flake8 legacy api init_report does not return the instantiated Formatter

Again trying to fix https://github.com/asottile/cheetah_lint/issues/14

Related to #200 (closed)

Here's my current diff:

diff --git a/cheetah_lint/flake.py b/cheetah_lint/flake.py
index 6e204d8..5803530 100644
--- a/cheetah_lint/flake.py
+++ b/cheetah_lint/flake.py
@@ -8,10 +8,10 @@ import re
 import sys
 import tokenize
 
-import pycodestyle
 from Cheetah.compile import compile_source
 from Cheetah.legacy_compiler import LegacyCompiler
-from flake8.engine import get_style_guide
+from flake8.api.legacy import get_style_guide
+from flake8.api.legacy import formatter
 
 from cheetah_lint import five
 from cheetah_lint.util import read_file
@@ -83,13 +83,13 @@ def to_py(src):
     )
 
 
-class DataCollectingReporter(pycodestyle.BaseReport):
-    """A Reporter for pycodestyle/flake8 which simply collects data instead of
-    spewing to stdout.
+class DataCollectingFormatter(formatter.BaseFormatter):
+    """A formatter for flake8 which simply collects data instead of spewing to
+    stdout.
     """
 
     def __init__(self, *args, **kwargs):
-        super(DataCollectingReporter, self).__init__(*args, **kwargs)
+        super(DataCollectingFormatter, self).__init__(*args, **kwargs)
         self.data = []
 
     def error(self, line_number, offset, text, check):
@@ -264,10 +264,10 @@ def normalize_line_numbers(data, py_lines, cheetah_lines):
 def check_flake8(py_lines):
     # Apologies, flake8 doesn't quite make this elegant / easy
     checker = get_style_guide(select=SELECTED_ERRORS)
-    reporter = checker.init_report(DataCollectingReporter)
+    checker.init_report(DataCollectingFormatter)
     checker.input_file('<compiled cheetah>', py_lines)
     return filter_known_unused_assignments(filter_known_unused_imports(
-        reporter.data,
+        checker._application.formatter.data,
     ))

The last bit is pretty non-ideal (checker._application.formatter)

I think all init_report needs to do is return self._application.formatter, would a patch that does that be acceptable?

@asottile that'd be fine. I'm not sure what data you expect to be there though.

Also I'm sorry for the long delay in replying. I've been quite sick this last week and am only today starting to get back on my feet. I'm also truly sorry I missed cheetah-lint. I used code search across several sites to find projects using flake8's API and every example I could find (and I scanned through hundreds) was incredibly basic and (with the exception of imports) served by the current legacy re-implementation.

Added bug:confirmed label

Milestone changed to %3.x.y

Added component:legacy-api label

No big deal :) cheetah-lint is probably tiny / insignificant compared to the rest of the plugins and admittedly a bit weird.