Move types to more appropriate files (#10638)

sdk/src/decode_error.rs

@@ -0,0 +1,38 @@
+use num_traits::FromPrimitive;
+
+/// Allows customer errors to be decoded back to their original enum
+pub trait DecodeError<E> {
+    fn decode_custom_error_to_enum(custom: u32) -> Option<E>
+    where
+        E: FromPrimitive,
+    {
+        E::from_u32(custom)
+    }
+    fn type_of() -> &'static str;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use num_derive::FromPrimitive;
+
+    #[test]
+    fn test_decode_custom_error_to_enum() {
+        #[derive(Debug, FromPrimitive, PartialEq)]
+        enum TestEnum {
+            A,
+            B,
+            C,
+        }
+        impl<T> DecodeError<T> for TestEnum {
+            fn type_of() -> &'static str {
+                "TestEnum"
+            }
+        }
+        assert_eq!(TestEnum::decode_custom_error_to_enum(0), Some(TestEnum::A));
+        assert_eq!(TestEnum::decode_custom_error_to_enum(1), Some(TestEnum::B));
+        assert_eq!(TestEnum::decode_custom_error_to_enum(2), Some(TestEnum::C));
+        let option: Option<TestEnum> = TestEnum::decode_custom_error_to_enum(3);
+        assert_eq!(option, None);
+    }
+}