Bump `mypy` from 1.8.0 to 1.9.0 (#17297)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

1 files changed, 24 insertions, 4 deletions

diff --git a/tests/rest/client/test_account.py b/tests/rest/client/test_account.py
index 992421ffe2..a85ea994de 100644
--- a/tests/rest/client/test_account.py
+++ b/tests/rest/client/test_account.py
@@ -427,13 +427,23 @@ class PasswordResetTestCase(unittest.HomeserverTestCase):
         text = None
         for part in mail.walk():
             if part.get_content_type() == "text/plain":
-                text = part.get_payload(decode=True).decode("UTF-8")
+                text = part.get_payload(decode=True)
+                if text is not None:
+                    # According to the logic table in `get_payload`, we know that
+                    # the result of `get_payload` will be `bytes`, but mypy doesn't
+                    # know this and complains. Thus, we assert the type.
+                    assert isinstance(text, bytes)
+                    text = text.decode("UTF-8")
+
                 break
 
         if not text:
             self.fail("Could not find text portion of email to parse")
 
-        assert text is not None
+        # `text` must be a `str`, after being decoded and determined just above
+        # to not be `None` or an empty `str`.
+        assert isinstance(text, str)
+
         match = re.search(r"https://example.com\S+", text)
         assert match, "Could not find link in email"
 
@@ -1209,13 +1219,23 @@ class ThreepidEmailRestTestCase(unittest.HomeserverTestCase):
         text = None
         for part in mail.walk():
             if part.get_content_type() == "text/plain":
-                text = part.get_payload(decode=True).decode("UTF-8")
+                text = part.get_payload(decode=True)
+                if text is not None:
+                    # According to the logic table in `get_payload`, we know that
+                    # the result of `get_payload` will be `bytes`, but mypy doesn't
+                    # know this and complains. Thus, we assert the type.
+                    assert isinstance(text, bytes)
+                    text = text.decode("UTF-8")
+
                 break
 
         if not text:
             self.fail("Could not find text portion of email to parse")
 
-        assert text is not None
+        # `text` must be a `str`, after being decoded and determined just above
+        # to not be `None` or an empty `str`.
+        assert isinstance(text, str)
+
         match = re.search(r"https://example.com\S+", text)
         assert match, "Could not find link in email"