Added basic tests, via tox and CI via Travis

.gitignore

@@ -3,3 +3,4 @@ build/
 *.egg-info/
 __pycache__/
 venv/
+.tox/

.travis.yml

@@ -0,0 +1,25 @@
+sudo: false
+dist: xenial
+language: python
+install:
+    - pip install tox
+
+script:
+    - tox -e $TOXENV
+
+matrix:
+  fast_finish: true
+  include:
+    # Python version is just for the look on travis.
+    - python: 2.7
+      env: TOXENV=py27
+
+    - python: 3.5
+      env: TOXENV=py35
+
+    - python: 3.6
+      env: TOXENV=py36
+
+    - python: 3.7
+      env: TOXENV=py37
+      sudo: true

CHANGELOG.md

@@ -5,6 +5,8 @@
 * Added a ``--check-only`` argument to ``download.py`` to display the expiration dates of the files currently on disk.
 * Enable computation of the expiration date of the BSP file(s) on disk (requires to install the local repository using the [dev] option / See README for more information).
 * Dropped compatibility with Python 3.3 and 3.4, as skyfield did.
+* Added basic tests for the ``get_skyfield_data_path`` function using `tox`.
+* Added automated tests through Travis CI.
 
 ## 0.0.2 (2019-08-23)
 

Makefile

@@ -6,7 +6,8 @@ help:
 	@echo " * clean: remove all skyfield data from data directory."
 	@echo " * package: build python source package."
 	@echo ""
-	@echo " * install-dev: Install the requirements to execute download.py"
+	@echo " * install-dev: Install the requirements to switch to dev mode."
+	@echo " * test: Run tests using tox."
 
 download:
 	python3 download.py
@@ -19,3 +20,6 @@ package:
 
 install-dev:
 	pip install -e .[dev]
+
+test:
+	tox

setup.cfg

@@ -36,6 +36,12 @@ setup_requires =
 dev =
     jplephem
     numpy
+    tox
+tests =
+    pytest
+    skyfield
+    mock
+    # ipdb
 
 [bdist_wheel]
 universal = 1

tests/test_get_path.py

@@ -0,0 +1,18 @@
+import mock
+from skyfield_data import get_skyfield_data_path
+from skyfield.api import Loader
+
+
+def test_load_no_cache(tmpdir):
+    with mock.patch('jplephem.spk.SPK.open'):  # avoid naughty side-effects
+        with mock.patch('skyfield.iokit.download') as download_patched:
+            load = Loader(tmpdir.dirname)
+            load('de421.bsp')
+    assert download_patched.call_count == 1
+
+
+@mock.patch('skyfield.iokit.download')
+def test_load_using_cache(download_patched):
+    load = Loader(get_skyfield_data_path())
+    load('de421.bsp')
+    assert download_patched.call_count == 0

tox.ini

@@ -0,0 +1,14 @@
+[tox]
+envlist = py27,py35,py36,py37
+
+
+[testenv]
+commands =
+    pytest -s
+deps =
+    .[tests]
+
+
+[testenv:py33]
+deps = .
+commands = pip freeze -l