Fix 2.x open mode check; Add more tests

5 files changed, 43 insertions, 2 deletions

diff --git a/checkers/stdlib.py b/checkers/stdlib.py
index aafb970..6d4c89c 100644
--- a/checkers/stdlib.py
+++ b/checkers/stdlib.py
@@ -57,6 +57,8 @@ def _check_mode_str(mode):
         if writing or appending or creating and six.PY3:
             return False
         reading = True
+        if not six.PY3:
+            binary = True
     if text and binary:
         return False
     total = reading + writing + appending + (creating if six.PY3 else 0)
@@ -64,8 +66,12 @@ def _check_mode_str(mode):
         return False
     if not (reading or writing or appending or creating and six.PY3):
         return False
-    # 2.x constraints
+    # other 2.x constraints
     if not six.PY3:
+        if "U" in mode:
+            mode = mode.replace("U", "")
+            if "r" not in mode:
+                mode = "r" + mode
         return mode[0] in ("r", "w", "a", "U")
     return True
 
@@ -77,7 +83,8 @@ class StdlibChecker(BaseChecker):
     msgs = {
         'W1501': ('"%s" is not a valid mode for open.',
                   'bad-open-mode',
-                  'Python supports: r, w, a modes with b, +, and U options. '
+                  'Python supports: r, w, a[, x] modes with b, +, '
+                  'and U (only with r) options. '
                   'See http://docs.python.org/2/library/functions.html#open'),
         'W1502': ('Using datetime.time in a boolean context.',
                   'boolean-datetime',
diff --git a/test/functional/bad_open_mode.py b/test/functional/bad_open_mode.py
index 8659850..6b749de 100644
--- a/test/functional/bad_open_mode.py
+++ b/test/functional/bad_open_mode.py
@@ -17,3 +17,21 @@ open('foo.bar', 'r+b')
 open('foo.bar', 'r+')
 open('foo.bar', 'w+')
 open('foo.bar', 'xb')  # [bad-open-mode]
+open('foo.bar', 'rx')  # [bad-open-mode]
+open('foo.bar', 'Ur')
+open('foo.bar', 'rU')
+open('foo.bar', 'rUb')
+open('foo.bar', 'rUb+')
+open('foo.bar', 'rU+b')
+open('foo.bar', 'r+Ub')
+open('foo.bar', '+rUb')  # [bad-open-mode]
+open('foo.bar', 'ab+')
+open('foo.bar', 'a+b')
+open('foo.bar', 'aU')  # [bad-open-mode]
+open('foo.bar', 'U+b')
+open('foo.bar', '+Ub')
+open('foo.bar', 'b+U')
+open('foo.bar', 'Urb+')
+open('foo.bar', 'Ur+b')
+open('foo.bar', 'Ubr')  # [bad-open-mode]
+open('foo.bar', 'Ut')  # [bad-open-mode]
diff --git a/test/functional/bad_open_mode.txt b/test/functional/bad_open_mode.txt
index 775c979..b022286 100644
--- a/test/functional/bad_open_mode.txt
+++ b/test/functional/bad_open_mode.txt
@@ -7,3 +7,8 @@ bad-open-mode:13::"""Uwz"" is not a valid mode for open."
 bad-open-mode:14::"""br"" is not a valid mode for open."
 bad-open-mode:15::"""wU"" is not a valid mode for open."
 bad-open-mode:19::"""xb"" is not a valid mode for open."
+bad-open-mode:20::"""rx"" is not a valid mode for open."
+bad-open-mode:27::"""+rUb"" is not a valid mode for open."
+bad-open-mode:30::"""aU"" is not a valid mode for open."
+bad-open-mode:36::"""Ubr"" is not a valid mode for open."
+bad-open-mode:37::"""Ut"" is not a valid mode for open."
diff --git a/test/functional/bad_open_mode_py3.py b/test/functional/bad_open_mode_py3.py
index 7229eca..0812f5a 100644
--- a/test/functional/bad_open_mode_py3.py
+++ b/test/functional/bad_open_mode_py3.py
@@ -12,3 +12,12 @@ open(NAME, "rwx")  # [bad-open-mode]
 open(NAME, "rr")  # [bad-open-mode]

 open(NAME, "+")  # [bad-open-mode]

 open(NAME, "xw")  # [bad-open-mode]

+open(NAME, "ab+")

+open(NAME, "a+b")

+open(NAME, "+ab")

+open(NAME, "+rUb")

+open(NAME, "x+b")

+open(NAME, "Ua")  # [bad-open-mode]

+open(NAME, "Ur++")  # [bad-open-mode]

+open(NAME, "Ut")

+open(NAME, "Ubr")

diff --git a/test/functional/bad_open_mode_py3.txt b/test/functional/bad_open_mode_py3.txt
index ba3443c..0be0ea8 100644
--- a/test/functional/bad_open_mode_py3.txt
+++ b/test/functional/bad_open_mode_py3.txt
@@ -2,3 +2,5 @@ bad-open-mode:11::"""rwx"" is not a valid mode for open."
 bad-open-mode:12::"""rr"" is not a valid mode for open."

 bad-open-mode:13::"""+"" is not a valid mode for open."

 bad-open-mode:14::"""xw"" is not a valid mode for open."

+bad-open-mode:20::"""Ua"" is not a valid mode for open."

+bad-open-mode:21::"""Ur++"" is not a valid mode for open."