Add mypy typings (#4)

.travis.yml

@@ -2,7 +2,6 @@ language: python
 sudo: false
 cache: pip
 
-install: pip install tox
 matrix:
   include:
     - python: 2.7
@@ -20,7 +19,14 @@ matrix:
     - python: 3.8
       env:
         - TOX_ENV=py38
-script: tox -e $TOX_ENV
+
+install:
+  - pip install tox
+  - "if ! [[ $TRAVIS_PYTHON_VERSION = '2.7' ]]; then pip install mypy; fi"
+
+script:
+  - "if ! [[ $TRAVIS_PYTHON_VERSION = '2.7' ]]; then mypy pylti1p3/ && mypy --py2 pylti1p3/; fi"
+  - tox -e $TOX_ENV
 
 notifications:
   email:

pylintrc

@@ -72,6 +72,10 @@ disable=
 # python2-compatible
     useless-object-inheritance,
 
+# Conditional imports for type checking
+    unused-import,
+    import-error,
+
 [REPORTS]
 
 # Set the output format. Available formats are text, parseable, colorized, msvs

pylti1p3/actions.py

@@ -1,3 +1,9 @@
+import typing as t
+
+if t.TYPE_CHECKING:
+    from typing_extensions import Final
+
+
 class Action(object):
-    OIDC_LOGIN = 'oidc_login'
-    MESSAGE_LAUNCH = 'message_launch'
+    OIDC_LOGIN = 'oidc_login'  # type: Final
+    MESSAGE_LAUNCH = 'message_launch'  # type: Final

pylti1p3/assignments_grades.py

@@ -1,16 +1,34 @@
+import typing as t
+
 from .exception import LtiException
 from .lineitem import LineItem
 
+if t.TYPE_CHECKING:
+    from .service_connector import ServiceConnector, _ServiceConnectorResponse
+    from .grade import Grade
+    from mypy_extensions import TypedDict
+    from typing_extensions import Literal
+
+    _AssignmentsGradersData = TypedDict('_AssignmentsGradersData', {
+        'scope': t.List[Literal['https://purl.imsglobal.org/spec/lti-ags/scope/score',
+                                'https://purl.imsglobal.org/spec/lti-ags/scope/lineitem',
+                                'https://purl.imsglobal.org/spec/lti-ags/scope/lineitem.readonly']],
+        'lineitems': str,
+        'lineitem': str,
+    }, total=False)
+
 
 class AssignmentsGradesService(object):
-    _service_connector = None
-    _service_data = None
+    _service_connector = None  # type: ServiceConnector
+    _service_data = None  # type: _AssignmentsGradersData
 
     def __init__(self, service_connector, service_data):
+        # type: (ServiceConnector, _AssignmentsGradersData) -> None
         self._service_connector = service_connector
         self._service_data = service_data
 
     def put_grade(self, grade, line_item=None):
+        # type: (Grade, t.Optional[LineItem]) -> _ServiceConnectorResponse
         if "https://purl.imsglobal.org/spec/lti-ags/scope/score" not in self._service_data['scope']:
             raise LtiException('Missing required scope')
 
@@ -27,6 +45,7 @@ def put_grade(self, grade, line_item=None):
                 line_item = self.find_or_create_lineitem(line_item)
             score_url = line_item.get_id()
 
+        assert score_url is not None
         score_url = self._add_url_path_ending(score_url, 'scores')
         return self._service_connector.make_service_request(
             self._service_data['scope'],
@@ -37,6 +56,7 @@ def put_grade(self, grade, line_item=None):
         )
 
     def get_lineitems(self):
+        # type: () -> list
         if "https://purl.imsglobal.org/spec/lti-ags/scope/lineitem" not in self._service_data['scope']:
             raise LtiException('Missing required scope')
 
@@ -45,9 +65,12 @@ def get_lineitems(self):
             self._service_data['lineitems'],
             accept='application/vnd.ims.lis.v2.lineitemcontainer+json'
         )
+        if not isinstance(line_items['body'], list):
+            raise LtiException('Unknown response type received for line items')
         return line_items['body']
 
     def find_lineitem_by_id(self, ln_id):
+        # type: (t.Optional[str]) -> t.Optional[LineItem]
         line_items = self.get_lineitems()
 
         for line_item in line_items:
@@ -57,6 +80,7 @@ def find_lineitem_by_id(self, ln_id):
         return None
 
     def find_lineitem_by_tag(self, tag):
+        # type: (t.Optional[str]) -> t.Optional[LineItem]
         line_items = self.get_lineitems()
 
         for line_item in line_items:
@@ -66,10 +90,13 @@ def find_lineitem_by_tag(self, tag):
         return None
 
     def find_or_create_lineitem(self, new_line_item, find_by='tag'):
+        # type: (LineItem, Literal['tag', 'id']) -> LineItem
         if find_by == 'tag':
-            line_item = self.find_lineitem_by_tag(new_line_item.get_tag())
+            tag = new_line_item.get_tag()
+            line_item = self.find_lineitem_by_tag(tag)
         elif find_by == 'id':
-            line_item = self.find_lineitem_by_id(new_line_item.get_id())
+            line_id = new_line_item.get_id()
+            line_item = self.find_lineitem_by_id(line_id)
         else:
             raise LtiException('Invalid "find_by" value: ' + str(find_by))
 
@@ -84,28 +111,38 @@ def find_or_create_lineitem(self, new_line_item, find_by='tag'):
             content_type='application/vnd.ims.lis.v2.lineitem+json',
             accept='application/vnd.ims.lis.v2.lineitem+json'
         )
+        if not isinstance(created_line_item['body'], dict):
+            raise LtiException('Unknown response type received for create line item')
         return LineItem(created_line_item['body'])
 
     def get_grades(self, line_item):
+        # type: (LineItem) -> list
         line_item_id = line_item.get_id()
         line_item_tag = line_item.get_tag()
 
-        find_by = None
+        find_by = None  # type: t.Optional[Literal['id', 'tag']]
         if line_item_id:
             find_by = 'id'
         elif line_item_tag:
             find_by = 'tag'
+        else:
+            raise LtiException('Received LineItem did not contain a tag or id')
 
         line_item = self.find_or_create_lineitem(line_item, find_by=find_by)
-        results_url = self._add_url_path_ending(line_item.get_id(), 'results')
+        line_item_id = line_item.get_id()
+        assert line_item_id is not None
+        results_url = self._add_url_path_ending(line_item_id, 'results')
         scores = self._service_connector.make_service_request(
             self._service_data['scope'],
             results_url,
             accept='application/vnd.ims.lis.v2.resultcontainer+json'
         )
+        if not isinstance(scores['body'], list):
+            raise LtiException('Unknown response type received for results')
         return scores['body']
 
     def _add_url_path_ending(self, url, url_path_ending):
+        # type: (str, str) -> str
         if '?' in url:
             url_parts = url.split('?')
             new_url = url_parts[0]

pylti1p3/contrib/django/cookie.py

@@ -1,15 +1,18 @@
-import django
+import sys
+import typing as t
 
+import django  # type: ignore
 from pylti1p3.cookie import CookieService
-try:
-    import Cookie
-except ImportError:
-    import http.cookies as Cookie
+
+if sys.version_info[0] > 2:
+    import http.cookies as Cookie  # type: ignore
+else:
+    import Cookie  # type: ignore
 
 # Add support for the SameSite attribute (obsolete when PY37 is unsupported).
 # pylint: disable=protected-access
-if 'samesite' not in Cookie.Morsel._reserved:
-    Cookie.Morsel._reserved.setdefault('samesite', 'SameSite')
+if 'samesite' not in Cookie.Morsel._reserved:  # type: ignore
+    Cookie.Morsel._reserved.setdefault('samesite', 'SameSite')  # type: ignore
 
 
 class DjangoCookieService(CookieService):

pylti1p3/contrib/django/launch_data_storage/cache.py

@@ -1,4 +1,4 @@
-from django.core.cache import caches
+from django.core.cache import caches  # type: ignore
 from pylti1p3.launch_data_storage.cache import CacheDataStorage
 
 

pylti1p3/contrib/django/lti1p3_tool_config/admin.py

@@ -1,4 +1,6 @@
+# mypy: ignore-errors
 from django.contrib import admin
+
 from .models import LtiTool, LtiToolKey
 
 

pylti1p3/contrib/django/lti1p3_tool_config/apps.py

@@ -1,4 +1,4 @@
-from django.apps import AppConfig
+from django.apps import AppConfig  # type: ignore
 
 
 class PyLTI1p3ToolConfig(AppConfig):

pylti1p3/contrib/django/lti1p3_tool_config/migrations/0001_initial.py

@@ -1,6 +1,7 @@
+# mypy: ignore-errors
 import django.core.validators
-from django.db import migrations, models
 import django.db.models.deletion
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):

pylti1p3/contrib/django/lti1p3_tool_config/models.py

@@ -1,9 +1,10 @@
+# mypy: ignore-errors
 import json
 
-from django.core.validators import URLValidator
 from django.core.exceptions import ValidationError
-from django.utils.translation import ugettext_lazy as _
+from django.core.validators import URLValidator
 from django.db import models
+from django.utils.translation import ugettext_lazy as _
 from pylti1p3.registration import Registration
 
 

pylti1p3/contrib/django/oidc_login.py

@@ -1,6 +1,7 @@
-from django.http import HttpResponse
+from django.http import HttpResponse  # type: ignore
 from pylti1p3.oidc_login import OIDCLogin
 from pylti1p3.request import Request
+
 from .cookie import DjangoCookieService
 from .redirect import DjangoRedirect
 from .request import DjangoRequest

pylti1p3/contrib/django/redirect.py

@@ -1,5 +1,5 @@
-from django.http import HttpResponse
-from django.shortcuts import redirect
+from django.http import HttpResponse  # type: ignore
+from django.shortcuts import redirect  # type: ignore
 from pylti1p3.redirect import Redirect
 
 
@@ -8,6 +8,7 @@ class DjangoRedirect(Redirect):
     _cookie_service = None
 
     def __init__(self, location, cookie_service=None):
+        super(DjangoRedirect, self).__init__()
         self._location = location
         self._cookie_service = cookie_service
 

pylti1p3/contrib/django/request.py

@@ -6,6 +6,10 @@ class DjangoRequest(Request):
     _post_only = False
     _default_params = None
 
+    @property
+    def session(self):
+        return self._request.session
+
     def __init__(self, request, post_only=False, default_params=None):
         self.set_request(request)
         self._post_only = post_only

pylti1p3/contrib/flask/redirect.py

@@ -8,6 +8,7 @@ class FlaskRedirect(Redirect):
     _cookie_service = None
 
     def __init__(self, location, cookie_service=None):
+        super(FlaskRedirect, self).__init__()
         self._location = location
         self._cookie_service = cookie_service
 

pylti1p3/contrib/flask/request.py

@@ -1,15 +1,21 @@
-from flask import request, session as flask_session
+import typing as t
 
+from flask import request
+from flask import session as flask_session
 from pylti1p3.request import Request
 
+if t.TYPE_CHECKING:
+    from pylti1p3.request import SessionLike
+
 
 class FlaskRequest(Request):
-    session = None
+    session = None  # type: SessionLike
     _cookies = None
     _request_data = None
     _request_is_secure = None
 
     def __init__(self, cookies=None, session=None, request_data=None, request_is_secure=None):
+        super(FlaskRequest, self).__init__()
         self._cookies = request.cookies if cookies is None else cookies
         self.session = flask_session if session is None else session
         self._request_is_secure = request.is_secure if request_is_secure is None else request_is_secure

pylti1p3/cookie.py

@@ -1,14 +1,17 @@
+import typing as t
 from abc import ABCMeta, abstractmethod
 
 
 class CookieService(object):
     __metaclass__ = ABCMeta
-    _cookie_prefix = 'lti1p3'
+    _cookie_prefix = 'lti1p3'  # type: str
 
     @abstractmethod
     def get_cookie(self, name):
+        # type: (str) -> t.Optional[str]
         raise NotImplementedError
 
     @abstractmethod
     def set_cookie(self, name, value, exp=3600):
+        # type: (str, str, int) -> None
         raise NotImplementedError

pylti1p3/cookies_allowed_check.py

@@ -1,14 +1,16 @@
 import json
+import typing as t
 
 
 class CookiesAllowedCheckPage(object):
-    _params = {}
-    _protocol = 'http'
-    _main_text = ''
-    _click_text = ''
-    _loading_text = ''
+    _params = {}  # type: t.Mapping[str, str]
+    _protocol = 'http'  # type: str
+    _main_text = ''  # type: str
+    _click_text = ''  # type: str
+    _loading_text = ''  # type: str
 
     def __init__(self, params, protocol, main_text, click_text, loading_text, *args, **kwargs):
+        # type: (t.Mapping[str, str], str, str, str, str, *None, **None) -> None
         # pylint: disable=unused-argument
         self._params = params
         self._protocol = protocol
@@ -17,6 +19,7 @@ def __init__(self, params, protocol, main_text, click_text, loading_text, *args,
         self._loading_text = loading_text
 
     def get_css_block(self):
+        # type: () -> str
         css_block = """\
         body {
         font-family: Geneva, Arial, Helvetica, sans-serif;
@@ -25,6 +28,7 @@ def get_css_block(self):
         return css_block
 
     def get_js_block(self):
+        # type: () -> str
         js_block = """\
         var siteProtocol = '%s';
         var urlParams = %s;
@@ -84,9 +88,11 @@ def get_js_block(self):
         return js_block
 
     def get_header_block(self):
+        # type: () -> str
         return ''
 
     def get_html(self):
+        # type: () -> str
         html = """\
         <!DOCTYPE html>
         <html lang="en">