Add configurable flake8 executable (#821)

pyls/plugins/flake8_lint.py

@@ -41,25 +41,28 @@ def pyls_lint(workspace, document):
         log.debug("using flake8 with config: %s", opts['config'])
 
     # Call the flake8 utility then parse diagnostics from stdout
+    flake8_executable = settings.get('executable', 'flake8')
+
     args = build_args(opts, document.path)
-    output = run_flake8(args)
+    output = run_flake8(flake8_executable, args)
     return parse_stdout(document, output)
 
 
-def run_flake8(args):
+def run_flake8(flake8_executable, args):
     """Run flake8 with the provided arguments, logs errors
     from stderr if any.
     """
     # a quick temporary fix to deal with Atom
     args = [(i if not i.startswith('--ignore=') else FIX_IGNORES_RE.sub('', i))
             for i in args if i is not None]
-    log.debug("Calling flake8 with args: '%s'", args)
+
+    log.debug("Calling %s with args: '%s'", flake8_executable, args)
     try:
-        cmd = ['flake8']
+        cmd = [flake8_executable]
         cmd.extend(args)
         p = Popen(cmd, stdout=PIPE, stderr=PIPE)
     except IOError:
-        log.debug("Can't execute flake8. Trying with 'python -m flake8'")
+        log.debug("Can't execute %s. Trying with 'python -m flake8'", flake8_executable)
         cmd = ['python', '-m', 'flake8']
         cmd.extend(args)
         p = Popen(cmd, stdout=PIPE, stderr=PIPE)

test/plugins/test_flake8_lint.py

@@ -65,3 +65,18 @@ def test_flake8_config_param(workspace):
         call_args = popen_mock.call_args.args[0]
         assert 'flake8' in call_args
         assert '--config={}'.format(flake8_conf) in call_args
+
+
+def test_flake8_executable_param(workspace):
+    with patch('pyls.plugins.flake8_lint.Popen') as popen_mock:
+        mock_instance = popen_mock.return_value
+        mock_instance.communicate.return_value = [bytes(), bytes()]
+
+        flake8_executable = '/tmp/flake8'
+        workspace._config.update({'plugins': {'flake8': {'executable': flake8_executable}}})
+
+        _name, doc = temp_document(DOC, workspace)
+        flake8_lint.pyls_lint(workspace, doc)
+
+        call_args = popen_mock.call_args.args[0]
+        assert flake8_executable in call_args