1 files changed, 34 insertions, 0 deletions
diff --git a/Lib/test/test_genericpath.py b/Lib/test/test_genericpath.py
index e59ed4d..f2722bc 100644
--- a/Lib/test/test_genericpath.py
+++ b/Lib/test/test_genericpath.py
@@ -434,6 +434,40 @@ class CommonTest(GenericTest):
             with support.temp_cwd(name):
                 self.test_abspath()
 
+    def test_join_errors(self):
+        # Check join() raises friendly TypeErrors.
+        with support.check_warnings(('', BytesWarning), quiet=True):
+            errmsg = "Can't mix strings and bytes in path components"
+            with self.assertRaisesRegex(TypeError, errmsg):
+                self.pathmodule.join(b'bytes', 'str')
+            with self.assertRaisesRegex(TypeError, errmsg):
+                self.pathmodule.join('str', b'bytes')
+            # regression, see #15377
+            errmsg = r'join\(\) argument must be str or bytes, not %r'
+            with self.assertRaisesRegex(TypeError, errmsg % 'int'):
+                self.pathmodule.join(42, 'str')
+            with self.assertRaisesRegex(TypeError, errmsg % 'int'):
+                self.pathmodule.join('str', 42)
+            with self.assertRaisesRegex(TypeError, errmsg % 'bytearray'):
+                self.pathmodule.join(bytearray(b'foo'), bytearray(b'bar'))
+
+    def test_relpath_errors(self):
+        # Check relpath() raises friendly TypeErrors.
+        with support.check_warnings(('', (BytesWarning, DeprecationWarning)),
+                                    quiet=True):
+            errmsg = "Can't mix strings and bytes in path components"
+            with self.assertRaisesRegex(TypeError, errmsg):
+                self.pathmodule.relpath(b'bytes', 'str')
+            with self.assertRaisesRegex(TypeError, errmsg):
+                self.pathmodule.relpath('str', b'bytes')
+            errmsg = r'relpath\(\) argument must be str or bytes, not %r'
+            with self.assertRaisesRegex(TypeError, errmsg % 'int'):
+                self.pathmodule.relpath(42, 'str')
+            with self.assertRaisesRegex(TypeError, errmsg % 'int'):
+                self.pathmodule.relpath('str', 42)
+            with self.assertRaisesRegex(TypeError, errmsg % 'bytearray'):
+                self.pathmodule.relpath(bytearray(b'foo'), bytearray(b'bar'))
+
 
 if __name__=="__main__":
     unittest.main()