1 files changed, 23 insertions, 0 deletions
diff --git a/tests/functional/d/deprecated_lambda.py b/tests/functional/d/deprecated_lambda.py
new file mode 100644
index 000000000..92a2e84ab
--- /dev/null
+++ b/tests/functional/d/deprecated_lambda.py
@@ -0,0 +1,23 @@
+# pylint: disable=missing-docstring,invalid-name,no-absolute-import
+
+import functools
+
+# Don't do this, use a comprehension instead.
+assert map(lambda x: x*2, [1, 2, 3]) == [2, 4, 6] # [deprecated-lambda]
+
+assert filter(lambda x: x != 1, [1, 2, 3]) == [2, 3] # [deprecated-lambda]
+
+# It's still ok to use map and filter with anything but an inline lambda.
+double = lambda x: x * 2
+assert map(double, [1, 2, 3]) == [2, 4, 6]
+
+# It's also ok to pass lambdas to other functions.
+assert functools.reduce(lambda x, y: x * y, [1, 2, 3, 4]) == 24
+
+# Or to an undefined function or one with varargs
+def f(*a):
+    return len(a)
+
+f(lambda x, y: x + y, [1, 2, 3])
+
+undefined_function(lambda: 2)  # pylint: disable=undefined-variable