fix syntax error offsets for python 3.10 (#635)

Author: asottile

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["2.7", "3.5", "3.6", "3.7", "3.8", "3.9", "pypy2", "pypy3"]
+        python-version: ["2.7", "3.5", "3.6", "3.7", "3.8", "3.9", "3.10-dev", "pypy2", "pypy3"]
         os: [ubuntu-latest]
         # Include py2 + minimum py3 + maximum py3 + pypy + pypy3 on Windows
         include:

pyflakes/test/test_api.py

@@ -441,18 +441,25 @@ def evaluate(source):
             evaluate(source)
         except SyntaxError:
             e = sys.exc_info()[1]
-            if not PYPY:
+            if not PYPY and sys.version_info < (3, 10):
                 self.assertTrue(e.text.count('\n') > 1)
         else:
             self.fail()
 
         with self.makeTempFile(source) as sourcePath:
             if PYPY:
                 message = 'end of file (EOF) while scanning triple-quoted string literal'
+            elif sys.version_info >= (3, 10):
+                message = 'unterminated triple-quoted string literal (detected at line 8)'  # noqa: E501
             else:
                 message = 'invalid syntax'
 
-            column = 8 if sys.version_info >= (3, 8) else 11
+            if sys.version_info >= (3, 10):
+                column = 12
+            elif sys.version_info >= (3, 8):
+                column = 8
+            else:
+                column = 11
             self.assertHasErrors(
                 sourcePath,
                 ["""\
@@ -468,21 +475,25 @@ def test_eofSyntaxError(self):
         """
         with self.makeTempFile("def foo(") as sourcePath:
             if PYPY:
-                result = """\
-%s:1:7: parenthesis is never closed
-def foo(
-      ^
-""" % (sourcePath,)
+                msg = 'parenthesis is never closed'
+            elif sys.version_info >= (3, 10):
+                msg = "'(' was never closed"
             else:
-                result = """\
-%s:1:9: unexpected EOF while parsing
-def foo(
-        ^
-""" % (sourcePath,)
+                msg = 'unexpected EOF while parsing'
 
-            self.assertHasErrors(
-                sourcePath,
-                [result])
+            if PYPY:
+                column = 7
+            elif sys.version_info >= (3, 10):
+                column = 8
+            else:
+                column = 9
+
+            spaces = ' ' * (column - 1)
+            expected = '{}:1:{}: {}\ndef foo(\n{}^\n'.format(
+                sourcePath, column, msg, spaces
+            )
+
+            self.assertHasErrors(sourcePath, [expected])
 
     def test_eofSyntaxErrorWithTab(self):
         """
@@ -515,6 +526,8 @@ def foo(bar=baz, bax):
             if ERROR_HAS_LAST_LINE:
                 if PYPY:
                     column = 7
+                elif sys.version_info >= (3, 10):
+                    column = 18
                 elif sys.version_info >= (3, 9):
                     column = 21
                 elif sys.version_info >= (3, 8):

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 skip_missing_interpreters = True
 envlist =
-    py27,py34,py35,py36,py37,py38,pypy,pypy3
+    py27,py35,py36,py37,py38,py39,py310,pypy,pypy3
 
 [testenv]
 deps = flake8==3.6.0