Deterministic IDGraph sorting (#2310)

* Deterministic IDGraph sorting

* consider multiple identities within block

* avoid using rand for tests

---------

Co-authored-by: Kai <7630809+Kailai-Wang@users.noreply.github.com>

Author: Igor Trofimov

tee-worker/litentry/pallets/identity-management/src/lib.rs

@@ -36,6 +36,7 @@ pub mod migrations;
 
 pub use pallet::*;
 pub mod identity_context;
+use core::cmp::Ordering;
 pub use identity_context::*;
 
 use frame_support::{pallet_prelude::*, sp_runtime::traits::One, traits::StorageVersion};
@@ -294,7 +295,18 @@ pub mod pallet {
 		// get the whole IDGraph, sorted by `link_block` (earliest -> latest)
 		pub fn get_id_graph(who: &Identity) -> IDGraph<T> {
 			let mut id_graph = IDGraphs::iter_prefix(who).collect::<IDGraph<T>>();
-			id_graph.sort_by(|a, b| Ord::cmp(&a.1.link_block, &b.1.link_block));
+
+			// Initial sort to ensure a deterministic order
+			id_graph.sort_by(|a, b| {
+				let order = Ord::cmp(&a.1.link_block, &b.1.link_block);
+				if order == Ordering::Equal {
+					// Compare identities by their did formated string
+					Ord::cmp(&a.0.to_did().ok(), &b.0.to_did().ok())
+				} else {
+					order
+				}
+			});
+
 			id_graph
 		}
 

tee-worker/litentry/pallets/identity-management/src/tests.rs

@@ -17,7 +17,6 @@
 use crate::{mock::*, Error, IDGraph, Identity, IdentityContext, IdentityStatus, Web3Network};
 use frame_support::{assert_err, assert_noop, assert_ok, traits::Get};
 use sp_runtime::AccountId32;
-
 pub const ALICE: AccountId32 = AccountId32::new([1u8; 32]);
 pub const BOB: AccountId32 = AccountId32::new([2u8; 32]);
 pub const CHARLIE: AccountId32 = AccountId32::new([3u8; 32]);
@@ -422,14 +421,76 @@ fn get_id_graph_works() {
 		let id_graph = IMT::get_id_graph(&who);
 		assert_eq!(id_graph.len(), 22);
 
-		// index 0 has the oldest identity
 		assert_eq!(id_graph.get(0).unwrap().0, who);
 
 		// index 21 has the newest identity
 		assert_eq!(id_graph.get(21).unwrap().0, alice_twitter_identity(21));
 	});
 }
 
+#[test]
+fn get_id_graph_identities_within_same_block() {
+	new_test_ext().execute_with(|| {
+		let who: Identity = ALICE.into();
+		System::set_block_number(1);
+
+		let identities = vec![
+			(alice_twitter_identity(1), vec![]),
+			(alice_substrate_identity(), vec![Web3Network::LitentryRococo]),
+			(alice_evm_identity(), vec![Web3Network::Ethereum]),
+			(bob_substrate_identity(), vec![Web3Network::Litentry]),
+		];
+
+		for (identity, networks) in identities {
+			assert_ok!(IMT::link_identity(
+				RuntimeOrigin::signed(ALICE),
+				who.clone(),
+				identity,
+				networks,
+			));
+		}
+
+		let id_graph = IMT::get_id_graph(&who);
+		let sorted_identities = [
+			alice_evm_identity(),
+			who.clone(),
+			bob_substrate_identity(),
+			alice_substrate_identity(),
+			alice_twitter_identity(1),
+		];
+
+		for (i, identity) in sorted_identities.iter().enumerate() {
+			assert_eq!(&id_graph.get(i).unwrap().0, identity);
+		}
+
+		// clear all identites
+		assert_ok!(IMT::remove_identity(RuntimeOrigin::signed(ALICE), who.clone(), vec![],));
+
+		// change order of the identites
+		let identities = vec![
+			(bob_substrate_identity(), vec![Web3Network::Litentry]),
+			(alice_substrate_identity(), vec![Web3Network::LitentryRococo]),
+			(alice_twitter_identity(1), vec![]),
+			(alice_evm_identity(), vec![Web3Network::Ethereum]),
+		];
+
+		for (identity, networks) in identities {
+			assert_ok!(IMT::link_identity(
+				RuntimeOrigin::signed(ALICE),
+				who.clone(),
+				identity,
+				networks,
+			));
+		}
+
+		let id_graph = IMT::get_id_graph(&who);
+
+		for (i, identity) in sorted_identities.iter().enumerate() {
+			assert_eq!(&id_graph.get(i).unwrap().0, identity);
+		}
+	});
+}
+
 #[test]
 fn id_graph_stats_works() {
 	new_test_ext().execute_with(|| {