Transaction eras (#758)

* Initial groundwork

* A mess.

* Integrate

* Fix tests

* Unit tests

* Tests for unchecked_extrisnic

* fix tab

* Improve binary format.

* fix tests

* Rename extrinsic-pool -> transaction-pool

Closes #770

* Implement unimplemented.

* typo

substrate/core/sr-primitives/src/generic/checked_extrinsic.rs

@@ -25,10 +25,9 @@ use traits::{self, Member, SimpleArithmetic, MaybeDisplay};
 #[derive(PartialEq, Eq, Clone)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
 pub struct CheckedExtrinsic<AccountId, Index, Call> {
-	/// Who this purports to be from, if anyone (note this is not a signature).
-	pub signed: Option<AccountId>,
-	/// The number of extrinsics have come before from the same signer.
-	pub index: Index,
+	/// Who this purports to be from and the number of extrinsics have come before
+	/// from the same signer, if anyone (note this is not a signature).
+	pub signed: Option<(AccountId, Index)>,
 	/// The function that should be called.
 	pub function: Call,
 }
@@ -44,15 +43,15 @@ where
 	type AccountId = AccountId;
 	type Call = Call;
 
-	fn index(&self) -> &Self::Index {
-		&self.index
+	fn index(&self) -> Option<&Self::Index> {
+		self.signed.as_ref().map(|x| &x.1)
 	}
 
 	fn sender(&self) -> Option<&Self::AccountId> {
-		self.signed.as_ref()
+		self.signed.as_ref().map(|x| &x.0)
 	}
 
 	fn deconstruct(self) -> (Self::Call, Option<Self::AccountId>) {
-		(self.function, self.signed)
+		(self.function, self.signed.map(|x| x.0))
 	}
 }

substrate/core/sr-primitives/src/generic/era.rs

@@ -0,0 +1,192 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Generic implementation of an unchecked (pre-verification) extrinsic.
+
+use codec::{Decode, Encode, Input, Output};
+
+pub type Period = u64;
+pub type Phase = u64;
+
+/// An era to describe the longevity of a transaction.
+#[derive(PartialEq, Eq, Clone, Copy)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
+pub enum Era {
+	/// The transaction is valid forever. The genesis hash must be present in the signed content.
+	Immortal,
+
+	/// Period and phase are encoded:
+	/// - The period of validity from the block hash found in the signing material.
+	/// - The phase in the period that this transaction's lifetime begins (and, importantly,
+	/// implies which block hash is included in the signature material). If the `period` is
+	/// greater than 1 << 12, then it will be a factor of the times greater than 1<<12 that
+	/// `period` is.
+	Mortal(Period, Phase),
+}
+
+/*
+E.g. with period == 4:
+0         10        20        30        40
+0123456789012345678901234567890123456789012
+             |...|
+   authored -/   \- expiry
+phase = 1
+n = Q(current - phase, period) + phase
+*/
+impl Era {
+	/// Create a new era based on a period (which should be a power of two between 4 and 65536 inclusive)
+	/// and a block number on which it should start (or, for long periods, be shortly after the start).
+	pub fn mortal(period: u64, current: u64) -> Self {
+		let period = period.checked_next_power_of_two()
+			.unwrap_or(1 << 16)
+			.max(4)
+			.min(1 << 16);
+		let phase = current % period;
+		let quantize_factor = (period >> 12).max(1);
+		let quantized_phase = phase / quantize_factor * quantize_factor;
+
+		Era::Mortal(period, quantized_phase)
+	}
+
+	/// Create an "immortal" transaction. 
+	pub fn immortal() -> Self {
+		Era::Immortal
+	}
+
+	/// `true` if this is an immortal transaction.
+	pub fn is_immortal(&self) -> bool {
+		match self {
+			Era::Immortal => true,
+			_ => false,
+		}
+	}
+
+	/// Get the block number of the start of the era whose properties this object
+	/// describes that `current` belongs to. 
+	pub fn birth(self, current: u64) -> u64 {
+		match self {
+			Era::Immortal => 0,
+			Era::Mortal(period, phase) => (current - phase) / period * period + phase,
+		}
+	}
+
+	/// Get the block number of the first block at which the era has ended.
+	pub fn death(self, current: u64) -> u64 {
+		match self {
+			Era::Immortal => u64::max_value(),
+			Era::Mortal(period, _) => self.birth(current) + period,
+		}
+	}
+}
+
+impl Encode for Era {
+	fn encode_to<T: Output>(&self, output: &mut T) {
+		match self {
+			Era::Immortal => output.push_byte(0),
+			Era::Mortal(period, phase) => {
+				let quantize_factor = (*period as u64 >> 12).max(1);
+				let encoded = (period.trailing_zeros() - 1).max(1).min(15) as u16 | ((phase / quantize_factor) << 4) as u16;
+				output.push(&encoded);
+			}
+		}
+	}
+}
+
+impl Decode for Era {
+	fn decode<I: Input>(input: &mut I) -> Option<Self> {
+		let first = input.read_byte()?;
+		if first == 0 {
+			Some(Era::Immortal)
+		} else {
+			let encoded = first as u64 + ((input.read_byte()? as u64) << 8);
+			let period = 2 << (encoded % (1 << 4));
+			let quantize_factor = (period >> 12).max(1);
+			let phase = (encoded >> 4) * quantize_factor;
+			if period >= 4 && phase < period {
+				Some(Era::Mortal(period, phase))
+			} else {
+				None
+			}
+		}
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn immortal_works() {
+		let e = Era::immortal();
+		assert_eq!(e.birth(0), 0);
+		assert_eq!(e.death(0), u64::max_value());
+		assert_eq!(e.birth(1), 0);
+		assert_eq!(e.death(1), u64::max_value());
+		assert_eq!(e.birth(u64::max_value()), 0);
+		assert_eq!(e.death(u64::max_value()), u64::max_value());
+		assert!(e.is_immortal());
+
+		assert_eq!(e.encode(), vec![0u8]);
+		assert_eq!(e, Era::decode(&mut&[0u8][..]).unwrap());
+	}
+
+	#[test]
+	fn mortal_codec_works() {
+		let e = Era::mortal(64, 42);
+		assert!(!e.is_immortal());
+
+		let expected = vec![5 + 42 % 16 * 16, 42 / 16];
+		assert_eq!(e.encode(), expected);
+		assert_eq!(e, Era::decode(&mut&expected[..]).unwrap());
+	}
+
+	#[test]
+	fn long_period_mortal_codec_works() {
+		let e = Era::mortal(32768, 20000);
+
+		let expected = vec![(14 + 2500 % 16 * 16) as u8, (2500 / 16) as u8];
+		assert_eq!(e.encode(), expected);
+		assert_eq!(e, Era::decode(&mut&expected[..]).unwrap());
+	}
+
+	#[test]
+	fn era_initialisation_works() {
+		assert_eq!(Era::mortal(64, 42), Era::Mortal(64, 42));
+		assert_eq!(Era::mortal(32768, 20000), Era::Mortal(32768, 20000));
+		assert_eq!(Era::mortal(200, 513), Era::Mortal(256, 1));
+		assert_eq!(Era::mortal(2, 1), Era::Mortal(4, 1));
+		assert_eq!(Era::mortal(4, 5), Era::Mortal(4, 1));
+	}
+
+	#[test]
+	fn quantised_clamped_era_initialisation_works() {
+		// clamp 1000000 to 65536, quantise 1000001 % 65536 to the nearest 4
+		assert_eq!(Era::mortal(1000000, 1000001), Era::Mortal(65536, 1000001 % 65536 / 4 * 4));
+	}
+
+	#[test]
+	fn mortal_birth_death_works() {
+		let e = Era::mortal(4, 6);
+		for i in 6..10 {
+			assert_eq!(e.birth(i), 6);
+			assert_eq!(e.death(i), 10);
+		}
+
+		// wrong because it's outside of the (current...current + period) range
+		assert_ne!(e.birth(10), 6);
+		assert_ne!(e.birth(5), 6);
+	}
+}

substrate/core/sr-primitives/src/generic/mod.rs

@@ -19,6 +19,8 @@
 // end::description[]
 
 mod unchecked_extrinsic;
+mod unchecked_mortal_extrinsic;
+mod era;
 mod checked_extrinsic;
 mod header;
 mod block;
@@ -27,6 +29,8 @@ mod digest;
 mod tests;
 
 pub use self::unchecked_extrinsic::UncheckedExtrinsic;
+pub use self::unchecked_mortal_extrinsic::UncheckedMortalExtrinsic;
+pub use self::era::Era;
 pub use self::checked_extrinsic::CheckedExtrinsic;
 pub use self::header::Header;
 pub use self::block::{Block, SignedBlock, BlockId};

substrate/core/sr-primitives/src/generic/unchecked_extrinsic.rs

@@ -21,7 +21,7 @@ use std::fmt;
 
 use rstd::prelude::*;
 use codec::{Decode, Encode, Input};
-use traits::{self, Member, SimpleArithmetic, MaybeDisplay};
+use traits::{self, Member, SimpleArithmetic, MaybeDisplay, Lookup};
 use super::CheckedExtrinsic;
 
 /// A extrinsic right from the external world. This is unchecked and so
@@ -29,10 +29,9 @@ use super::CheckedExtrinsic;
 #[derive(PartialEq, Eq, Clone)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
 pub struct UncheckedExtrinsic<Address, Index, Call, Signature> {
-	/// The signature and address, if this is a signed extrinsic.
-	pub signature: Option<(Address, Signature)>,
-	/// The number of extrinsics have come before from the same signer.
-	pub index: Index,
+	/// The signature, address and number of extrinsics have come before from
+	/// the same signer, if this is a signed extrinsic.
+	pub signature: Option<(Address, Signature, Index)>,
 	/// The function that should be called.
 	pub function: Call,
 }
@@ -41,17 +40,15 @@ impl<Address, Index, Call, Signature> UncheckedExtrinsic<Address, Index, Call, S
 	/// New instance of a signed extrinsic aka "transaction".
 	pub fn new_signed(index: Index, function: Call, signed: Address, signature: Signature) -> Self {
 		UncheckedExtrinsic {
-			signature: Some((signed, signature)),
-			index,
+			signature: Some((signed, signature, index)),
 			function,
 		}
 	}
 
 	/// New instance of an unsigned extrinsic aka "inherent".
-	pub fn new_unsigned(index: Index, function: Call) -> Self {
+	pub fn new_unsigned(function: Call) -> Self {
 		UncheckedExtrinsic {
 			signature: None,
-			index,
 			function,
 		}
 	}
@@ -62,7 +59,7 @@ impl<Address, Index, Call, Signature> UncheckedExtrinsic<Address, Index, Call, S
 	}
 }
 
-impl<Address, AccountId, Index, Call, Signature, ThisLookup> traits::Checkable<ThisLookup>
+impl<Address, AccountId, Index, Call, Signature, Context> traits::Checkable<Context>
 	for UncheckedExtrinsic<Address, Index, Call, Signature>
 where
 	Address: Member + MaybeDisplay,
@@ -70,27 +67,25 @@ where
 	Call: Encode + Member,
 	Signature: Member + traits::Verify<Signer=AccountId>,
 	AccountId: Member + MaybeDisplay,
-	ThisLookup: FnOnce(Address) -> Result<AccountId, &'static str>,
+	Context: Lookup<Source=Address, Target=AccountId>,
 {
 	type Checked = CheckedExtrinsic<AccountId, Index, Call>;
 
-	fn check_with(self, lookup: ThisLookup) -> Result<Self::Checked, &'static str> {
+	fn check(self, context: &Context) -> Result<Self::Checked, &'static str> {
 		Ok(match self.signature {
-			Some((signed, signature)) => {
-				let payload = (self.index, self.function);
-				let signed = lookup(signed)?;
+			Some((signed, signature, index)) => {
+				let payload = (index, self.function);
+				let signed = context.lookup(signed)?;
 				if !::verify_encoded_lazy(&signature, &payload, &signed) {
 					return Err("bad signature in extrinsic")
 				}
 				CheckedExtrinsic {
-					signed: Some(signed),
-					index: payload.0,
+					signed: Some((signed, payload.0)),
 					function: payload.1,
 				}
 			}
 			None => CheckedExtrinsic {
 				signed: None,
-				index: self.index,
 				function: self.function,
 			},
 		})
@@ -114,7 +109,6 @@ where
 
 		Some(UncheckedExtrinsic {
 			signature: Decode::decode(input)?,
-			index: Decode::decode(input)?,
 			function: Decode::decode(input)?,
 		})
 	}
@@ -136,7 +130,6 @@ where
 		v.extend(&[0u8; 4]);
 
 		self.signature.encode_to(&mut v);
-		self.index.encode_to(&mut v);
 		self.function.encode_to(&mut v);
 
 		let length = (v.len() - 4) as u32;
@@ -154,6 +147,6 @@ impl<Address, Index, Call, Signature> fmt::Debug for UncheckedExtrinsic<Address,
 	Call: fmt::Debug,
 {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		write!(f, "UncheckedExtrinsic({:?}, {:?}, {:?})", self.signature.as_ref().map(|x| &x.0), self.function, self.index)
+		write!(f, "UncheckedExtrinsic({:?}, {:?})", self.signature.as_ref().map(|x| (&x.0, &x.2)), self.function)
 	}
 }

substrate/core/sr-primitives/src/generic/unchecked_mortal_extrinsic.rs

@@ -0,0 +1,278 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Generic implementation of an unchecked (pre-verification) extrinsic.
+
+#[cfg(feature = "std")]
+use std::fmt;
+
+use rstd::prelude::*;
+use codec::{Decode, Encode, Input};
+use traits::{self, Member, SimpleArithmetic, MaybeDisplay, GetHeight, BlockNumberToHash, Lookup,
+	Checkable};
+use super::{CheckedExtrinsic, Era};
+
+const TRANSACTION_VERSION: u8 = 1;
+
+/// A extrinsic right from the external world. This is unchecked and so
+/// can contain a signature.
+#[derive(PartialEq, Eq, Clone)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
+pub struct UncheckedMortalExtrinsic<Address, Index, Call, Signature> {
+	/// The signature, address, number of extrinsics have come before from
+	/// the same signer and an era describing the longevity of this transaction,
+	/// if this is a signed extrinsic.
+	pub signature: Option<(Address, Signature, Index, Era)>,
+	/// The function that should be called.
+	pub function: Call,
+}
+
+impl<Address, Index, Call, Signature> UncheckedMortalExtrinsic<Address, Index, Call, Signature> {
+	/// New instance of a signed extrinsic aka "transaction".
+	pub fn new_signed(index: Index, function: Call, signed: Address, signature: Signature, era: Era) -> Self {
+		UncheckedMortalExtrinsic {
+			signature: Some((signed, signature, index, era)),
+			function,
+		}
+	}
+
+	/// New instance of an unsigned extrinsic aka "inherent".
+	pub fn new_unsigned(function: Call) -> Self {
+		UncheckedMortalExtrinsic {
+			signature: None,
+			function,
+		}
+	}
+
+	/// `true` if there is a signature.
+	pub fn is_signed(&self) -> bool {
+		self.signature.is_some()
+	}
+}
+
+impl<Address, AccountId, Index, Call, Signature, Context, Hash, BlockNumber> Checkable<Context>
+	for UncheckedMortalExtrinsic<Address, Index, Call, Signature>
+where
+	Address: Member + MaybeDisplay,
+	Index: Encode + Member + MaybeDisplay + SimpleArithmetic,
+	Call: Encode + Member,
+	Signature: Member + traits::Verify<Signer=AccountId>,
+	AccountId: Member + MaybeDisplay,
+	BlockNumber: SimpleArithmetic,
+	Hash: Encode,
+	Context: Lookup<Source=Address, Target=AccountId>
+		+ GetHeight<BlockNumber=BlockNumber>
+		+ BlockNumberToHash<BlockNumber=BlockNumber, Hash=Hash>,
+{
+	type Checked = CheckedExtrinsic<AccountId, Index, Call>;
+
+	fn check(self, context: &Context) -> Result<Self::Checked, &'static str> {
+		Ok(match self.signature {
+			Some((signed, signature, index, era)) => {
+				let h = context.block_number_to_hash(BlockNumber::sa(era.birth(context.get_height().as_())))
+					.ok_or("transaction birth block ancient")?;
+				let payload = (index, self.function, h);
+				let signed = context.lookup(signed)?;
+				if !::verify_encoded_lazy(&signature, &payload, &signed) {
+					return Err("bad signature in extrinsic")
+				}
+				CheckedExtrinsic {
+					signed: Some((signed, payload.0)),
+					function: payload.1,
+				}
+			}
+			None => CheckedExtrinsic {
+				signed: None,
+				function: self.function,
+			},
+		})
+	}
+}
+
+impl<Address, Index, Call, Signature> Decode
+	for UncheckedMortalExtrinsic<Address, Index, Call, Signature>
+where
+	Address: Decode,
+	Signature: Decode,
+	Index: Decode,
+	Call: Decode,
+{
+	fn decode<I: Input>(input: &mut I) -> Option<Self> {
+		// This is a little more complicated than usual since the binary format must be compatible
+		// with substrate's generic `Vec<u8>` type. Basically this just means accepting that there
+		// will be a prefix of u32, which has the total number of bytes following (we don't need
+		// to use this).
+		let _length_do_not_remove_me_see_above: u32 = Decode::decode(input)?;
+
+		let version = input.read_byte()?;
+
+		let is_signed = version & 0b1000_0000 != 0;
+		let version = version & 0b0111_1111;
+		if version != TRANSACTION_VERSION {
+			return None
+		}
+
+		Some(UncheckedMortalExtrinsic {
+			signature: if is_signed { Some(Decode::decode(input)?) } else { None },
+			function: Decode::decode(input)?,
+		})
+	}
+}
+
+impl<Address, Index, Call, Signature> Encode
+	for UncheckedMortalExtrinsic<Address, Index, Call, Signature>
+where
+	Address: Encode,
+	Signature: Encode,
+	Index: Encode,
+	Call: Encode,
+{
+	fn encode(&self) -> Vec<u8> {
+		let mut v = Vec::new();
+
+		// need to prefix with the total length as u32 to ensure it's binary comptible with
+		// Vec<u8>. we'll make room for it here, then overwrite once we know the length.
+		v.extend(&[0u8; 4]);
+
+		// 1 byte version id.
+		match self.signature.as_ref() {
+			Some(s) => {
+				v.push(TRANSACTION_VERSION | 0b1000_0000);
+				s.encode_to(&mut v);
+			}
+			None => {
+				v.push(TRANSACTION_VERSION & 0b0111_1111);
+			}
+		}
+		self.function.encode_to(&mut v);
+
+		let length = (v.len() - 4) as u32;
+		length.using_encoded(|s| v[0..4].copy_from_slice(s));
+
+		v
+	}
+}
+
+/// TODO: use derive when possible.
+#[cfg(feature = "std")]
+impl<Address, Index, Call, Signature> fmt::Debug for UncheckedMortalExtrinsic<Address, Index, Call, Signature> where
+	Address: fmt::Debug,
+	Index: fmt::Debug,
+	Call: fmt::Debug,
+{
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		write!(f, "UncheckedMortalExtrinsic({:?}, {:?})", self.signature.as_ref().map(|x| (&x.0, &x.2)), self.function)
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	struct TestContext;
+	impl Lookup for TestContext {
+		type Source = u64;
+		type Target = u64;
+		fn lookup(&self, s: u64) -> Result<u64, &'static str> { Ok(s) }
+	}
+	impl GetHeight for TestContext {
+		type BlockNumber = u64;
+		fn get_height(&self) -> u64 { 42 }
+	}
+	impl BlockNumberToHash for TestContext {
+		type BlockNumber = u64;
+		type Hash = u64;
+		fn block_number_to_hash(&self, n: u64) -> Option<u64> { Some(n) }
+	}
+
+	#[derive(Eq, PartialEq, Clone, Debug, Serialize, Deserialize, Encode, Decode)]
+	struct TestSig(u64, Vec<u8>);
+	impl traits::Verify for TestSig {
+		type Signer = u64;
+		fn verify<L: traits::Lazy<[u8]>>(&self, mut msg: L, signer: &Self::Signer) -> bool {
+			*signer == self.0 && msg.get() == &self.1[..]
+		}
+	}
+
+	const DUMMY_FUNCTION: u64 = 0;
+	const DUMMY_ACCOUNTID: u64 = 0;
+	
+	type Ex = UncheckedMortalExtrinsic<u64, u64, u64, TestSig>;
+	type CEx = CheckedExtrinsic<u64, u64, u64>;
+
+	#[test]
+	fn unsigned_codec_should_work() {
+		let ux = Ex::new_unsigned(DUMMY_FUNCTION);
+		let encoded = ux.encode();
+		assert_eq!(Ex::decode(&mut &encoded[..]), Some(ux));
+	}
+
+	#[test]
+	fn signed_codec_should_work() {
+		let ux = Ex::new_signed(0, DUMMY_FUNCTION, DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, DUMMY_FUNCTION, 0u64).encode()), Era::immortal());
+		let encoded = ux.encode();
+		assert_eq!(Ex::decode(&mut &encoded[..]), Some(ux));
+	}
+
+	#[test]
+	fn unsigned_check_should_work() {
+		let ux = Ex::new_unsigned(DUMMY_FUNCTION);
+		assert!(!ux.is_signed());
+		assert!(<Ex as Checkable<TestContext>>::check(ux, &TestContext).is_ok());
+	}
+
+	#[test]
+	fn badly_signed_check_should_fail() {
+		let ux = Ex::new_signed(0, DUMMY_FUNCTION, DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, vec![0u8]), Era::immortal());
+		assert!(ux.is_signed());
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err("bad signature in extrinsic"));
+	}
+
+	#[test]
+	fn immortal_signed_check_should_work() {
+		let ux = Ex::new_signed(0, DUMMY_FUNCTION, DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, DUMMY_FUNCTION, 0u64).encode()), Era::immortal());
+		assert!(ux.is_signed());
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Ok(CEx { signed: Some((DUMMY_ACCOUNTID, 0)), function: DUMMY_FUNCTION }));
+	}
+
+	#[test]
+	fn mortal_signed_check_should_work() {
+		let ux = Ex::new_signed(0, DUMMY_FUNCTION, DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, DUMMY_FUNCTION, 42u64).encode()), Era::mortal(32, 42));
+		assert!(ux.is_signed());
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Ok(CEx { signed: Some((DUMMY_ACCOUNTID, 0)), function: DUMMY_FUNCTION }));
+	}
+
+	#[test]
+	fn later_mortal_signed_check_should_work() {
+		let ux = Ex::new_signed(0, DUMMY_FUNCTION, DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, DUMMY_FUNCTION, 11u64).encode()), Era::mortal(32, 11));
+		assert!(ux.is_signed());
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Ok(CEx { signed: Some((DUMMY_ACCOUNTID, 0)), function: DUMMY_FUNCTION }));
+	}
+
+	#[test]
+	fn too_late_mortal_signed_check_should_fail() {
+		let ux = Ex::new_signed(0, DUMMY_FUNCTION, DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, DUMMY_FUNCTION, 10u64).encode()), Era::mortal(32, 10));
+		assert!(ux.is_signed());
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err("bad signature in extrinsic"));
+	}
+
+	#[test]
+	fn too_early_mortal_signed_check_should_fail() {
+		let ux = Ex::new_signed(0, DUMMY_FUNCTION, DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, DUMMY_FUNCTION, 43u64).encode()), Era::mortal(32, 43));
+		assert!(ux.is_signed());
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err("bad signature in extrinsic"));
+	}
+}