Handle migration of both files and dirs

cli-v1-to-v2

@@ -36,7 +36,7 @@ def main(sysargs=sys.argv[:]):
     parser = argparse.ArgumentParser(
         description=_DESCRIPTION,
         formatter_class=argparse.ArgumentDefaultsHelpFormatter)
-    parser.add_argument('basedir', nargs='?', metavar='BASEDIR',
+    parser.add_argument('path', nargs='+',
                         type=os.path.abspath, default=os.getcwd())
     parser.add_argument('-w', '--write', help='write changes back to file',
                         action='store_true', default=False)
@@ -60,7 +60,7 @@ def main(sysargs=sys.argv[:]):
         format='%(message)s'
     )
 
-    for filepath in _find_candidate_files(args.basedir):
+    for filepath in _find_candidate_files(args.path):
         updated_source = _update_filepath(filepath)
         if args.write:
             logging.info('Updating %s', filepath)
@@ -74,21 +74,26 @@ def main(sysargs=sys.argv[:]):
     return 0
 
 
-def _find_candidate_files(basedir):
+def _find_candidate_files(paths):
-    for curdir, dirs, files in os.walk(basedir):
+    for path in paths:
-        for i, dirname in enumerate(dirs[:]):
+        if not os.path.isdir(path):
-            if dirname.startswith('.'):
+            yield path
-                dirs.pop(i)
+            continue
 
-        for filename in files:
+        for curdir, dirs, files in os.walk(path):
-            if not filename.endswith('.go'):
+            for i, dirname in enumerate(dirs[:]):
-                continue
+                if dirname.startswith('.'):
+                    dirs.pop(i)
 
-            filepath = os.path.join(curdir, filename)
+            for filename in files:
-            if not os.access(filepath, os.R_OK | os.W_OK):
+                if not filename.endswith('.go'):
-                continue
+                    continue
 
-            yield filepath
+                filepath = os.path.join(curdir, filename)
+                if not os.access(filepath, os.R_OK | os.W_OK):
+                    continue
+
+                yield filepath
 
 
 def _update_filepath(filepath):