1 files changed, 149 insertions, 0 deletions
diff --git a/tests/test_nativetypes.py b/tests/test_nativetypes.py
new file mode 100644
index 00000000..22581813
--- /dev/null
+++ b/tests/test_nativetypes.py
@@ -0,0 +1,149 @@
+import math
+
+import pytest
+
+from jinja2.exceptions import UndefinedError
+from jinja2.nativetypes import NativeEnvironment
+from jinja2.nativetypes import NativeTemplate
+from jinja2.runtime import Undefined
+
+
+@pytest.fixture
+def env():
+    return NativeEnvironment()
+
+
+def test_is_defined_native_return(env):
+    t = env.from_string("{{ missing is defined }}")
+    assert not t.render()
+
+
+def test_undefined_native_return(env):
+    t = env.from_string("{{ missing }}")
+    assert isinstance(t.render(), Undefined)
+
+
+def test_adding_undefined_native_return(env):
+    t = env.from_string("{{ 3 + missing }}")
+
+    with pytest.raises(UndefinedError):
+        t.render()
+
+
+def test_cast_int(env):
+    t = env.from_string("{{ value|int }}")
+    result = t.render(value="3")
+    assert isinstance(result, int)
+    assert result == 3
+
+
+def test_list_add(env):
+    t = env.from_string("{{ a + b }}")
+    result = t.render(a=["a", "b"], b=["c", "d"])
+    assert isinstance(result, list)
+    assert result == ["a", "b", "c", "d"]
+
+
+def test_multi_expression_add(env):
+    t = env.from_string("{{ a }} + {{ b }}")
+    result = t.render(a=["a", "b"], b=["c", "d"])
+    assert not isinstance(result, list)
+    assert result == "['a', 'b'] + ['c', 'd']"
+
+
+def test_loops(env):
+    t = env.from_string("{% for x in value %}{{ x }}{% endfor %}")
+    result = t.render(value=["a", "b", "c", "d"])
+    assert isinstance(result, str)
+    assert result == "abcd"
+
+
+def test_loops_with_ints(env):
+    t = env.from_string("{% for x in value %}{{ x }}{% endfor %}")
+    result = t.render(value=[1, 2, 3, 4])
+    assert isinstance(result, int)
+    assert result == 1234
+
+
+def test_loop_look_alike(env):
+    t = env.from_string("{% for x in value %}{{ x }}{% endfor %}")
+    result = t.render(value=[1])
+    assert isinstance(result, int)
+    assert result == 1
+
+
+@pytest.mark.parametrize(
+    ("source", "expect"),
+    (
+        ("{{ value }}", True),
+        ("{{ value }}", False),
+        ("{{ 1 == 1 }}", True),
+        ("{{ 2 + 2 == 5 }}", False),
+        ("{{ None is none }}", True),
+        ("{{ '' == None }}", False),
+    ),
+)
+def test_booleans(env, source, expect):
+    t = env.from_string(source)
+    result = t.render(value=expect)
+    assert isinstance(result, bool)
+    assert result is expect
+
+
+def test_variable_dunder(env):
+    t = env.from_string("{{ x.__class__ }}")
+    result = t.render(x=True)
+    assert isinstance(result, type)
+
+
+def test_constant_dunder(env):
+    t = env.from_string("{{ true.__class__ }}")
+    result = t.render()
+    assert isinstance(result, type)
+
+
+def test_constant_dunder_to_string(env):
+    t = env.from_string("{{ true.__class__|string }}")
+    result = t.render()
+    assert not isinstance(result, type)
+    assert result in {"<type 'bool'>", "<class 'bool'>"}
+
+
+def test_string_literal_var(env):
+    t = env.from_string("[{{ 'all' }}]")
+    result = t.render()
+    assert isinstance(result, str)
+    assert result == "[all]"
+
+
+def test_string_top_level(env):
+    t = env.from_string("'Jinja'")
+    result = t.render()
+    assert result == "Jinja"
+
+
+def test_tuple_of_variable_strings(env):
+    t = env.from_string("'{{ a }}', 'data', '{{ b }}', b'{{ c }}'")
+    result = t.render(a=1, b=2, c="bytes")
+    assert isinstance(result, tuple)
+    assert result == ("1", "data", "2", b"bytes")
+
+
+def test_concat_strings_with_quotes(env):
+    t = env.from_string("--host='{{ host }}' --user \"{{ user }}\"")
+    result = t.render(host="localhost", user="Jinja")
+    assert result == "--host='localhost' --user \"Jinja\""
+
+
+def test_no_intermediate_eval(env):
+    t = env.from_string("0.000{{ a }}")
+    result = t.render(a=7)
+    assert isinstance(result, float)
+    # If intermediate eval happened, 0.000 would render 0.0, then 7
+    # would be appended, resulting in 0.07.
+    assert math.isclose(result, 0.0007)
+
+
+def test_spontaneous_env():
+    t = NativeTemplate("{{ true }}")
+    assert isinstance(t.environment, NativeEnvironment)