Add I301 check for if TYPE_CHECKING: separated from other imports

Author: dgw

flake8_import_order/styles.py

@@ -48,6 +48,7 @@ def _check(self, previous_import, previous, current_import):
             and current_import.type_checking
         ):
             yield from self._check_I300(previous_import, current_import)
+            yield from self._check_I301(previous_import, current_import)
             previous_import = None
         if previous_import is not None:
             yield from self._check_I100(previous_import, current_import)
@@ -78,13 +79,21 @@ def _check_I101(self, current_import):  # noqa: N802
             )
 
     def _check_I300(self, previous_import, current_import):  # noqa: N802
-        if current_import.lineno - previous_import.end_lineno != 3:
+        if current_import.lineno - previous_import.end_lineno < 3:
             yield Error(
                 current_import.lineno,
                 "I300",
                 "TYPE_CHECKING block should have one newline above.",
             )
 
+    def _check_I301(self, previous_import, current_import):  # noqa: N802
+        if current_import.lineno - previous_import.end_lineno > 3:
+            yield Error(
+                current_import.lineno,
+                "I301",
+                "TYPE_CHECKING block should have no more than one newline above.",
+            )
+
     def _check_I100(self, previous_import, current_import):  # noqa: N802
         previous_key = self.import_key(previous_import)
         current_key = self.import_key(current_import)

tests/test_cases/type_checking_orphaned.py

@@ -0,0 +1,11 @@
+# cryptography edited google pep8 smarkets
+from typing import TYPE_CHECKING
+
+import pytest
+
+from . import localpackage
+
+CONST = localpackage.CONST
+
+if TYPE_CHECKING:
+    import ast  # I301