3 files changed, 34 insertions, 0 deletions
diff --git a/tests/basics/exception1.py b/tests/basics/exception1.py
index d83764cb9..a0ca8a74e 100644
--- a/tests/basics/exception1.py
+++ b/tests/basics/exception1.py
@@ -1,3 +1,5 @@
+# test basic properties of exceptions
+
 print(repr(IndexError()))
 print(str(IndexError()))
 
@@ -12,3 +14,6 @@ s = StopIteration()
 print(s.value)
 s = StopIteration(1, 2, 3)
 print(s.value)
+
+print(OSError().errno)
+print(OSError(1, "msg").errno)
diff --git a/tests/basics/subclass_native3.py b/tests/basics/subclass_native3.py
index 6745b77bb..ac5aabfed 100644
--- a/tests/basics/subclass_native3.py
+++ b/tests/basics/subclass_native3.py
@@ -1,6 +1,10 @@
+# test subclassing a native exception
+
+
 class MyExc(Exception):
     pass
 
+
 e = MyExc(100, "Some error")
 print(e)
 print(repr(e))
@@ -20,3 +24,19 @@ try:
     raise MyExc("Some error2")
 except:
     print("Caught user exception")
+
+
+class MyStopIteration(StopIteration):
+    pass
+
+
+print(MyStopIteration().value)
+print(MyStopIteration(1).value)
+
+
+class MyOSError(OSError):
+    pass
+
+
+print(MyOSError().errno)
+print(MyOSError(1, "msg").errno)
diff --git a/tests/cpydiff/types_exception_attrs.py b/tests/cpydiff/types_exception_attrs.py
new file mode 100644
index 000000000..ad72b62a6
--- /dev/null
+++ b/tests/cpydiff/types_exception_attrs.py
@@ -0,0 +1,9 @@
+"""
+categories: Types,Exception
+description: All exceptions have readable ``value`` and ``errno`` attributes, not just ``StopIteration`` and ``OSError``.
+cause: MicroPython is optimised to reduce code size.
+workaround: Only use ``value`` on ``StopIteration`` exceptions, and ``errno`` on ``OSError`` exceptions.  Do not use or rely on these attributes on other exceptions.
+"""
+e = Exception(1)
+print(e.value)
+print(e.errno)