Add tox config and mypy typechecks.

Pipfile

@@ -13,3 +13,5 @@ bumpversion = "*"
 "flake8" = "*"
 moto = "*"
 twine = "*"
+tox = "*"
+mypy = "*"

kcpy/checkpoint.py

@@ -1,5 +1,5 @@
 import sqlite3
-
+from typing import Optional
 
 class Checkpoint(object):
     def __init__(self, sqlite_file_path, db_name, consumer_name: str, stream_name: str, shard_id: str) -> None:
@@ -41,7 +41,7 @@ def set(self, seq_no: str) -> None:
         conn.commit()
         conn.close()
 
-    def get(self) -> str:
+    def get(self) -> Optional[str]:
         conn = sqlite3.connect(self.sqlite_file_path)
         c = conn.cursor()
         c.execute(f'SELECT seq_no FROM {self.db_name} '
@@ -54,6 +54,8 @@ def get(self) -> str:
 
         if row:
             return row[0]
+        else:
+            return None
 
     def reset(self) -> None:
         conn = sqlite3.connect(self.sqlite_file_path)

kcpy/core.py

@@ -1,7 +1,7 @@
 import boto3
 import time
 from multiprocessing import Process, Queue
-from typing import Optional
+from typing import Optional, Dict
 import uuid
 
 from .checkpoint import Checkpoint
@@ -57,7 +57,7 @@ class ShardConsumerProcess(Process):
     def __init__(self, stream_name, shard_id, options, checkpoint: Optional[Checkpoint] = None):
         Process.__init__(self)
         self.consumer = ShardConsumer(stream_name, shard_id, options, checkpoint)
-        self.queue = Queue()
+        self.queue = Queue()  # type: Queue
 
     def run(self):
         for record in self.consumer:
@@ -87,7 +87,7 @@ def __init__(self,
         self.stream_name = stream_name
         self.options = options
         self.client = boto3.client('kinesis', **self.options)
-        self.processes = {}
+        self.processes = {}  # type: Dict[str, ShardConsumerProcess]
         self.sleep_time = self.DEFAULT_SLEEP_TIME
         self.enable_checkpoint = checkpoint
 

requirements/default.txt

@@ -0,0 +1 @@
+boto3>=1.9

requirements/dist.txt

@@ -0,0 +1,5 @@
+twine>=1.12.1
+bumpversion>=0.5.3
+flake8>=3.6.0
+tox>=3.5.3
+mypy>=0.641

requirements/test.txt

@@ -0,0 +1,3 @@
+pytest>=4.0.1
+faker>=1.0.0
+moto>=1.3.7

tox.ini

@@ -0,0 +1,24 @@
+[tox]
+envlist = py37,py36,py35,flake8,typecheck
+
+[testenv]
+deps=
+    -r{toxinidir}/requirements/default.txt
+    -r{toxinidir}/requirements/test.txt
+    -r{toxinidir}/requirements/dist.txt
+sitepackages = False
+recreate = False
+commands = py.test -xv
+
+basepython =
+    py37,flake8,typecheck: python3.7
+    py36: python3.6
+    py35: python3.5
+
+[testenv:flake8]
+commands =
+    flake8 {toxinidir}/kcpy
+
+[testenv:typecheck]
+commands =
+    mypy --ignore-missing-imports -p kcpy