Offchain Phragmén BREAKING. (#4517)

* Initial skeleton for offchain phragmen

* Basic compact encoding decoding for results

* add compact files

* Bring back Self::ensure_storage_upgraded();

* Make staking use compact stuff.

* First seemingly working version of reduce, full of todos

* Everything phragmen related works again.

* Signing made easier, still issues.

* Signing from offchain compile fine 😎

* make compact work with staked asssignment

* Evaluation basics are in place.

* Move reduce into crate. Document stuff

* move reduce into no_std

* Add files

* Remove other std deps. Runtime compiles

* Seemingly it is al stable; cycle implemented but not integrated.

* Add fuzzing code.

* Cleanup reduce a bit more.

* a metric ton of tests for staking; wip 🔨

* Implement a lot more of the tests.

* wip getting the unsigned stuff to work

* A bit gleanup for unsigned debug

* Clean and finalize compact code.

* Document reduce.

* Still problems with signing

* We officaly duct taped the transaction submission stuff. 🤓

* Deadlock with keys again

* Runtime builds

* Unsigned test works 🙌

* Some cleanups

* Make all the tests compile and stuff

* Minor cleanup

* fix more merge stuff

* Most tests work again.

* a very nasty bug in reduce

* Fix all integrations

* Fix more todos

* Revamp everything and everything

* Remove bogus test

* Some review grumbles.

* Some fixes

* Fix doc test

* loop for submission

* Fix cli, keyring etc.

* some cleanup

* Fix staking tests again

* fix per-things; bring patches from benchmarking

* better score prediction

* Add fuzzer, more patches.

* Some fixes

* More docs

* Remove unused generics

* Remove max-nominator footgun

* Better fuzzer

* Disable it ❌

* Bump.

* Another round of self-review

* Refactor a lot

* More major fixes in perThing

* Add new fuzz file

* Update lock

* fix fuzzing code.

* Fix nominator retain test

* Add slashing check

* Update frame/staking/src/tests.rs

Co-Authored-By: Joshy Orndorff <JoshOrndorff@users.noreply.github.com>

* Some formatting nits

* Review comments.

* Fix cargo file

* Almost all tests work again

* Update frame/staking/src/tests.rs

Co-Authored-By: thiolliere <gui.thiolliere@gmail.com>

* Fix review comments

* More review stuff

* Some nits

* Fix new staking / session / babe relation

* Update primitives/phragmen/src/lib.rs

Co-Authored-By: thiolliere <gui.thiolliere@gmail.com>

* Update primitives/phragmen/src/lib.rs

Co-Authored-By: thiolliere <gui.thiolliere@gmail.com>

* Update primitives/phragmen/compact/src/lib.rs

Co-Authored-By: thiolliere <gui.thiolliere@gmail.com>

* Some doc updates to slashing

* Fix derive

* Remove imports

* Remove unimplemented tests

* nits

* Remove dbg

* Better fuzzing params

* Remove unused pref map

* Deferred Slashing/Offence for offchain Phragmen  (#5151)

* Some boilerplate

* Add test

* One more test

* Review comments

* Fix build

* review comments

* fix more

* fix build

* Some cleanups and self-reviews

* More minor self reviews

* Final nits

* Some merge fixes.

* opt comment

* Fix build

* Fix build again.

* Update frame/staking/fuzz/fuzz_targets/submit_solution.rs

Co-Authored-By: Gavin Wood <gavin@parity.io>

* Update frame/staking/src/slashing.rs

Co-Authored-By: Gavin Wood <gavin@parity.io>

* Update frame/staking/src/offchain_election.rs

Co-Authored-By: Gavin Wood <gavin@parity.io>

* Fix review comments

* fix test

* === 🔑 Revamp without staking key.

* final round of changes.

* Fix cargo-deny

* Update frame/staking/src/lib.rs

Co-Authored-By: Gavin Wood <gavin@parity.io>

Co-authored-by: Joshy Orndorff <JoshOrndorff@users.noreply.github.com>
Co-authored-by: thiolliere <gui.thiolliere@gmail.com>
Co-authored-by: Gavin Wood <gavin@parity.io>

substrate/frame/babe/src/tests.rs

@@ -17,11 +17,10 @@
 //! Consensus extension module tests for BABE consensus.
 
 use super::*;
+use mock::*;
 use frame_support::traits::OnFinalize;
-use mock::{new_test_ext, Babe, System};
-use sp_runtime::testing::{Digest, DigestItem};
-use sp_consensus_vrf::schnorrkel::{RawVRFOutput, RawVRFProof};
 use pallet_session::ShouldEndSession;
+use sp_consensus_vrf::schnorrkel::{RawVRFOutput, RawVRFProof};
 
 const EMPTY_RANDOMNESS: [u8; 32] = [
 	74, 25, 49, 128, 53, 97, 244, 49,
@@ -30,24 +29,6 @@ const EMPTY_RANDOMNESS: [u8; 32] = [
 	217, 153, 138, 37, 48, 192, 248, 0,
 ];
 
-fn make_pre_digest(
-	authority_index: sp_consensus_babe::AuthorityIndex,
-	slot_number: sp_consensus_babe::SlotNumber,
-	vrf_output: RawVRFOutput,
-	vrf_proof: RawVRFProof,
-) -> Digest {
-	let digest_data = sp_consensus_babe::digests::RawPreDigest::Primary(
-		sp_consensus_babe::digests::RawPrimaryPreDigest {
-			authority_index,
-			slot_number,
-			vrf_output,
-			vrf_proof,
-		}
-	);
-	let log = DigestItem::PreRuntime(sp_consensus_babe::BABE_ENGINE_ID, digest_data.encode());
-	Digest { logs: vec![log] }
-}
-
 #[test]
 fn empty_randomness_is_correct() {
 	let s = compute_randomness([0; RANDOMNESS_LENGTH], 0, std::iter::empty(), None);
@@ -132,3 +113,24 @@ fn authority_index() {
 			"Trivially invalid authorities are ignored")
 	})
 }
+
+#[test]
+fn can_predict_next_epoch_change() {
+	new_test_ext(vec![]).execute_with(|| {
+		assert_eq!(<Test as Trait>::EpochDuration::get(), 3);
+		// this sets the genesis slot to 6;
+		go_to_block(1, 6);
+		assert_eq!(Babe::genesis_slot(), 6);
+		assert_eq!(Babe::current_slot(), 6);
+		assert_eq!(Babe::epoch_index(), 0);
+
+		progress_to_block(5);
+
+		assert_eq!(Babe::epoch_index(), 5 / 3);
+		assert_eq!(Babe::current_slot(), 10);
+
+		// next epoch change will be at
+		assert_eq!(Babe::current_epoch_start(), 9); // next change will be 12, 2 slots from now
+		assert_eq!(Babe::next_expected_epoch_change(System::block_number()), Some(5 + 2));
+	})
+}