    unittest.main()