Add type hints and mypy

15 files changed, 236 insertions, 158 deletions

diff --git a/.github/workflows/python-app.yml b/.github/workflows/python-app.yml
index 763c63e..3934f40 100644
--- a/.github/workflows/python-app.yml
+++ b/.github/workflows/python-app.yml
@@ -32,3 +32,27 @@ jobs:
       - name: Lint with pylint
         run: |
           pylint packet
+
+  typecheck:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python-version: [3.9]
+
+    steps:
+      - name: Install ldap dependencies
+        run: sudo apt-get update && sudo apt-get install libldap2-dev libsasl2-dev
+      - uses: actions/checkout@v2
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+      - name: Typecheck with mypy
+        run: |
+          # Disabled error codes to discard errors from imports
+          mypy --disable-error-code import --disable-error-code name-defined --disallow-untyped-defs --exclude routes packet
diff --git a/README.md b/README.md
index 72355f3..fb398ba 100644
--- a/README.md
+++ b/README.md
@@ -115,13 +115,14 @@ All DB commands are from the `Flask-Migrate` library and are used to configure D
 docs [here](https://flask-migrate.readthedocs.io/en/latest/) for details. 
 
 ## Code standards
-This project is configured to use Pylint. Commits will be pylinted by GitHub actions and if the score drops your build will 
-fail blocking you from merging. To make your life easier just run it before making a PR.
+This project is configured to use Pylint and mypy. Commits will be pylinted and typechecked by GitHub actions and if the
+score drops your build will fail blocking you from merging. To make your life easier just run it before making a PR.
 
-To run pylint use this command:
+To run pylint and mypy use these commands:
 ```bash
 pylint packet/routes packet
+mypy --disable-error-code import --disable-error-code name-defined --disallow-untyped-defs --exclude routes packet
 ```
 
 All python files should have a top-level docstring explaining the contents of the file and complex functions should 
-have docstrings explaining any non-obvious portions.
+have docstrings explaining any non-obvious portions. Functions should have type annotations.
diff --git a/packet/__init__.py b/packet/__init__.py
index ac6abd0..898429c 100644
--- a/packet/__init__.py
+++ b/packet/__init__.py
@@ -21,7 +21,7 @@ from sentry_sdk.integrations.sqlalchemy import SqlalchemyIntegration
 
 from .git import get_version
 
-app = Flask(__name__)
+app: Flask = Flask(__name__)
 gzip = Gzip(app)
 
 # Load default configuration and any environment variable overrides
diff --git a/packet/commands.py b/packet/commands.py
index 32dac8e..ea3591a 100644
--- a/packet/commands.py
+++ b/packet/commands.py
@@ -5,7 +5,7 @@ Defines command-line utilities for use with packet
 import sys
 
 from secrets import token_hex
-from datetime import datetime, time
+from datetime import datetime, time, date
 import csv
 import click
 
@@ -15,7 +15,7 @@ from .utils import sync_freshman, create_new_packets, sync_with_ldap
 
 
 @app.cli.command('create-secret')
-def create_secret():
+def create_secret() -> None:
     """
     Generates a securely random token. Useful for creating a value for use in the "SECRET_KEY" config setting.
     """
@@ -28,13 +28,13 @@ packet_end_time = time(hour=21)
 
 
 class CSVFreshman:
-    def __init__(self, row):
+    def __init__(self, row: list[str]) -> None:
         self.name = row[0].strip()
         self.rit_username = row[3].strip()
         self.onfloor = row[1].strip() == 'TRUE'
 
 
-def parse_csv(freshmen_csv):
+def parse_csv(freshmen_csv: str) -> dict[str, CSVFreshman]:
     print('Parsing file...')
     try:
         with open(freshmen_csv, newline='') as freshmen_csv_file:
@@ -44,7 +44,7 @@ def parse_csv(freshmen_csv):
         raise e
 
 
-def input_date(prompt):
+def input_date(prompt: str) -> date:
     while True:
         try:
             date_str = input(prompt + ' (format: MM/DD/YYYY): ')
@@ -55,7 +55,7 @@ def input_date(prompt):
 
 @app.cli.command('sync-freshmen')
 @click.argument('freshmen_csv')
-def sync_freshmen(freshmen_csv):
+def sync_freshmen(freshmen_csv: str) -> None:
     """
     Updates the freshmen entries in the DB to match the given CSV.
     """
@@ -68,7 +68,7 @@ def sync_freshmen(freshmen_csv):
 
 @app.cli.command('create-packets')
 @click.argument('freshmen_csv')
-def create_packets(freshmen_csv):
+def create_packets(freshmen_csv: str) -> None:
     """
     Creates a new packet season for each of the freshmen in the given CSV.
     """
@@ -84,7 +84,7 @@ def create_packets(freshmen_csv):
 
 
 @app.cli.command('ldap-sync')
-def ldap_sync():
+def ldap_sync() -> None:
     """
     Updates the upper and misc sigs in the DB to match ldap.
     """
@@ -97,7 +97,7 @@ def ldap_sync():
         help='The file to write to. If no file provided, output is sent to stdout.')
 @click.option('--csv/--no-csv', 'use_csv', required=False, default=False, help='Format output as comma separated list.')
 @click.option('--date', 'date_str', required=False, default='', help='Packet end date in the format MM/DD/YYYY.')
-def fetch_results(file_path, use_csv, date_str):
+def fetch_results(file_path: str, use_csv: bool, date_str: str) -> None:
     """
     Fetches and prints the results from a given packet season.
     """
@@ -150,7 +150,7 @@ def fetch_results(file_path, use_csv, date_str):
 
 @app.cli.command('extend-packet')
 @click.argument('packet_id')
-def extend_packet(packet_id):
+def extend_packet(packet_id: int) -> None:
     """
     Extends the given packet by setting a new end date.
     """
@@ -168,7 +168,7 @@ def extend_packet(packet_id):
     print('Packet successfully extended')
 
 
-def remove_sig(packet_id, username, is_member):
+def remove_sig(packet_id: int, username: str, is_member: bool) -> None:
     packet = Packet.by_id(packet_id)
 
     if not packet.is_open():
@@ -200,7 +200,7 @@ def remove_sig(packet_id, username, is_member):
 @app.cli.command('remove-member-sig')
 @click.argument('packet_id')
 @click.argument('member')
-def remove_member_sig(packet_id, member):
+def remove_member_sig(packet_id: int, member: str) -> None:
     """
     Removes the given member's signature from the given packet.
     :param member: The member's CSH username
@@ -211,7 +211,7 @@ def remove_member_sig(packet_id, member):
 @app.cli.command('remove-freshman-sig')
 @click.argument('packet_id')
 @click.argument('freshman')
-def remove_freshman_sig(packet_id, freshman):
+def remove_freshman_sig(packet_id: int, freshman: str) -> None:
     """
     Removes the given freshman's signature from the given packet.
     :param freshman: The freshman's RIT username
diff --git a/packet/context_processors.py b/packet/context_processors.py
index bff75b1..93ab115 100644
--- a/packet/context_processors.py
+++ b/packet/context_processors.py
@@ -5,14 +5,15 @@ import hashlib
 import urllib
 from functools import lru_cache
 from datetime import datetime
+from typing import Callable
 
-from packet.models import Freshman
+from packet.models import Freshman, UpperSignature
 from packet import app, ldap
 
 
 # pylint: disable=bare-except
 @lru_cache(maxsize=128)
-def get_csh_name(username):
+def get_csh_name(username: str) -> str:
     try:
         member = ldap.get_member(username)
         return member.cn + ' (' + member.uid + ')'
@@ -20,7 +21,7 @@ def get_csh_name(username):
         return username
 
 
-def get_roles(sig):
+def get_roles(sig: UpperSignature) -> dict[str, str]:
     """
     Converts a signature's role fields to a dict for ease of access.
     :return: A dictionary of role short names to role long names
@@ -45,7 +46,7 @@ def get_roles(sig):
 
 # pylint: disable=bare-except
 @lru_cache(maxsize=256)
-def get_rit_name(username):
+def get_rit_name(username: str) -> str:
     try:
         freshman = Freshman.query.filter_by(rit_username=username).first()
         return freshman.name + ' (' + username + ')'
@@ -55,7 +56,7 @@ def get_rit_name(username):
 
 # pylint: disable=bare-except
 @lru_cache(maxsize=256)
-def get_rit_image(username):
+def get_rit_image(username: str) -> str:
     if username:
         addresses = [username + '@rit.edu', username + '@g.rit.edu']
         for addr in addresses:
@@ -69,7 +70,7 @@ def get_rit_image(username):
     return 'https://www.gravatar.com/avatar/freshmen?d=mp&f=y'
 
 
-def log_time(label):
+def log_time(label: str) -> None:
     """
     Used during debugging to log timestamps while rendering templates
     """
@@ -77,7 +78,7 @@ def log_time(label):
 
 
 @app.context_processor
-def utility_processor():
+def utility_processor() -> dict[str, Callable]:
     return dict(
         get_csh_name=get_csh_name, get_rit_name=get_rit_name, get_rit_image=get_rit_image, log_time=log_time,
         get_roles=get_roles
diff --git a/packet/git.py b/packet/git.py
index 00e4d65..506276d 100644
--- a/packet/git.py
+++ b/packet/git.py
@@ -2,7 +2,7 @@ import json
 import os
 import subprocess
 
-def get_short_sha(commit_ish: str = 'HEAD'):
+def get_short_sha(commit_ish: str = 'HEAD') -> str:
     """
     Get the short hash of a commit-ish
     Returns '' if unfound
@@ -14,7 +14,7 @@ def get_short_sha(commit_ish: str = 'HEAD'):
     except subprocess.CalledProcessError:
         return ''
 
-def get_tag(commit_ish: str = 'HEAD'):
+def get_tag(commit_ish: str = 'HEAD') -> str:
     """
     Get the name of the tag at a given commit-ish
     Returns '' if untagged
@@ -26,7 +26,7 @@ def get_tag(commit_ish: str = 'HEAD'):
     except subprocess.CalledProcessError:
         return ''
 
-def get_version(commit_ish: str = 'HEAD'):
+def get_version(commit_ish: str = 'HEAD') -> str:
     """
     Get the version string of a commit-ish
 
diff --git a/packet/ldap.py b/packet/ldap.py
index 99b0367..f276484 100644
--- a/packet/ldap.py
+++ b/packet/ldap.py
@@ -4,8 +4,9 @@ Helper functions for working with the csh_ldap library
 
 from functools import lru_cache
 from datetime import date
+from typing import Optional, cast, Any
 
-from csh_ldap import CSHLDAP
+from csh_ldap import CSHLDAP, CSHMember
 
 from packet import app
 
@@ -20,32 +21,32 @@ class MockMember:
         self.cn = cn if cn else uid.title() # pylint: disable=invalid-name
 
 
-    def __eq__(self, other):
+    def __eq__(self, other: Any) -> bool:
         if type(other) is type(self):
             return self.uid == other.uid
         return False
 
 
-    def __hash__(self):
+    def __hash__(self) -> int:
         return hash(self.uid)
 
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return f'MockMember(uid: {self.uid}, groups: {self.groups})'
 
 
 class LDAPWrapper:
 
-    def __init__(self, cshldap=None, mock_members=None):
+    def __init__(self, cshldap: CSHLDAP = None, mock_members: list[MockMember] = None):
         self.ldap = cshldap
-        self.mock_members = mock_members
+        self.mock_members = cast(list[MockMember], mock_members)
         if self.ldap:
             app.logger.info('LDAP configured with CSH LDAP')
         else:
             app.logger.info('LDAP configured with local mock')
 
 
-    def _get_group_members(self, group):
+    def _get_group_members(self, group: str) -> list[CSHMember]:
         """
         :return: A list of CSHMember instances
         """
@@ -55,7 +56,7 @@ class LDAPWrapper:
             return list(filter(lambda member: group in member.groups, self.mock_members))
 
 
-    def _is_member_of_group(self, member, group):
+    def _is_member_of_group(self, member: CSHMember, group: str) -> bool:
         """
         :param member: A CSHMember instance
         """
@@ -67,7 +68,7 @@ class LDAPWrapper:
         else:
             return group in member.groups
 
-    def get_groups(self, member):
+    def get_groups(self, member: CSHMember) -> list[str]:
         if self.ldap:
             return list(
                     map(
@@ -89,7 +90,7 @@ class LDAPWrapper:
     # Getters
 
     @lru_cache(maxsize=256)
-    def get_member(self, username):
+    def get_member(self, username: str) -> CSHMember:
         """
         :return: A CSHMember instance
         """
@@ -102,7 +103,7 @@ class LDAPWrapper:
             raise KeyError('Invalid Search Name')
 
 
-    def get_active_members(self):
+    def get_active_members(self) -> list[CSHMember]:
         """
         Gets all current, dues-paying members
         :return: A list of CSHMember instances
@@ -110,7 +111,7 @@ class LDAPWrapper:
         return self._get_group_members('active')
 
 
-    def get_intro_members(self):
+    def get_intro_members(self) -> list[CSHMember]:
         """
         Gets all freshmen members
         :return: A list of CSHMember instances
@@ -118,7 +119,7 @@ class LDAPWrapper:
         return self._get_group_members('intromembers')
 
 
-    def get_eboard(self):
+    def get_eboard(self) -> list[CSHMember]:
         """
         Gets all voting members of eboard
         :return: A list of CSHMember instances
@@ -132,7 +133,7 @@ class LDAPWrapper:
         return members
 
 
-    def get_live_onfloor(self):
+    def get_live_onfloor(self) -> list[CSHMember]:
         """
         All upperclassmen who live on floor and are not eboard
         :return: A list of CSHMember instances
@@ -146,7 +147,7 @@ class LDAPWrapper:
         return members
 
 
-    def get_active_rtps(self):
+    def get_active_rtps(self) -> list[CSHMember]:
         """
         All active RTPs
         :return: A list of CSHMember instances
@@ -154,7 +155,7 @@ class LDAPWrapper:
         return [member.uid for member in self._get_group_members('active_rtp')]
 
 
-    def get_3das(self):
+    def get_3das(self) -> list[CSHMember]:
         """
         All 3das
         :return: A list of CSHMember instances
@@ -162,7 +163,7 @@ class LDAPWrapper:
         return [member.uid for member in self._get_group_members('3da')]
 
 
-    def get_webmasters(self):
+    def get_webmasters(self) -> list[CSHMember]:
         """
         All webmasters
         :return: A list of CSHMember instances
@@ -170,14 +171,14 @@ class LDAPWrapper:
         return [member.uid for member in self._get_group_members('webmaster')]
 
 
-    def get_constitutional_maintainers(self):
+    def get_constitutional_maintainers(self) -> list[CSHMember]:
         """
         All constitutional maintainers
         :return: A list of CSHMember instances
         """
         return [member.uid for member in self._get_group_members('constitutional_maintainers')]
 
-    def get_wiki_maintainers(self):
+    def get_wiki_maintainers(self) -> list[CSHMember]:
         """
         All wiki maintainers
         :return: A list of CSHMember instances
@@ -185,7 +186,7 @@ class LDAPWrapper:
         return [member.uid for member in self._get_group_members('wiki_maintainers')]
 
 
-    def get_drink_admins(self):
+    def get_drink_admins(self) -> list[CSHMember]:
         """
         All drink admins
         :return: A list of CSHMember instances
@@ -193,7 +194,7 @@ class LDAPWrapper:
         return [member.uid for member in self._get_group_members('drink')]
 
 
-    def get_eboard_role(self, member):
+    def get_eboard_role(self, member: CSHMember) -> Optional[str]:
         """
         :param member: A CSHMember instance
         :return: A String or None
@@ -224,29 +225,29 @@ class LDAPWrapper:
 
 
     # Status checkers
-    def is_eboard(self, member):
+    def is_eboard(self, member: CSHMember) -> bool:
         """
         :param member: A CSHMember instance
         """
         return self._is_member_of_group(member, 'eboard')
 
 
-    def is_evals(self, member):
+    def is_evals(self, member: CSHMember) -> bool:
         return self._is_member_of_group(member, 'eboard-evaluations')
 
 
-    def is_rtp(self, member):
+    def is_rtp(self, member: CSHMember) -> bool:
         return self._is_member_of_group(member, 'rtp')
 
 
-    def is_intromember(self, member):
+    def is_intromember(self, member: CSHMember) -> bool:
         """
         :param member: A CSHMember instance
         """
         return self._is_member_of_group(member, 'intromembers')
 
 
-    def is_on_coop(self, member):
+    def is_on_coop(self, member: CSHMember) -> bool:
         """
         :param member: A CSHMember instance
         """
@@ -256,7 +257,7 @@ class LDAPWrapper:
             return self._is_member_of_group(member, 'spring_coop')
 
 
-    def get_roomnumber(self, member): # pylint: disable=no-self-use
+    def get_roomnumber(self, member: CSHMember) -> Optional[int]: # pylint: disable=no-self-use
         """
         :param member: A CSHMember instance
         """
diff --git a/packet/log_utils.py b/packet/log_utils.py
index 5481bef..2d69f16 100644
--- a/packet/log_utils.py
+++ b/packet/log_utils.py
@@ -4,18 +4,20 @@ General utilities for logging metadata
 
 from functools import wraps
 from datetime import datetime
+from typing import Any, Callable, TypeVar, cast
 
 from packet import app, ldap
 from packet.context_processors import get_rit_name
 from packet.utils import is_freshman_on_floor
 
+WrappedFunc = TypeVar('WrappedFunc', bound=Callable)
 
-def log_time(func):
+def log_time(func: WrappedFunc) -> WrappedFunc:
     """
     Decorator for logging the execution time of a function
     """
     @wraps(func)
-    def wrapped_function(*args, **kwargs):
+    def wrapped_function(*args: list, **kwargs: dict) -> Any:
         start = datetime.now()
 
         result = func(*args, **kwargs)
@@ -25,10 +27,10 @@ def log_time(func):
 
         return result
 
-    return wrapped_function
+    return cast(WrappedFunc, wrapped_function)
 
 
-def _format_cache(func):
+def _format_cache(func: Any) -> str:
     """
     :return: The output of func.cache_info() as a compactly formatted string
     """
@@ -41,17 +43,17 @@ def _format_cache(func):
 _caches = (get_rit_name, ldap.get_member, is_freshman_on_floor)
 
 
-def log_cache(func):
+def log_cache(func: WrappedFunc) -> WrappedFunc:
     """
     Decorator for logging cache info
     """
 
     @wraps(func)
-    def wrapped_function(*args, **kwargs):
+    def wrapped_function(*args: list, **kwargs: dict) -> Any:
         result = func(*args, **kwargs)
 
         app.logger.info('Cache stats: ' + ', '.join(map(_format_cache, _caches)))
 
         return result
 
-    return wrapped_function
+    return cast(WrappedFunc, wrapped_function)
diff --git a/packet/mail.py b/packet/mail.py
index b5a4f12..5aa32f5 100644
--- a/packet/mail.py
+++ b/packet/mail.py
@@ -1,12 +1,19 @@
+from typing import TypedDict
+
 from flask import render_template
 from flask_mail import Mail, Message
 
 from packet import app
+from packet.models import Packet
 
 mail = Mail(app)
 
 
-def send_start_packet_mail(packet):
+class ReportForm(TypedDict):
+    person: str
+    report: str
+
+def send_start_packet_mail(packet: Packet) -> None:
     if app.config['MAIL_PROD']:
         recipients = ['<' + packet.freshman.rit_username + '@rit.edu>']
         msg = Message(subject='CSH Packet Starts ' + packet.start.strftime('%A, %B %-d'),
@@ -19,8 +26,7 @@ def send_start_packet_mail(packet):
         app.logger.info('Sending mail to ' + recipients[0])
         mail.send(msg)
 
-
-def send_report_mail(form_results, reporter):
+def send_report_mail(form_results: ReportForm, reporter: str) -> None:
     if app.config['MAIL_PROD']:
         recipients = ['<evals@csh.rit.edu>']
         msg = Message(subject='Packet Report',
diff --git a/packet/models.py b/packet/models.py
index b914d27..f22e467 100644
--- a/packet/models.py
+++ b/packet/models.py
@@ -4,6 +4,7 @@ Defines the application's database models
 
 from datetime import datetime
 from itertools import chain
+from typing import cast, Optional
 
 from sqlalchemy import Column, Integer, String, ForeignKey, DateTime, Boolean
 from sqlalchemy.orm import relationship
@@ -18,7 +19,7 @@ class SigCounts:
     """
     Utility class for returning counts of signatures broken out by type
     """
-    def __init__(self, upper, fresh, misc):
+    def __init__(self, upper: int, fresh: int, misc: int):
         # Base fields
         self.upper = upper
         self.fresh = fresh
@@ -34,23 +35,23 @@ class SigCounts:
 
 class Freshman(db.Model):
     __tablename__ = 'freshman'
-    rit_username = Column(String(10), primary_key=True)
-    name = Column(String(64), nullable=False)
-    onfloor = Column(Boolean, nullable=False)
-    fresh_signatures = relationship('FreshSignature')
+    rit_username = cast(str, Column(String(10), primary_key=True))
+    name = cast(str, Column(String(64), nullable=False))
+    onfloor = cast(bool, Column(Boolean, nullable=False))
+    fresh_signatures = cast('FreshSignature', relationship('FreshSignature'))
 
     # One freshman can have multiple packets if they repeat the intro process
-    packets = relationship('Packet', order_by='desc(Packet.id)')
+    packets = cast('Packet', relationship('Packet', order_by='desc(Packet.id)'))
 
     @classmethod
-    def by_username(cls, username: str):
+    def by_username(cls, username: str) -> 'Packet':
         """
         Helper method to retrieve a freshman by their RIT username
         """
         return cls.query.filter_by(rit_username=username).first()
 
     @classmethod
-    def get_all(cls):
+    def get_all(cls) -> list['Packet']:
         """
         Helper method to get all freshmen easily
         """
@@ -59,25 +60,26 @@ class Freshman(db.Model):
 
 class Packet(db.Model):
     __tablename__ = 'packet'
-    id = Column(Integer, primary_key=True, autoincrement=True)
-    freshman_username = Column(ForeignKey('freshman.rit_username'))
-    start = Column(DateTime, nullable=False)
-    end = Column(DateTime, nullable=False)
+    id = cast(int, Column(Integer, primary_key=True, autoincrement=True))
+    freshman_username = cast(str, Column(ForeignKey('freshman.rit_username')))
+    start = cast(datetime, Column(DateTime, nullable=False))
+    end = cast(datetime, Column(DateTime, nullable=False))
 
-    freshman = relationship('Freshman', back_populates='packets')
+    freshman = cast(Freshman, relationship('Freshman', back_populates='packets'))
 
     # The `lazy='subquery'` kwarg enables eager loading for signatures which makes signature calculations much faster
     # See the docs here for details: https://docs.sqlalchemy.org/en/latest/orm/loading_relationships.html
-    upper_signatures = relationship('UpperSignature', lazy='subquery',
-                                    order_by='UpperSignature.signed.desc(), UpperSignature.updated')
-    fresh_signatures = relationship('FreshSignature', lazy='subquery',
-                                    order_by='FreshSignature.signed.desc(), FreshSignature.updated')
-    misc_signatures = relationship('MiscSignature', lazy='subquery', order_by='MiscSignature.updated')
-
-    def is_open(self):
+    upper_signatures = cast('UpperSignature', relationship('UpperSignature', lazy='subquery',
+                                    order_by='UpperSignature.signed.desc(), UpperSignature.updated'))
+    fresh_signatures = cast('FreshSignature', relationship('FreshSignature', lazy='subquery',
+                                    order_by='FreshSignature.signed.desc(), FreshSignature.updated'))
+    misc_signatures = cast('MiscSignature',
+            relationship('MiscSignature', lazy='subquery', order_by='MiscSignature.updated'))
+
+    def is_open(self) -> bool:
         return self.start < datetime.now() < self.end
 
-    def signatures_required(self):
+    def signatures_required(self) -> SigCounts:
         """
         :return: A SigCounts instance with the fields set to the number of signatures received by this packet
         """
@@ -86,7 +88,7 @@ class Packet(db.Model):
 
         return SigCounts(upper, fresh, REQUIRED_MISC_SIGNATURES)
 
-    def signatures_received(self):
+    def signatures_received(self) -> SigCounts:
         """
         :return: A SigCounts instance with the fields set to the number of required signatures for this packet
         """
@@ -95,7 +97,7 @@ class Packet(db.Model):
 
         return SigCounts(upper, fresh, len(self.misc_signatures))
 
-    def did_sign(self, username, is_csh):
+    def did_sign(self, username: str, is_csh: bool) -> bool:
         """
         :param username: The CSH or RIT username to check for
         :param is_csh: Set to True for CSH accounts and False for freshmen
@@ -114,21 +116,21 @@ class Packet(db.Model):
         # The user must be a misc CSHer that hasn't signed this packet or an off-floor freshmen
         return False
 
-    def is_100(self):
+    def is_100(self) -> bool:
         """
         Checks if this packet has reached 100%
         """
         return self.signatures_required().total == self.signatures_received().total
 
     @classmethod
-    def open_packets(cls):
+    def open_packets(cls) -> list['Packet']:
         """
         Helper method for fetching all currently open packets
         """
         return cls.query.filter(cls.start < datetime.now(), cls.end > datetime.now()).all()
 
     @classmethod
-    def by_id(cls, packet_id):
+    def by_id(cls, packet_id: int) -> 'Packet':
         """
         Helper method for fetching 1 packet by its id
         """
@@ -136,43 +138,43 @@ class Packet(db.Model):
 
 class UpperSignature(db.Model):
     __tablename__ = 'signature_upper'
-    packet_id = Column(Integer, ForeignKey('packet.id'), primary_key=True)
-    member = Column(String(36), primary_key=True)
-    signed = Column(Boolean, default=False, nullable=False)
-    eboard = Column(String(12), nullable=True)
-    active_rtp = Column(Boolean, default=False, nullable=False)
-    three_da = Column(Boolean, default=False, nullable=False)
-    webmaster = Column(Boolean, default=False, nullable=False)
-    c_m = Column(Boolean, default=False, nullable=False)
-    w_m = Column(Boolean, default=False, nullable=False)
-    drink_admin = Column(Boolean, default=False, nullable=False)
-    updated = Column(DateTime, default=datetime.now, onupdate=datetime.now, nullable=False)
+    packet_id = cast(int, Column(Integer, ForeignKey('packet.id'), primary_key=True))
+    member = cast(str, Column(String(36), primary_key=True))
+    signed = cast(bool, Column(Boolean, default=False, nullable=False))
+    eboard = cast(Optional[str], Column(String(12), nullable=True))
+    active_rtp = cast(bool, Column(Boolean, default=False, nullable=False))
+    three_da = cast(bool, Column(Boolean, default=False, nullable=False))
+    webmaster = cast(bool, Column(Boolean, default=False, nullable=False))
+    c_m = cast(bool, Column(Boolean, default=False, nullable=False))
+    w_m = cast(bool, Column(Boolean, default=False, nullable=False))
+    drink_admin = cast(bool, Column(Boolean, default=False, nullable=False))
+    updated = cast(datetime, Column(DateTime, default=datetime.now, onupdate=datetime.now, nullable=False))
 
-    packet = relationship('Packet', back_populates='upper_signatures')
+    packet = cast(Packet, relationship('Packet', back_populates='upper_signatures'))
 
 
 class FreshSignature(db.Model):
     __tablename__ = 'signature_fresh'
-    packet_id = Column(Integer, ForeignKey('packet.id'), primary_key=True)
-    freshman_username = Column(ForeignKey('freshman.rit_username'), primary_key=True)
-    signed = Column(Boolean, default=False, nullable=False)
-    updated = Column(DateTime, default=datetime.now, onupdate=datetime.now, nullable=False)
+    packet_id = cast(int, Column(Integer, ForeignKey('packet.id'), primary_key=True))
+    freshman_username = cast(str, Column(ForeignKey('freshman.rit_username'), primary_key=True))
+    signed = cast(bool, Column(Boolean, default=False, nullable=False))
+    updated = cast(datetime, Column(DateTime, default=datetime.now, onupdate=datetime.now, nullable=False))
 
-    packet = relationship('Packet', back_populates='fresh_signatures')
-    freshman = relationship('Freshman', back_populates='fresh_signatures')
+    packet = cast(Packet, relationship('Packet', back_populates='fresh_signatures'))
+    freshman = cast(Freshman, relationship('Freshman', back_populates='fresh_signatures'))
 
 
 class MiscSignature(db.Model):
     __tablename__ = 'signature_misc'
-    packet_id = Column(Integer, ForeignKey('packet.id'), primary_key=True)
-    member = Column(String(36), primary_key=True)
-    updated = Column(DateTime, default=datetime.now, onupdate=datetime.now, nullable=False)
+    packet_id = cast(int, Column(Integer, ForeignKey('packet.id'), primary_key=True))
+    member = cast(str, Column(String(36), primary_key=True))
+    updated = cast(datetime, Column(DateTime, default=datetime.now, onupdate=datetime.now, nullable=False))
 
-    packet = relationship('Packet', back_populates='misc_signatures')
+    packet = cast(Packet, relationship('Packet', back_populates='misc_signatures'))
 
 
 class NotificationSubscription(db.Model):
     __tablename__ = 'notification_subscriptions'
-    member = Column(String(36), nullable=True)
-    freshman_username = Column(ForeignKey('freshman.rit_username'), nullable=True)
-    token = Column(String(256), primary_key=True, nullable=False)
+    member = cast(str, Column(String(36), nullable=True))
+    freshman_username = cast(str, Column(ForeignKey('freshman.rit_username'), nullable=True))
+    token = cast(str, Column(String(256), primary_key=True, nullable=False))
diff --git a/packet/notifications.py b/packet/notifications.py
index 69e1ab6..49b89fb 100644
--- a/packet/notifications.py
+++ b/packet/notifications.py
@@ -1,7 +1,10 @@
+from datetime import datetime
+from typing import Any, Callable, TypeVar, cast
+
 import onesignal_sdk.client as onesignal
 
 from packet import app, intro_onesignal_client, csh_onesignal_client
-from packet.models import NotificationSubscription
+from packet.models import NotificationSubscription, Packet
 
 post_body = {
     'contents': {'en': 'Default message'},
@@ -11,22 +14,24 @@ post_body = {
     'url': app.config['PROTOCOL'] + app.config['SERVER_NAME']
 }
 
-def require_onesignal_intro(func):
-    def require_onesignal_intro_wrapper(*args, **kwargs):
+WrappedFunc = TypeVar('WrappedFunc', bound=Callable)
+
+def require_onesignal_intro(func: WrappedFunc) -> WrappedFunc:
+    def require_onesignal_intro_wrapper(*args: list, **kwargs: dict) -> Any:
         if intro_onesignal_client:
             return func(*args, **kwargs)
         return None
-    return require_onesignal_intro_wrapper
+    return cast(WrappedFunc, require_onesignal_intro_wrapper)
 
-def require_onesignal_csh(func):
-    def require_onesignal_csh_wrapper(*args, **kwargs):
+def require_onesignal_csh(func: WrappedFunc) -> WrappedFunc:
+    def require_onesignal_csh_wrapper(*args: list, **kwargs: dict) -> Any:
         if csh_onesignal_client:
             return func(*args, **kwargs)
         return None
-    return require_onesignal_csh_wrapper
+    return cast(WrappedFunc, require_onesignal_csh_wrapper)
 
 
-def send_notification(notification_body, subscriptions, client):
+def send_notification(notification_body: dict, subscriptions: list, client: onesignal.Client) -> None:
     tokens = list(map(lambda subscription: subscription.token, subscriptions))
     if tokens:
         notification = onesignal.Notification(post_body=notification_body)
@@ -39,7 +44,7 @@ def send_notification(notification_body, subscriptions, client):
 
 
 @require_onesignal_intro
-def packet_signed_notification(packet, signer):
+def packet_signed_notification(packet: Packet, signer: str) -> None:
     subscriptions = NotificationSubscription.query.filter_by(freshman_username=packet.freshman_username)
     if subscriptions:
         notification_body = post_body
@@ -53,9 +58,10 @@ def packet_signed_notification(packet, signer):
 
 @require_onesignal_csh
 @require_onesignal_intro
-def packet_100_percent_notification(packet):
-    member_subscriptions = NotificationSubscription.query.filter(NotificationSubscription.member.isnot(None))
-    intro_subscriptions = NotificationSubscription.query.filter(NotificationSubscription.freshman_username.isnot(None))
+def packet_100_percent_notification(packet: Packet) -> None:
+    member_subscriptions = NotificationSubscription.query.filter(cast(Any, NotificationSubscription.member).isnot(None))
+    intro_subscriptions = NotificationSubscription.query.filter(
+            cast(Any, NotificationSubscription.freshman_username).isnot(None))
     if member_subscriptions or intro_subscriptions:
         notification_body = post_body
         notification_body['contents']['en'] = packet.freshman.name + ' got 💯 on packet!'
@@ -68,7 +74,7 @@ def packet_100_percent_notification(packet):
 
 
 @require_onesignal_intro
-def packet_starting_notification(packet):
+def packet_starting_notification(packet: Packet) -> None:
     subscriptions = NotificationSubscription.query.filter_by(freshman_username=packet.freshman_username)
     if subscriptions:
         notification_body = post_body
@@ -81,8 +87,8 @@ def packet_starting_notification(packet):
 
 
 @require_onesignal_csh
-def packets_starting_notification(start_date):
-    member_subscriptions = NotificationSubscription.query.filter(NotificationSubscription.member.isnot(None))
+def packets_starting_notification(start_date: datetime) -> None:
+    member_subscriptions = NotificationSubscription.query.filter(cast(Any, NotificationSubscription.member).isnot(None))
     if member_subscriptions:
         notification_body = post_body
         notification_body['contents']['en'] = 'New packets have started, visit packet to see them!'
diff --git a/packet/stats.py b/packet/stats.py
index 2ac5fb2..c6d6103 100644
--- a/packet/stats.py
+++ b/packet/stats.py
@@ -1,9 +1,35 @@
-from datetime import timedelta
+from datetime import date as dateType, timedelta
+from typing import TypedDict, Union, cast, Callable
 
 from packet.models import Packet, MiscSignature, UpperSignature
 
+# Types
+class Freshman(TypedDict):
+    name: str
+    rit_username: str
 
-def packet_stats(packet_id):
+class WhoSigned(TypedDict):
+    upper: list[str]
+    misc: list[str]
+    fresh: list[str]
+
+class PacketStats(TypedDict):
+    packet_id: int
+    freshman: Freshman
+    dates: dict[str, dict[str, list[str]]]
+
+class SimplePacket(TypedDict):
+    id: int
+    freshman_username: str
+
+class SigDict(TypedDict):
+    date: dateType
+    packet: SimplePacket
+
+Stats = dict[dateType, list[str]]
+
+
+def packet_stats(packet_id: int) -> PacketStats:
     """
     Gather statistics for a packet in the form of number of signatures per day
 
@@ -28,17 +54,17 @@ def packet_stats(packet_id):
 
     print(dates)
 
-    upper_stats = {date: list() for date in dates}
+    upper_stats: Stats = {date: list() for date in dates}
     for uid, date in map(lambda sig: (sig.member, sig.updated),
                          filter(lambda sig: sig.signed, packet.upper_signatures)):
         upper_stats[date.date()].append(uid)
 
-    fresh_stats = {date: list() for date in dates}
+    fresh_stats: Stats = {date: list() for date in dates}
     for username, date in map(lambda sig: (sig.freshman_username, sig.updated),
                               filter(lambda sig: sig.signed, packet.fresh_signatures)):
         fresh_stats[date.date()].append(username)
 
-    misc_stats = {date: list() for date in dates}
+    misc_stats: Stats = {date: list() for date in dates}
     for uid, date in map(lambda sig: (sig.member, sig.updated), packet.misc_signatures):
         misc_stats[date.date()].append(uid)
 
@@ -60,7 +86,7 @@ def packet_stats(packet_id):
             }
 
 
-def sig2dict(sig):
+def sig2dict(sig: Union[UpperSignature, MiscSignature]) -> SigDict:
     """
     A utility function for upperclassman stats.
     Converts an UpperSignature to a dictionary with the date and the packet.
@@ -74,8 +100,11 @@ def sig2dict(sig):
                 },
             }
 
+class UpperStats(TypedDict):
+    member: str
+    signatures: dict[str, list[SimplePacket]]
 
-def upperclassman_stats(uid):
+def upperclassman_stats(uid: str) -> UpperStats:
     """
     Gather statistics for an upperclassman's signature habits
 
@@ -104,7 +133,7 @@ def upperclassman_stats(uid):
             'signatures': {
                 date.isoformat() : list(
                     map(lambda sd: sd['packet'],
-                        filter(lambda sig, d=date: sig['date'] == d,
+                        filter(cast(Callable, lambda sig, d=date: sig['date'] == d),
                             sig_dicts
                             )
                         )
diff --git a/packet/utils.py b/packet/utils.py
index ff2f5a6..ea4693b 100644
--- a/packet/utils.py
+++ b/packet/utils.py
@@ -3,6 +3,7 @@ General utilities and decorators for supporting the Python logic
 """
 from datetime import datetime, time, timedelta, date
 from functools import wraps, lru_cache
+from typing import Any, Callable, TypeVar, cast
 
 import requests
 from flask import session, redirect
@@ -14,15 +15,16 @@ from packet.notifications import packets_starting_notification, packet_starting_
 
 INTRO_REALM = 'https://sso.csh.rit.edu/auth/realms/intro'
 
+WrappedFunc = TypeVar('WrappedFunc', bound=Callable)
 
-def before_request(func):
+def before_request(func: WrappedFunc) -> WrappedFunc:
     """
     Credit to Liam Middlebrook and Ram Zallan
     https://github.com/liam-middlebrook/gallery
     """
 
     @wraps(func)
-    def wrapped_function(*args, **kwargs):
+    def wrapped_function(*args: list, **kwargs: dict) -> Any:
         uid = str(session['userinfo'].get('preferred_username', ''))
         if session['id_token']['iss'] == INTRO_REALM:
             info = {
@@ -43,11 +45,11 @@ def before_request(func):
         kwargs['info'] = info
         return func(*args, **kwargs)
 
-    return wrapped_function
+    return cast(WrappedFunc, wrapped_function)
 
 
 @lru_cache(maxsize=128)
-def is_freshman_on_floor(rit_username):
+def is_freshman_on_floor(rit_username: str) -> bool:
     """
     Checks if a freshman is on floor
     """
@@ -58,14 +60,14 @@ def is_freshman_on_floor(rit_username):
         return False
 
 
-def packet_auth(func):
+def packet_auth(func: WrappedFunc) -> WrappedFunc:
     """
     Decorator for easily configuring oidc
     """
 
     @auth.oidc_auth('app')
     @wraps(func)
-    def wrapped_function(*args, **kwargs):
+    def wrapped_function(*args: list, **kwargs: dict) -> Any:
         if app.config['REALM'] == 'csh':
             username = str(session['userinfo'].get('preferred_username', ''))
             if ldap.is_intromember(ldap.get_member(username)):
@@ -74,17 +76,17 @@ def packet_auth(func):
 
         return func(*args, **kwargs)
 
-    return wrapped_function
+    return cast(WrappedFunc, wrapped_function)
 
 
-def admin_auth(func):
+def admin_auth(func: WrappedFunc) -> WrappedFunc:
     """
     Decorator for easily configuring oidc
     """
 
     @auth.oidc_auth('app')
     @wraps(func)
-    def wrapped_function(*args, **kwargs):
+    def wrapped_function(*args: list, **kwargs: dict) -> Any:
         if app.config['REALM'] == 'csh':
             username = str(session['userinfo'].get('preferred_username', ''))
             member = ldap.get_member(username)
@@ -96,10 +98,10 @@ def admin_auth(func):
 
         return func(*args, **kwargs)
 
-    return wrapped_function
+    return cast(WrappedFunc, wrapped_function)
 
 
-def notify_slack(name: str):
+def notify_slack(name: str) -> None:
     """
     Sends a congratulate on sight decree to Slack
     """
@@ -112,7 +114,7 @@ def notify_slack(name: str):
     app.logger.info('Posted 100% notification to slack for ' + name)
 
 
-def sync_freshman(freshmen_list: dict):
+def sync_freshman(freshmen_list: dict) -> None:
     freshmen_in_db = {freshman.rit_username: freshman for freshman in Freshman.query.all()}
 
     for list_freshman in freshmen_list.values():
@@ -150,7 +152,7 @@ def sync_freshman(freshmen_list: dict):
     db.session.commit()
 
 
-def create_new_packets(base_date: date, freshmen_list: dict):
+def create_new_packets(base_date: date, freshmen_list: dict) -> None:
     packet_start_time = time(hour=19)
     packet_end_time = time(hour=21)
     start = datetime.combine(base_date, packet_start_time)
@@ -173,7 +175,7 @@ def create_new_packets(base_date: date, freshmen_list: dict):
 
     # Create the new packets and the signatures for each freshman in the given CSV
     print('Creating DB entries and sending emails...')
-    for freshman in Freshman.query.filter(Freshman.rit_username.in_(freshmen_list)).all():
+    for freshman in Freshman.query.filter(cast(Any, Freshman.rit_username).in_(freshmen_list)).all():
         packet = Packet(freshman=freshman, start=start, end=end)
         db.session.add(packet)
         send_start_packet_mail(packet)
@@ -197,7 +199,7 @@ def create_new_packets(base_date: date, freshmen_list: dict):
     db.session.commit()
 
 
-def sync_with_ldap():
+def sync_with_ldap() -> None:
     print('Fetching data from LDAP...')
     all_upper = {member.uid: member for member in filter(
         lambda member: not ldap.is_intromember(member) and not ldap.is_on_coop(member), ldap.get_active_members())}
diff --git a/requirements.txt b/requirements.txt
index cda0b3b..dcb44ae 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,14 +1,16 @@
-csh_ldap~=2.3.1
-ddtrace
-Flask~=1.1.2
 Flask-Gzip~=0.2
 Flask-Mail~=0.9.1
 Flask-Migrate~=2.7.0
 Flask-pyoidc~=3.7.0
+Flask~=1.1.2
+csh_ldap~=2.3.1
+ddtrace
 flask_sqlalchemy~=2.4.4
 gunicorn~=20.0.4
+mypy
 onesignal-sdk~=2.0.0
 psycopg2-binary~=2.8.6
-pylint~=2.7.2
 pylint-quotes~=0.2.1
+pylint~=2.7.2
 sentry-sdk~=1.0.0
+sqlalchemy[mypy]
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..37543e3
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,2 @@
+[mypy]
+plugins=sqlalchemy.ext.mypy.plugin