copy test_database from magic-wormhole package

disable the upgrader test for now, since we only have the one schema version

src/wormhole_transit_relay/test/test_database.py

@@ -0,0 +1,61 @@
+from __future__ import print_function, unicode_literals
+import os
+from twisted.python import filepath
+from twisted.trial import unittest
+from .. import database
+from ..database import get_db, TARGET_VERSION, dump_db
+
+class Get(unittest.TestCase):
+    def test_create_default(self):
+        db_url = ":memory:"
+        db = get_db(db_url)
+        rows = db.execute("SELECT * FROM version").fetchall()
+        self.assertEqual(len(rows), 1)
+        self.assertEqual(rows[0]["version"], TARGET_VERSION)
+
+    def test_failed_create_allows_subsequent_create(self):
+        patch = self.patch(database, "get_schema", lambda version: b"this is a broken schema")
+        dbfile = filepath.FilePath(self.mktemp())
+        self.assertRaises(Exception, lambda: get_db(dbfile.path))
+        patch.restore()
+        get_db(dbfile.path)
+
+    def OFF_test_upgrade(self): # disabled until we add a v2 schema
+        basedir = self.mktemp()
+        os.mkdir(basedir)
+        fn = os.path.join(basedir, "upgrade.db")
+        self.assertNotEqual(TARGET_VERSION, 2)
+
+        # create an old-version DB in a file
+        db = get_db(fn, 2)
+        rows = db.execute("SELECT * FROM version").fetchall()
+        self.assertEqual(len(rows), 1)
+        self.assertEqual(rows[0]["version"], 2)
+        del db
+
+        # then upgrade the file to the latest version
+        dbA = get_db(fn, TARGET_VERSION)
+        rows = dbA.execute("SELECT * FROM version").fetchall()
+        self.assertEqual(len(rows), 1)
+        self.assertEqual(rows[0]["version"], TARGET_VERSION)
+        dbA_text = dump_db(dbA)
+        del dbA
+
+        # make sure the upgrades got committed to disk
+        dbB = get_db(fn, TARGET_VERSION)
+        dbB_text = dump_db(dbB)
+        del dbB
+        self.assertEqual(dbA_text, dbB_text)
+
+        # The upgraded schema should be equivalent to that of a new DB.
+        # However a text dump will differ because ALTER TABLE always appends
+        # the new column to the end of a table, whereas our schema puts it
+        # somewhere in the middle (wherever it fits naturally). Also ALTER
+        # TABLE doesn't include comments.
+        if False:
+            latest_db = get_db(":memory:", TARGET_VERSION)
+            latest_text = dump_db(latest_db)
+            with open("up.sql","w") as f: f.write(dbA_text)
+            with open("new.sql","w") as f: f.write(latest_text)
+            # check with "diff -u _trial_temp/up.sql _trial_temp/new.sql"
+            self.assertEqual(dbA_text, latest_text)