diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..439f62c
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,62 @@
+define BROWSER_PYSCRIPT
+import os, webbrowser, sys
+
+from urllib.request import pathname2url
+
+webbrowser.open("file://" + pathname2url(os.path.abspath(sys.argv[1])))
+endef
+export BROWSER_PYSCRIPT
+
+BROWSER := python -c "$$BROWSER_PYSCRIPT"
+sources = opendatasets
+
+.PHONY: test format lint unittest coverage pre-commit clean
+clean-build: ## remove build artifacts
+	rm -fr build/
+	rm -fr dist/
+	rm -fr .eggs/
+	find . -name '*.egg-info' -exec rm -fr {} +
+	find . -name '*.egg' -exec rm -f {} +
+
+clean-pyc: ## remove Python file artifacts
+	find . -name '*.pyc' -exec rm -f {} +
+	find . -name '*.pyo' -exec rm -f {} +
+	find . -name '*~' -exec rm -f {} +
+	find . -name '__pycache__' -exec rm -fr {} +
+
+test: lint unittest
+
+format:
+	isort $(sources) tests
+	black $(sources) tests
+
+lint:
+	flake8 $(sources) tests
+	# mypy $(sources) tests
+
+unittest: clean
+	pytest
+
+cov:
+	pytest --cov=$(sources) --cov-branch --cov-report=term-missing tests
+	coverage report -m
+	coverage html
+	$(BROWSER) htmlcov/index.html
+
+pre-commit:
+	pre-commit run --all-files
+
+clean-cache:
+	rm -rf .mypy_cache .pytest_cache
+	rm -rf *.egg-info
+	rm -rf .tox dist site
+	rm -rf coverage.xml .coverage
+	rm -rf output/*.*
+
+clean: clean-build clean-pyc clean-cache
+
+dist: clean
+	poetry build
+
+release: dist ## package and upload a release
+	twine upload dist/*
diff --git a/README.md b/README.md
index 7306283..e8b091e 100644
--- a/README.md
+++ b/README.md
@@ -187,8 +187,12 @@ git clone https://github.com/JovianML/opendatasets.git
 conda create -n opendatasets python=3.5
 conda activate opendatasets
 pip install -r requirements.txt
+pip install -r requirements_dev.txt
 ```
 
 3. Open up the project in VS code and make your changes. Make sure to install the Python Extension for VS Code and select the `opendatasets` conda environment.
 
+### Testing
+
+
 This package is developed and maintained by the [Jovian](https://www.jovian.ai) team.
diff --git a/opendatasets/__init__.py b/opendatasets/__init__.py
index 16ae539..54009e6 100644
--- a/opendatasets/__init__.py
+++ b/opendatasets/__init__.py
@@ -1,9 +1,11 @@
 import importlib
+
+from opendatasets.utils.kaggle_direct import is_kaggle_url
 from opendatasets.utils.network import download_url, is_url
 from opendatasets.utils.googledrive import is_google_drive_url, download_google_drive
 import os
 from opendatasets._version import __version__
-from opendatasets.utils.kaggle_api import download_kaggle_dataset, is_kaggle_url
+from opendatasets.utils.kaggle_api import download_kaggle_dataset
 from opendatasets.utils.archive import extract_archive
 
 
diff --git a/opendatasets/datasets/owid-covid-19-latest/__init__.py b/opendatasets/datasets/owid-covid-19-latest/__init__.py
index e410107..99910f3 100644
--- a/opendatasets/datasets/owid-covid-19-latest/__init__.py
+++ b/opendatasets/datasets/owid-covid-19-latest/__init__.py
@@ -1,8 +1,10 @@
 from opendatasets.utils import download_url
 
+last_updated = 'https://raw.githubusercontent.com/owid/covid-19-data/master/public/data' \
+               '/owid-covid-data-last-updated-timestamp.txt'
 URLs = [
     'https://raw.githubusercontent.com/owid/covid-19-data/master/public/data/owid-covid-data.csv',
-    'https://raw.githubusercontent.com/owid/covid-19-data/master/public/data/owid-covid-data-last-updated-timestamp.txt',
+    last_updated,
     'https://raw.githubusercontent.com/owid/covid-19-data/master/public/data/owid-covid-codebook.csv'
 ]
 
diff --git a/opendatasets/utils/googledrive.py b/opendatasets/utils/googledrive.py
index af76fab..bf49c47 100644
--- a/opendatasets/utils/googledrive.py
+++ b/opendatasets/utils/googledrive.py
@@ -1,12 +1,13 @@
-from opendatasets.utils.network import get_filename_cd
 import os
 import re
 import zipfile
-import cgi  
-from opendatasets.utils.md5 import check_integrity
 from urllib.parse import urlparse
+
 from tqdm import tqdm
 
+from opendatasets.utils.md5 import check_integrity
+from opendatasets.utils.network import get_filename_cd
+
 
 def download_google_drive(url, data_dir):
     print('Downloading from Google Drive (may take a while):', url)
@@ -28,7 +29,8 @@ def download_google_drive(url, data_dir):
 
 
 def is_google_drive_url(url):
-    return url.startswith('https://drive.google.com') or url.startswith('http://drive.google.com') or url.startswith('drive.google.com')
+    return url.startswith('https://drive.google.com') or url.startswith('http://drive.google.com') \
+        or url.startswith('drive.google.com')
 
 
 def _get_google_drive_file_id(url):
@@ -43,6 +45,7 @@ def _get_google_drive_file_id(url):
 
     return match.group("id")
 
+
 def _quota_exceeded(response):
     return "Google Drive - Quota exceeded" in response.text
 
@@ -88,9 +91,9 @@ def download_file_from_google_drive(file_id, root, filename=None, md5=None):
 
         if _quota_exceeded(response):
             msg = (
-                "The daily quota of the file " + filename + " is exceeded and it " +
-                "can't be downloaded. This is a limitation of Google Drive " +
-                "and can only be overcome by trying again later."
+                    "The daily quota of the file " + filename + " is exceeded and it " +
+                    "can't be downloaded. This is a limitation of Google Drive " +
+                    "and can only be overcome by trying again later."
             )
             raise RuntimeError(msg)
 
diff --git a/opendatasets/utils/kaggle_api.py b/opendatasets/utils/kaggle_api.py
index 82361c8..d5e0e02 100644
--- a/opendatasets/utils/kaggle_api.py
+++ b/opendatasets/utils/kaggle_api.py
@@ -1,8 +1,11 @@
+import json
 import os
-from opendatasets.utils.kaggle_direct import get_kaggle_dataset_id, is_kaggle_url
-from opendatasets.utils.archive import extract_archive
+from pathlib import Path
+
 import click
-import json
+
+from opendatasets.utils.archive import extract_archive
+from opendatasets.utils.kaggle_direct import get_kaggle_dataset_id
 
 
 def _get_kaggle_key():
@@ -17,16 +20,20 @@ def _get_kaggle_key():
     return user_input
 
 
-def read_kaggle_creds():
+def read_kaggle_creds(credentials_file: Path | None = None) -> bool:
     try:
-        if os.path.exists('./kaggle.json'):
-            with open('./kaggle.json', 'r') as f:
+        if credentials_file is None:
+            credentials_file = Path('./kaggle.json')
+        if credentials_file.exists():
+            with open(credentials_file, 'r') as f:
                 key = f.read()
                 data = json.loads(key)
                 if 'username' in data and 'key' in data:
                     os.environ['KAGGLE_USERNAME'] = data['username']
                     os.environ['KAGGLE_KEY'] = data['key']
                     return True
+        else:
+            return False
     except Exception:
         return False
 
diff --git a/opendatasets/utils/kaggle_direct.py b/opendatasets/utils/kaggle_direct.py
index b8da598..83a21e1 100644
--- a/opendatasets/utils/kaggle_direct.py
+++ b/opendatasets/utils/kaggle_direct.py
@@ -22,7 +22,7 @@ def get_kaggle_dataset_id(dataset_id_or_url):
     elif not is_url(dataset_id_or_url):
         parts = dataset_id_or_url.split('/')[:2]
     assert len(parts) == 2, 'Invalid Kaggle dataset URL or ID: ' + \
-        dataset_id_or_url
+                            dataset_id_or_url
     return '/'.join(parts)
 
 
@@ -37,10 +37,8 @@ def get_kaggle_download_hash(dataset_id):
 def download_kaggle_dataset(dataset_url, data_dir='.', force=True, dry_run=False):
     dataset_id = get_kaggle_dataset_id(dataset_url)
     print('Kaggle dataset ID: ', dataset_id)
-    raw_dataset_url = ('https://www.kaggle.com/' +
-                       dataset_id +
-                       '/download?resource=download&downloadHash=' +
-                       get_kaggle_download_hash(dataset_id))
+    raw_dataset_url = (f'https://www.kaggle.com/{dataset_id}/download?resource'
+                       f'=download&downloadHash={get_kaggle_download_hash(dataset_id)}')
     folder_name = dataset_id.split('/')[-1]
     archive_name = folder_name + '.zip'
     download_url(raw_dataset_url, root=data_dir,
diff --git a/opendatasets/utils/network.py b/opendatasets/utils/network.py
index 0098eab..2695774 100644
--- a/opendatasets/utils/network.py
+++ b/opendatasets/utils/network.py
@@ -1,33 +1,39 @@
-import os
 import cgi
+import os
 import re
+
 from tqdm import tqdm
+
 from opendatasets.utils.md5 import check_integrity
-import urllib
 
 try:
     import urllib.request as request
+
     urlopen = request.urlopen
 except Exception:
     # For Python 2.7
     import urllib
+
     urlopen = urllib.urlopen
 
 try:
     import urllib.request as request
+
     urlretrieve = request.urlretrieve
 except Exception:
     import urllib
+
     # For Python 2.7
     urlretrieve = urllib.urlretrieve
 
 
 def download_url(url, root, filename=None, md5=None, force=False, dry_run=False):
     """Download a file from a url and place it in root.
+
     Args:
         url (str): URL to download file from
         root (str): Directory to place downloaded file in
-        filename (str, optional): 
+        filename (str, optional): Name of the file
         Name to save the file under. If None, use the basename of the URL
         md5 (str, optional): MD5 checksum of the download. If None, do not check
     """
@@ -40,13 +46,13 @@ def download_url(url, root, filename=None, md5=None, force=False, dry_run=False)
         filename = os.path.basename(url)
     fpath = os.path.join(root, filename)
 
-    if not(os.path.exists(root)):
+    if not (os.path.exists(root)):
         os.makedirs(root)
 
     # check if file is already present locally
     if not force and check_integrity(fpath, md5):
         print('Using downloaded and verified file: ' + fpath)
-    else:   # download the file
+    else:  # download the file
         try:
             print('Downloading ' + url + ' to ' + fpath)
             if not dry_run:
diff --git a/requirements_dev.txt b/requirements_dev.txt
new file mode 100644
index 0000000..a099c77
--- /dev/null
+++ b/requirements_dev.txt
@@ -0,0 +1,3 @@
+pytest==7.2.2
+pytest-mock==3.10.0
+mypy==1.2.0
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..a424b25
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,40 @@
+[flake8]
+max-line-length = 120
+max-complexity = 18
+ignore = E203, E266, W503
+docstring-convention = google
+per-file-ignores = __init__.py:F401
+exclude = .git,
+    __pycache__,
+    setup.py,
+    build,
+    dist,
+    docs,
+    releases,
+    .venv,
+    .tox,
+    .mypy_cache,
+    .pytest_cache,
+    .vscode,
+    .github,
+    # By default test codes will be linted.
+    # tests
+
+[mypy]
+ignore_missing_imports = True
+
+[coverage:run]
+# uncomment the following to omit files during running
+#omit =
+[coverage:report]
+exclude_lines =
+    pragma: no cover
+    def __repr__
+    if self.debug:
+    if settings.DEBUG
+    raise AssertionError
+    raise NotImplementedError
+    if 0:
+    if __name__ == .__main__.:
+    def main
+
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..1c44764
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,9 @@
+from pathlib import Path
+
+import pytest
+
+
+@pytest.fixture(scope='session')
+def fixtures_folder():
+    folder = Path(__file__).parent / 'fixtures'
+    return folder
diff --git a/tests/fixtures/kaggle.json b/tests/fixtures/kaggle.json
new file mode 100644
index 0000000..df2e728
--- /dev/null
+++ b/tests/fixtures/kaggle.json
@@ -0,0 +1 @@
+{"username": "wintersoldier", "key": "adamantium22"}
\ No newline at end of file
diff --git a/tests/utils/__init__.py b/tests/utils/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/utils/test_kaggle_api.py b/tests/utils/test_kaggle_api.py
new file mode 100644
index 0000000..917ddf1
--- /dev/null
+++ b/tests/utils/test_kaggle_api.py
@@ -0,0 +1,46 @@
+import json
+import os
+from pathlib import Path
+
+from opendatasets.utils.kaggle_api import read_kaggle_creds
+
+
+def test_read_kaggle_creds():
+    found = read_kaggle_creds()
+    assert not found
+
+
+def test_read_kaggle_creds_file_found():
+    """Creates a local kaggle credential file and verifies that the credentials are loaded"""
+    credentials_file = Path(__file__).cwd() / 'kaggle.json'
+    credentials_file.unlink(missing_ok=True)
+
+    os.environ['KAGGLE_USERNAME'] = ''
+    os.environ['KAGGLE_KEY'] = ''
+
+    kaggle_data = {'username': 'wolverine', 'key': 'adamantium11'}
+    with open(credentials_file, 'w') as f:
+        json.dump(kaggle_data, f)
+
+    assert credentials_file.exists()
+
+    found = read_kaggle_creds()
+    assert found
+    assert os.environ['KAGGLE_USERNAME'] == kaggle_data['username']
+    assert os.environ['KAGGLE_KEY'] == kaggle_data['key']
+
+    credentials_file.unlink()
+
+
+def test_read_kaggle_creds_custom_credentials(fixtures_folder):
+    credentials_file = fixtures_folder / 'kaggle.json'
+
+    os.environ['KAGGLE_USERNAME'] = ''
+    os.environ['KAGGLE_KEY'] = ''
+
+    assert credentials_file.exists()
+
+    found = read_kaggle_creds(credentials_file=credentials_file)
+    assert found
+    assert os.environ['KAGGLE_USERNAME'] == 'wintersoldier'
+    assert os.environ['KAGGLE_KEY'] == 'adamantium22'