add new test module for the public API

tests/api.TestCase

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+
+import inspect
+import os
+import sys
+import unittest
+from unittest import mock
+
+localmodule = os.path.realpath(
+    os.path.join(os.path.dirname(inspect.getfile(inspect.currentframe())), '..')
+)
+print('localmodule: ' + localmodule)
+if localmodule not in sys.path:
+    sys.path.insert(0, localmodule)
+
+import fdroidserver
+
+
+class ApiTest(unittest.TestCase):
+    """Test the public API in the base "fdroidserver" module
+
+    This is mostly a smokecheck to make sure the public API as
+    declared in fdroidserver/__init__.py is working.  The functions
+    are all implemented in other modules, with their own tests.
+
+    """
+
+    def setUp(self):
+        self.basedir = os.path.join(localmodule, 'tests')
+        os.chdir(self.basedir)
+
+    def test_download_repo_index_no_fingerprint(self):
+        with self.assertRaises(fdroidserver.VerificationException):
+            fdroidserver.download_repo_index("http://example.org")
+
+    @mock.patch('fdroidserver.net.http_get')
+    def test_download_repo_index_url_parsing(self, mock_http_get):
+        """Test whether it is trying to download the right file
+
+        This passes the URL back via the etag return value just as a
+        hack to check which URL was actually attempted.
+
+        """
+        mock_http_get.side_effect = lambda url, etag, timeout: (None, url)
+        repo_url = 'https://example.org/fdroid/repo'
+        index_url = 'https://example.org/fdroid/repo/index-v1.jar'
+        for url in (repo_url, index_url):
+            _ignored, etag_set_to_url = fdroidserver.download_repo_index(
+                url, verify_fingerprint=False
+            )
+            self.assertEqual(index_url, etag_set_to_url)
+
+    @mock.patch('fdroidserver.net.http_get')
+    def test_download_repo_index_v1_url_parsing(self, mock_http_get):
+        """Test whether it is trying to download the right file
+
+        This passes the URL back via the etag return value just as a
+        hack to check which URL was actually attempted.
+
+        """
+        mock_http_get.side_effect = lambda url, etag, timeout: (None, url)
+        repo_url = 'https://example.org/fdroid/repo'
+        index_url = 'https://example.org/fdroid/repo/index-v1.jar'
+        for url in (repo_url, index_url):
+            _ignored, etag_set_to_url = fdroidserver.download_repo_index_v1(
+                url, verify_fingerprint=False
+            )
+            self.assertEqual(index_url, etag_set_to_url)
+
+
+if __name__ == "__main__":
+    newSuite = unittest.TestSuite()
+    newSuite.addTest(unittest.makeSuite(ApiTest))
+    unittest.main(failfast=False)