Assign missing codes to PyFlakes messages

Some PyFlakes messages weren't covered by unique messages, making them
impossible to select/ignore. This is now fixed.

To ensure we don't regress in the future, a test has been added that fails if
there's any uncovered messages.

4 files changed, 85 insertions, 18 deletions

diff --git a/docs/source/release-notes/3.3.0.rst b/docs/source/release-notes/3.3.0.rst
index ed9f171..fc7c2f4 100644
--- a/docs/source/release-notes/3.3.0.rst
+++ b/docs/source/release-notes/3.3.0.rst
@@ -6,6 +6,9 @@ You can view the `3.3.0 milestone`_ on GitLab for more details.
 - Fix problem where hooks should only check \*.py files. (See also
   `GitLab#268`_)
 
+- Added unique error codes for all missing PyFlakes messages (14 new
+  codes, see all :ref:`Error / Violation Codes <error_codes>`)
+
 .. links
 .. _3.3.0 milestone:
     https://gitlab.com/pycqa/flake8/milestones/16
diff --git a/docs/source/user/error-codes.rst b/docs/source/user/error-codes.rst
index 8bff640..dbaf35e 100644
--- a/docs/source/user/error-codes.rst
+++ b/docs/source/user/error-codes.rst
@@ -1,3 +1,5 @@
+.. _error_codes:
+
 =========================
  Error / Violation Codes
 =========================
@@ -22,6 +24,36 @@ generates its own :term:`error code`\ s for ``pyflakes``:
 +------+---------------------------------------------------------------------+
 | F405 | ``name`` may be undefined, or defined from star imports: ``module`` |
 +------+---------------------------------------------------------------------+
+| F406 | 'from ``module`` import \*' only allowed at module level            |
++------+---------------------------------------------------------------------+
+| F407 | an undefined ``__future__`` feature name was imported               |
++------+---------------------------------------------------------------------+
++------+---------------------------------------------------------------------+
+| F601 | dictionary key ``name`` repeated with different values              |
++------+---------------------------------------------------------------------+
+| F602 | dictionary key variable ``name`` repeated with different values     |
++------+---------------------------------------------------------------------+
+| F621 | too many expressions in an assignment with star-unpacking           |
++------+---------------------------------------------------------------------+
+| F622 | two or more starred expressions in an assignment ``(a, *b, *c = d)``|
++------+---------------------------------------------------------------------+
+| F631 | assertion test is a tuple, which are always ``True``                |
++------+---------------------------------------------------------------------+
++------+---------------------------------------------------------------------+
+| F701 | a ``break`` statement outside of a ``while`` or ``for`` loop        |
++------+---------------------------------------------------------------------+
+| F702 | a ``continue`` statement outside of a ``while`` or ``for`` loop     |
++------+---------------------------------------------------------------------+
+| F703 | a ``continue`` statement in a ``finally`` block in a loop           |
++------+---------------------------------------------------------------------+
+| F704 | a ``yield`` or ``yield from`` statement outside of a function       |
++------+---------------------------------------------------------------------+
+| F705 | a ``return`` statement with arguments inside a generator            |
++------+---------------------------------------------------------------------+
+| F706 | a ``return`` statement outside of a function/method                 |
++------+---------------------------------------------------------------------+
+| F707 | an ``except:`` block as not the last exception handler              |
++------+---------------------------------------------------------------------+
 +------+---------------------------------------------------------------------+
 | F811 | redefinition of unused ``name`` from line ``N``                     |
 +------+---------------------------------------------------------------------+
@@ -29,7 +61,7 @@ generates its own :term:`error code`\ s for ``pyflakes``:
 +------+---------------------------------------------------------------------+
 | F821 | undefined name ``name``                                             |
 +------+---------------------------------------------------------------------+
-| F822 | undefined name ``name`` in __all__                                  |
+| F822 | undefined name ``name`` in ``__all__``                              |
 +------+---------------------------------------------------------------------+
 | F823 | local variable ``name`` ... referenced before assignment            |
 +------+---------------------------------------------------------------------+
diff --git a/src/flake8/plugins/pyflakes.py b/src/flake8/plugins/pyflakes.py
index ca22302..65a31d0 100644
--- a/src/flake8/plugins/pyflakes.py
+++ b/src/flake8/plugins/pyflakes.py
@@ -17,27 +17,44 @@ import pyflakes.checker
 from flake8 import utils
 
 
+FLAKE8_PYFLAKES_CODES = dict([line.split()[::-1] for line in (
+    'F401 UnusedImport',
+    'F402 ImportShadowedByLoopVar',
+    'F403 ImportStarUsed',
+    'F404 LateFutureImport',
+    'F405 ImportStarUsage',
+    'F406 ImportStarNotPermitted',
+    'F407 FutureFeatureNotDefined',
+    'F601 MultiValueRepeatedKeyLiteral',
+    'F602 MultiValueRepeatedKeyVariable',
+    'F621 TooManyExpressionsInStarredAssignment',
+    'F622 TwoStarredExpressions',
+    'F631 AssertTuple',
+    'F701 BreakOutsideLoop',
+    'F702 ContinueOutsideLoop',
+    'F703 ContinueInFinally',
+    'F704 YieldOutsideFunction',
+    'F705 ReturnWithArgsInsideGenerator',
+    'F706 ReturnOutsideFunction',
+    'F707 DefaultExceptNotLast',
+    'F721 DoctestSyntaxError',
+    'F811 RedefinedWhileUnused',
+    'F812 RedefinedInListComp',
+    'F821 UndefinedName',
+    'F822 UndefinedExport',
+    'F823 UndefinedLocal',
+    'F831 DuplicateArgument',
+    'F841 UnusedVariable',
+)])
+
+
 def patch_pyflakes():
     """Add error codes to Pyflakes messages."""
-    codes = dict([line.split()[::-1] for line in (
-        'F401 UnusedImport',
-        'F402 ImportShadowedByLoopVar',
-        'F403 ImportStarUsed',
-        'F404 LateFutureImport',
-        'F405 ImportStarUsage',
-        'F810 Redefined',
-        'F811 RedefinedWhileUnused',
-        'F812 RedefinedInListComp',
-        'F821 UndefinedName',
-        'F822 UndefinedExport',
-        'F823 UndefinedLocal',
-        'F831 DuplicateArgument',
-        'F841 UnusedVariable',
-    )])
-
     for name, obj in vars(pyflakes.messages).items():
         if name[0].isupper() and obj.message:
-            obj.flake8_msg = '%s %s' % (codes.get(name, 'F999'), obj.message)
+            obj.flake8_msg = '%s %s' % (
+                FLAKE8_PYFLAKES_CODES.get(name, 'F999'), obj.message
+            )
 
 
 patch_pyflakes()
diff --git a/tests/unit/test_pyflakes_codes.py b/tests/unit/test_pyflakes_codes.py
new file mode 100644
index 0000000..837e971
--- /dev/null
+++ b/tests/unit/test_pyflakes_codes.py
@@ -0,0 +1,15 @@
+"""Tests of pyflakes monkey patches."""
+
+import pyflakes
+
+from flake8.plugins import pyflakes as pyflakes_shim
+
+
+def test_all_pyflakes_messages_have_flake8_codes_assigned():
+    """Verify all PyFlakes messages have error codes assigned."""
+    messages = {
+        name
+        for name, obj in vars(pyflakes.messages).items()
+        if name[0].isupper() and obj.message
+    }
+    assert messages == set(pyflakes_shim.FLAKE8_PYFLAKES_CODES)