[tox] Fix a few invalid type annotations (#50)

Some type annotations are using nested types of the TestSuiteDB
class. However, these nested types are actually defined in the
__init__ method of TestSuiteDB and are hence not accessible as a
class member. The easiest fix seems to be to downgrade these type
annotations back to comments, at least for now.

In a few other places, add missing annotations to make mypy happy
and add `# noqa` to work around flake8 flagging imports as unused
(when in reality they are required for mypy annotations).

Finally, make the mypy test non-optional so it shows up as a failure
when we break it. We are clearly missing a lot of annotations, but
at least we have a basis that we can build upon and avoid regressing.

Author: ldionne

lnt/server/db/fieldchange.py

@@ -4,6 +4,7 @@
 from sqlalchemy.orm.session import Session
 from sqlalchemy.orm.exc import ObjectDeletedError
 from typing import Tuple, List
+import typing
 
 import lnt.server.reporting.analysis
 from lnt.testing.util.commands import timed
@@ -27,7 +28,7 @@ def post_submit_tasks(session, ts, run_id):
     regenerate_fieldchanges_for_run(session, ts, run_id)
 
 
-def delete_fieldchange(session: Session, ts: TestSuiteDB, change: TestSuiteDB.FieldChange) -> List[int]:
+def delete_fieldchange(session: Session, ts: TestSuiteDB, change) -> List[int]:
     """Delete this field change.  Since it might be attahed to a regression
     via regression indicators, fix those up too.  If this orphans a regression
     delete it as well."""
@@ -36,7 +37,7 @@ def delete_fieldchange(session: Session, ts: TestSuiteDB, change: TestSuiteDB.Fi
         filter(ts.RegressionIndicator.field_change_id == change.id). \
         all()
     # And all the related regressions.
-    regression_ids = [r.regression_id for r in indicators]
+    regression_ids: List[int] = [r.regression_id for r in indicators]
 
     # Remove the idicators that point to this change.
     for ind in indicators:
@@ -47,13 +48,13 @@ def delete_fieldchange(session: Session, ts: TestSuiteDB, change: TestSuiteDB.Fi
 
     # We might have just created a regression with no changes.
     # If so, delete it as well.
-    deleted_ids = []
+    deleted_ids: List[int] = []
     for r in regression_ids:
         remaining = session.query(ts.RegressionIndicator). \
             filter(ts.RegressionIndicator.regression_id == r). \
             all()
         if len(remaining) == 0:
-            r = session.query(ts.Regression).get(r)
+            r = typing.cast(int, session.query(ts.Regression).get(r))
             logger.info("Deleting regression because it has not changes:" +
                         repr(r))
             session.delete(r)
@@ -224,7 +225,7 @@ def percent_similar(a: str, b: str) -> float:
 @timed
 def identify_related_changes(session: Session,
                              ts: TestSuiteDB,
-                             fc: TestSuiteDB.FieldChange,
+                             fc,  # TestSuiteDB.FieldChange
                              active_changes: List) -> Tuple[bool, List]:
     """Can we find a home for this change in some existing regression? If a
     match is found add a regression indicator adding this change to that

lnt/server/db/rules/rule_update_fixed_regressions.py

@@ -34,7 +34,7 @@ def is_fixed(session, ts, regression):
     return all(fixes)
 
 
-def impacts(session: Session, ts: TestSuiteDB, run_id: int, regression: TestSuiteDB.Regression) -> bool:
+def impacts(session: Session, ts: TestSuiteDB, run_id: int, regression) -> bool:
     """Does this run have a chance of impacting this regression?
 
     This is just to prevent doing a full comparison, so we don't have

lnt/server/ui/views.py

@@ -3,6 +3,7 @@
 import os
 import re
 import time
+import typing  # noqa: F401
 from collections import namedtuple, defaultdict
 from urllib.parse import urlparse, urljoin
 from io import BytesIO
@@ -20,7 +21,6 @@
 from flask_wtf import Form
 from sqlalchemy.orm import joinedload
 from sqlalchemy.orm.exc import NoResultFound
-from typing import Optional
 from wtforms import SelectField, StringField, SubmitField
 from wtforms.validators import DataRequired, Length
 
@@ -36,7 +36,7 @@
 import lnt.util.ImportData
 import lnt.util.stats
 from lnt.external.stats import stats as ext_stats
-from lnt.server.db import testsuitedb
+from lnt.server.db import testsuitedb  # noqa: F401
 from lnt.server.reporting.analysis import ComparisonResult, calc_geomean
 from lnt.server.ui import util
 from lnt.server.ui.decorators import frontend, db_route, v4_route
@@ -1844,7 +1844,8 @@ class MatrixOptions(Form):
     limit = SelectField('Size', choices=MATRIX_LIMITS)
 
 
-def baseline() -> Optional[testsuitedb.TestSuiteDB.Baseline]:
+def baseline():
+    # type: () -> typing.Optional[testsuitedb.TestSuiteDB.Baseline]
     """Get the baseline object from the user's current session baseline value
     or None if one is not defined.
     """

tox.ini

@@ -24,12 +24,11 @@ deps =
     types-certifi
 
 commands =
-    # Nowhere close to passing yet, but nice to have. The option
-    # --no-incremental is currently needed to suppress warnings about
-    # UpdatedBase when running tests several times. Future versions of
+    # The option --no-incremental is currently needed to suppress warnings
+    # about UpdatedBase when running tests several times. Future versions of
     # mypy should be checked to see if it can be removed and not get
     # warnings after running tox several times.
-    - mypy --no-incremental --junit-xml=junit-{envname}.xml --ignore-missing-imports lnt
+    mypy --no-incremental --junit-xml=junit-{envname}.xml --ignore-missing-imports lnt
 
 [testenv:flake8]
 skip_install = true