1 files changed, 60 insertions, 0 deletions
diff --git a/tests/test_filter.py b/tests/test_filter.py
new file mode 100644
index 0000000..e47b3b5
--- /dev/null
+++ b/tests/test_filter.py
@@ -0,0 +1,60 @@
+import pytest
+
+from prompt_toolkit.filters import Always, Condition, Filter, Never, to_filter
+
+
+def test_never():
+    assert not Never()()
+
+
+def test_always():
+    assert Always()()
+
+
+def test_invert():
+    assert not (~Always())()
+    assert ~Never()()
+
+    c = ~Condition(lambda: False)
+    assert c()
+
+
+def test_or():
+    for a in (True, False):
+        for b in (True, False):
+            c1 = Condition(lambda: a)
+            c2 = Condition(lambda: b)
+            c3 = c1 | c2
+
+            assert isinstance(c3, Filter)
+            assert c3() == a or b
+
+
+def test_and():
+    for a in (True, False):
+        for b in (True, False):
+            c1 = Condition(lambda: a)
+            c2 = Condition(lambda: b)
+            c3 = c1 & c2
+
+            assert isinstance(c3, Filter)
+            assert c3() == (a and b)
+
+
+def test_to_filter():
+    f1 = to_filter(True)
+    f2 = to_filter(False)
+    f3 = to_filter(Condition(lambda: True))
+    f4 = to_filter(Condition(lambda: False))
+
+    assert isinstance(f1, Filter)
+    assert isinstance(f2, Filter)
+    assert isinstance(f3, Filter)
+    assert isinstance(f4, Filter)
+    assert f1()
+    assert not f2()
+    assert f3()
+    assert not f4()
+
+    with pytest.raises(TypeError):
+        to_filter(4)