trezor: allow expiring cached passphrase

libagent/tests/test_util.py

@@ -121,3 +121,26 @@ def test_assuan_serialize():
     assert util.assuan_serialize(b'') == b''
     assert util.assuan_serialize(b'123\n456') == b'123%0A456'
     assert util.assuan_serialize(b'\r\n') == b'%0D%0A'
+
+
+def test_cache():
+    timer = mock.Mock(side_effect=range(7))
+    c = util.ExpiringCache(seconds=2, timer=timer)  # t=0
+    assert c.get() is None                          # t=1
+    obj = 'foo'
+    c.set(obj)                                      # t=2
+    assert c.get() is obj                           # t=3
+    assert c.get() is obj                           # t=4
+    assert c.get() is None                          # t=5
+    assert c.get() is None                          # t=6
+
+
+def test_cache_inf():
+    timer = mock.Mock(side_effect=range(6))
+    c = util.ExpiringCache(seconds=float('inf'), timer=timer)
+    obj = 'foo'
+    c.set(obj)
+    assert c.get() is obj
+    assert c.get() is obj
+    assert c.get() is obj
+    assert c.get() is obj