diff --git a/test.py b/test.py
new file mode 100644
--- /dev/null
+++ b/test.py
@@ -0,0 +1,54 @@
+from unittest import TestCase
+
+from rank_progress import RankTracker
+
+
+class TestRankTracker(TestCase):
+	def test_no_change(self):
+		t = RankTracker(1945)  # 2k
+		for r in [1945, 1949, 1900, 1850]:
+			self.assertFalse(t.update(r), r)
+
+	def test_promotion(self):
+		# basic
+		t = RankTracker(1945)
+		for (rating, rank) in [(1950, "1k"), (1945, False), (2000, False), (2049, False), (2051, "1d")]:
+			self.assertEqual(t.update(rating), rank, (rating, rank))
+
+		# 2+ ranks leaps
+
+		# limited when pushing the personal best
+		self.skipTest("not yet implemented")
+		t = RankTracker(1100)
+		self.assertEqual(t.update(1299), "9k")
+		self.assertEqual(t.update(1250), "8k")
+		self.assertEqual(t.update(1500), "6k")
+
+		# regular below the personal best
+		t = RankTracker(1201)  # 9k
+		t.update(1000)
+		t.update(900)
+		t.update(849)  # 11k
+		self.assertEqual(t.update(1250), "8k")
+
+	def test_demotion(self):
+		t = RankTracker(2069)
+		self.assertEqual(t.update(1995), "1k")
+
+		t = RankTracker(1590)
+		self.assertEqual(t.update(1387), "7k")
+
+		t = RankTracker(1087)
+		self.assertFalse(t.update(995))
+		self.assertEqual(t.update(940), "11k")
+
+	def test_edges_cases(self):
+		t = RankTracker(-900)
+		self.assertEqual(t.rank, "30k")
+		with self.assertRaises(AssertionError):
+			t.update(-901)
+
+		t = RankTracker(2700)
+		self.assertEqual(t.rank, "7d")
+		self.assertFalse(t.update(2750))
+		self.assertFalse(t.update(2800))