From e2c97a365659013ead20a4cc2d7720aafb8d7b12 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Drwi=C4=99ga?= <tomusdrw@gmail.com>
Date: Fri, 10 Nov 2017 21:45:23 +0100
Subject: [PATCH] Add tests for invalid cases.

---
 substrate/primitives/src/hash.rs | 10 ++++++++++
 substrate/primitives/src/uint.rs | 20 +++++++++++++++++++-
 substrate/serializer/src/lib.rs  |  2 +-
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/substrate/primitives/src/hash.rs b/substrate/primitives/src/hash.rs
index 144655f0af..788a395f0e 100644
--- a/substrate/primitives/src/hash.rs
+++ b/substrate/primitives/src/hash.rs
@@ -112,4 +112,14 @@ mod tests {
 			assert_eq!(number, ser::from_str(&format!("{:?}", expected)).unwrap());
 		}
 	}
+
+	#[test]
+	fn test_invalid() {
+		assert!(ser::from_str::<H256>("\"0x000000000000000000000000000000000000000000000000000000000000000\"").unwrap_err().is_data());
+		assert!(ser::from_str::<H256>("\"0x000000000000000000000000000000000000000000000000000000000000000g\"").unwrap_err().is_data());
+		assert!(ser::from_str::<H256>("\"0x00000000000000000000000000000000000000000000000000000000000000000\"").unwrap_err().is_data());
+		assert!(ser::from_str::<H256>("\"\"").unwrap_err().is_data());
+		assert!(ser::from_str::<H256>("\"0\"").unwrap_err().is_data());
+		assert!(ser::from_str::<H256>("\"10\"").unwrap_err().is_data());
+	}
 }
diff --git a/substrate/primitives/src/uint.rs b/substrate/primitives/src/uint.rs
index 95714b74d4..305523fe71 100644
--- a/substrate/primitives/src/uint.rs
+++ b/substrate/primitives/src/uint.rs
@@ -45,7 +45,7 @@ macro_rules! impl_serde {
 					}
 
 					fn visit_str<E: de::Error>(self, v: &str) -> Result<Self::Value, E> {
-						if v.len() < 2  || &v[0..2] != "0x" {
+						if v.len() < 3  || &v[0..2] != "0x" {
 							return Err(E::custom("prefix is missing"))
 						}
 
@@ -104,10 +104,28 @@ mod tests {
 					assert_eq!(format!("{:?}", expected), ser::to_string_pretty(&number));
 					assert_eq!(number, ser::from_str(&format!("{:?}", expected)).unwrap());
 				}
+
+				// Invalid examples
+				assert!(ser::from_str::<$name>("\"0x\"").unwrap_err().is_data());
+				assert!(ser::from_str::<$name>("\"0xg\"").unwrap_err().is_data());
+				assert!(ser::from_str::<$name>("\"\"").unwrap_err().is_data());
+				assert!(ser::from_str::<$name>("\"10\"").unwrap_err().is_data());
+				assert!(ser::from_str::<$name>("\"0\"").unwrap_err().is_data());
 			}
 		}
 	}
 
 	test!(U256, test_u256);
 	test!(U512, test_u512);
+
+	#[test]
+	fn test_large_values() {
+		assert_eq!(
+			ser::to_string_pretty(&!U256::zero()),
+			"\"0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\""
+		);
+		assert!(
+			ser::from_str::<U256>("\"0x1ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\"").unwrap_err().is_data()
+		);
+	}
 }
diff --git a/substrate/serializer/src/lib.rs b/substrate/serializer/src/lib.rs
index 56b9e71257..9660f95f71 100644
--- a/substrate/serializer/src/lib.rs
+++ b/substrate/serializer/src/lib.rs
@@ -24,7 +24,7 @@
 extern crate serde;
 extern crate serde_json;
 
-pub use serde_json::{from_str, from_slice, from_reader, Result};
+pub use serde_json::{from_str, from_slice, from_reader, Result, Error};
 
 const PROOF: &str = "Serializers are infallible; qed";