Add download tests

Author: rumackaaron

changehc/tests/test_download_ftp_files.py

@@ -0,0 +1,63 @@
+# standard
+import pytest
+import mock
+from datetime import datetime as dt
+from datetime import timedelta
+
+# first party
+from delphi_changehc.download_ftp_files import *
+
+class TestDownloadFTPFiles:
+
+    class MockSFTP:
+
+        # Mocks an SFTP connection
+        def __init__(self, attrs):
+            self.attrs = attrs
+            self.num_gets = 0
+
+        # Attrs are modified time and filename
+        def listdir_attr(self):
+            return self.attrs
+
+        # Don't download anything, just note that method was called
+        def get(self, infile, outfile, callback=None):
+            self.num_gets += 1
+            return
+
+
+    class FileAttr:
+
+        def __init__(self, time, name):
+            self.st_mtime = time
+            self.filename = name
+
+
+    @mock.patch("os.path")
+    def test_get_files(self, mock_path):
+
+        # When one new file is present, one file is downloaded
+        one_new = self.MockSFTP([self.FileAttr(dt.timestamp(dt.now()-timedelta(minutes=1)),"foo")])
+        get_files_from_dir(one_new, "")
+        assert one_new.num_gets == 1
+
+        # When one new file and one old file are present, one file is downloaded
+        one_new_one_old = self.MockSFTP([self.FileAttr(dt.timestamp(dt.now()-timedelta(minutes=1)),"foo"),
+                                         self.FileAttr(dt.timestamp(dt.now()-timedelta(days=10)),"foo")])
+        get_files_from_dir(one_new_one_old, "")
+        assert one_new_one_old.num_gets == 1
+
+        # When three new files are present, AssertionError
+        new_file1 = self.FileAttr(dt.timestamp(dt.now()-timedelta(minutes=1)),"foo1")
+        new_file2 = self.FileAttr(dt.timestamp(dt.now()-timedelta(minutes=1)),"foo2")
+        new_file3 = self.FileAttr(dt.timestamp(dt.now()-timedelta(minutes=1)),"foo3")
+        three_new = self.MockSFTP([new_file1, new_file2, new_file3])
+        with pytest.raises(AssertionError):
+            get_files_from_dir(three_new,"")
+
+        # When the file already exists, no files are downloaded
+        mock_path.exists.return_value = True
+        one_exists = self.MockSFTP([new_file1])
+        get_files_from_dir(one_new, "")
+        assert one_exists.num_gets == 0
+