fix(errors): handle parse.ParseError without IndexError in FormatErrorMsg

yapf/yapflib/errors.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 """YAPF error objects."""
 
+from yapf_third_party._ylib2to3.pgen2 import parse
 from yapf_third_party._ylib2to3.pgen2 import tokenize
 
 
@@ -29,12 +30,26 @@ def FormatErrorMsg(e):
   Returns:
     A properly formatted error message string.
   """
+  filename = getattr(e, 'filename', None)
   if isinstance(e, SyntaxError):
-    return '{}:{}:{}: {}'.format(e.filename, e.lineno, e.offset, e.msg)
+    return '{}:{}:{}: {}'.format(filename, e.lineno, e.offset, e.msg)
   if isinstance(e, tokenize.TokenError):
-    return '{}:{}:{}: {}'.format(e.filename, e.args[1][0], e.args[1][1],
-                                 e.args[0])
-  return '{}:{}:{}: {}'.format(e.args[1][0], e.args[1][1], e.args[1][2], e.msg)
+    lineno = e.args[1][0] if len(e.args) > 1 and len(e.args[1]) > 0 else 1
+    col = e.args[1][1] if len(e.args) > 1 and len(e.args[1]) > 1 else 0
+    msg = e.args[0] if e.args else str(e)
+    return '{}:{}:{}: {}'.format(filename, lineno, col, msg)
+  if isinstance(e, parse.ParseError):
+    lineno = e.context[1][0] if e.context and len(e.context) > 1 and len(
+        e.context[1]) > 0 else 1
+    col = e.context[1][1] if e.context and len(e.context) > 1 and len(
+        e.context[1]) > 1 else 0
+    msg = e.msg if hasattr(e, 'msg') else str(e)
+    return '{}:{}:{}: {}'.format(filename, lineno, col, msg)
+  try:
+    return '{}:{}:{}: {}'.format(e.args[1][0], e.args[1][1], e.args[1][2],
+                                 e.msg)
+  except (AttributeError, IndexError, TypeError):
+    return '{}: {}'.format(filename, e) if filename else str(e)
 
 
 class YapfError(Exception):

yapftests/yapf_test.py

@@ -25,6 +25,7 @@
 import unittest
 from io import StringIO
 
+from yapf_third_party._ylib2to3.pgen2 import parse
 from yapf_third_party._ylib2to3.pgen2 import tokenize
 
 from yapf.yapflib import errors
@@ -1565,6 +1566,31 @@ def testBadCode(self):
     code = 'x = """hello\n'
     self.assertRaises(errors.YapfError, yapf_api.FormatCode, code)
 
+  def testParseError(self):
+    code = 'f"{tab["SOME_STRING"]}"\n'
+    with self.assertRaisesRegex(errors.YapfError, r'bad input'):
+      yapf_api.FormatCode(code, filename='test.py')
+
+  def testFormatErrorMsg(self):
+    s = SyntaxError('invalid syntax')
+    s.filename = 'foo.py'
+    s.lineno = 10
+    s.offset = 5
+    self.assertEqual(errors.FormatErrorMsg(s), 'foo.py:10:5: invalid syntax')
+
+    t = tokenize.TokenError('EOF in multi-line string', (2, 4))
+    t.filename = 'bar.py'
+    self.assertEqual(
+        errors.FormatErrorMsg(t), 'bar.py:2:4: EOF in multi-line string')
+
+    p = parse.ParseError('bad input', 1, 'SOME_STRING', ('', (1, 8)))
+    p.filename = 'test.py'
+    self.assertEqual(errors.FormatErrorMsg(p), 'test.py:1:8: bad input')
+
+    g = RuntimeError('unknown failure')
+    g.filename = 'baz.py'
+    self.assertEqual(errors.FormatErrorMsg(g), 'baz.py: unknown failure')
+
 
 class DiffIndentTest(yapf_test_helper.YAPFTest):