Introduce static hex and valid signature for block test.

substrate/wasm-runtime/polkadot/src/support/testing.rs

@@ -19,3 +19,46 @@ impl Externalities for TestExternalities {
 
 	fn chain_id(&self) -> u64 { 42 }
 }
+
+pub struct HexDisplay<'a>(&'a [u8]);
+
+impl<'a> HexDisplay<'a> {
+	pub fn from(d: &'a AsBytesRef) -> Self { HexDisplay(d.as_bytes_ref()) }
+}
+
+impl<'a> ::std::fmt::Display for HexDisplay<'a> {
+	fn fmt(&self, fmtr: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
+		for byte in self.0 {
+			try!( fmtr.write_fmt(format_args!("{:02x}", byte)));
+		}
+		Ok(())
+	}
+}
+
+pub trait AsBytesRef {
+	fn as_bytes_ref(&self) -> &[u8];
+}
+
+impl AsBytesRef for [u8] {
+	fn as_bytes_ref(&self) -> &[u8] { &self }
+}
+
+impl<'a> AsBytesRef for &'a[u8] {
+	fn as_bytes_ref(&self) -> &[u8] { self }
+}
+
+impl AsBytesRef for Vec<u8> {
+	fn as_bytes_ref(&self) -> &[u8] { &self[..] }
+}
+
+macro_rules! impl_non_endians {
+	( $( $t:ty ),* ) => { $(
+		impl AsBytesRef for $t {
+			fn as_bytes_ref(&self) -> &[u8] { &self[..] }
+		}
+	)* }
+}
+
+impl_non_endians!([u8; 1], [u8; 2], [u8; 3], [u8; 4], [u8; 5], [u8; 6], [u8; 7], [u8; 8],
+	[u8; 10], [u8; 12], [u8; 14], [u8; 16], [u8; 20], [u8; 24], [u8; 28], [u8; 32], [u8; 40],
+	[u8; 48], [u8; 56], [u8; 64], [u8; 80], [u8; 96], [u8; 112], [u8; 128]);