Merge pull request #52 from cyberthirst/fork/charles-cooper/feat/impr…

…ove-event-kwargs-recommendation

add tests for event kwargs hint

tests/functional/syntax/test_event_kwarg_hint.py

@@ -0,0 +1,48 @@
+import warnings
+
+import pytest
+
+from vyper.compiler import compile_code
+
+
+def test_event_kwarg_hint():
+    code = """
+from ethereum.ercs import IERC20
+
+def foo():
+    log IERC20.Transfer(msg.sender, msg.sender, 123)
+    """
+
+    with warnings.catch_warnings(record=True) as w:
+        assert compile_code(code) is not None
+
+    expected = "Instantiating events with positional arguments is deprecated "
+    expected += "as of v0.4.1 and will be disallowed in a future release. "
+    expected += "Use kwargs instead e.g.:\n"
+    expected += "```\nIERC20.Transfer(sender=msg.sender, receiver=msg.sender, value=123)\n```"
+
+    assert len(w) == 1, [s.message for s in w]
+    assert str(w[0].message).startswith(expected)
+
+
+# https://github.com/vyperlang/vyper/pull/4275#issuecomment-2394910693
+# explains the xfail
+@pytest.mark.xfail(raises=AssertionError)
+def test_event_hint_single_char_argument():
+    code = """
+from ethereum.ercs import IERC20
+
+def foo():
+    log IERC20.Transfer(msg.sender, msg.sender, 1)
+    """
+
+    with warnings.catch_warnings(record=True) as w:
+        assert compile_code(code) is not None
+
+    expected = "Instantiating events with positional arguments is deprecated "
+    expected += "as of v0.4.1 and will be disallowed in a future release. "
+    expected += "Use kwargs instead e.g.:\n"
+    expected += "```\nIERC20.Transfer(sender=msg.sender, receiver=msg.sender, value=1)\n```"
+
+    assert len(w) == 1, [s.message for s in w]
+    assert str(w[0].message).startswith(expected)