Merge pull request #18 from paritytech/td-format

Add 0x when printing hex values.

src/hash_tests.rs

@@ -0,0 +1,20 @@
+use ethereum_types::{U128, H128};
+
+#[test]
+fn should_format_and_debug_correctly() {
+    let test = |x: usize, hex: &'static str, display: &'static str| {
+		let hash = H128::from(U128::from(x));
+        assert_eq!(format!("{}", hash), format!("0x{}", display));
+        assert_eq!(format!("{:?}", hash), format!("0x{}", hex));
+        assert_eq!(format!("{:x}", hash), hex);
+    };
+
+    test(0x1, "00000000000000000000000000000001", "0000…0001");
+    test(0xf, "0000000000000000000000000000000f", "0000…000f");
+    test(0x10, "00000000000000000000000000000010", "0000…0010");
+    test(0xff, "000000000000000000000000000000ff", "0000…00ff");
+    test(0x100, "00000000000000000000000000000100", "0000…0100");
+    test(0xfff, "00000000000000000000000000000fff", "0000…0fff");
+    test(0x1000, "00000000000000000000000000001000", "0000…1000");
+}
+

src/lib.rs

@@ -13,6 +13,8 @@ extern crate quickcheck;
 #[cfg(test)]
 extern crate serde_json;
 
+#[cfg(test)]
+pub mod hash_tests;
 #[cfg(test)]
 pub mod uint_tests;
 #[cfg(test)]

src/uint_tests.rs

@@ -254,8 +254,9 @@ fn uint256_pow_overflow_panic() {
 
 #[test]
 fn should_format_and_debug_correctly() {
-    let test = |x: usize, hex: &'static str, dbg: &'static str| {
-        assert_eq!(format!("{:?}", U256::from(x)), dbg);
+    let test = |x: usize, hex: &'static str, display: &'static str| {
+        assert_eq!(format!("{}", U256::from(x)), display);
+        assert_eq!(format!("{:?}", U256::from(x)), format!("0x{}", hex));
         assert_eq!(format!("{:x}", U256::from(x)), hex);
     };