Fix solver competition loading for multiple winners (#3049)

# Description
A breaking change of SolverCompetitionAPI, which now potentially returns
more than 1 transaction associated with the competition (will notify all
teams on slack soon).

Resolves one of the points from
#2830 (comment)

# Changes
<!-- List of detailed changes (how the change is accomplished) -->

- [ ] SolverCompetitionAPI now returns `Vec<TransactionHash>`, instead
of `Option<TransactionHash>`

## How to test
Refactored unit test to prove it works and that no regression issues
were introduced.
Existing e2e test for solver competition proves that competition is
properly returned.

crates/autopilot/src/database/competition.rs

@@ -149,7 +149,7 @@ impl super::Postgres {
                 deserialize_solver_competition(
                     row.json,
                     row.id,
-                    row.tx_hash.map(|hash| H256(hash.0)),
+                    row.tx_hashes.iter().map(|hash| H256(hash.0)).collect(),
                 )
             })
             .transpose()
@@ -159,13 +159,13 @@ impl super::Postgres {
 fn deserialize_solver_competition(
     json: JsonValue,
     auction_id: model::auction::AuctionId,
-    transaction_hash: Option<H256>,
+    transaction_hashes: Vec<H256>,
 ) -> anyhow::Result<SolverCompetitionAPI> {
     let common: SolverCompetitionDB =
         serde_json::from_value(json).context("deserialize SolverCompetitionDB")?;
     Ok(SolverCompetitionAPI {
         auction_id,
-        transaction_hash,
+        transaction_hashes,
         common,
     })
 }

crates/database/src/solver_competition.rs

@@ -20,19 +20,21 @@ VALUES ($1, $2)
 pub struct LoadCompetition {
     pub json: JsonValue,
     pub id: AuctionId,
-    pub tx_hash: Option<TransactionHash>,
+    // Multiple settlements can be associated with a single competition.
+    pub tx_hashes: Vec<TransactionHash>,
 }
 
 pub async fn load_by_id(
     ex: &mut PgConnection,
     id: AuctionId,
 ) -> Result<Option<LoadCompetition>, sqlx::Error> {
     const QUERY: &str = r#"
-SELECT sc.json, sc.id, s.tx_hash
+SELECT sc.json, sc.id, COALESCE(ARRAY_AGG(s.tx_hash) FILTER (WHERE s.tx_hash IS NOT NULL), '{}') AS tx_hashes
 FROM solver_competitions sc
 -- outer joins because the data might not have been indexed yet
 LEFT OUTER JOIN settlements s ON sc.id = s.auction_id
 WHERE sc.id = $1
+GROUP BY sc.id
     ;"#;
     sqlx::query_as(QUERY).bind(id).fetch_optional(ex).await
 }
@@ -41,10 +43,11 @@ pub async fn load_latest_competition(
     ex: &mut PgConnection,
 ) -> Result<Option<LoadCompetition>, sqlx::Error> {
     const QUERY: &str = r#"
-SELECT sc.json, sc.id, s.tx_hash
+SELECT sc.json, sc.id, COALESCE(ARRAY_AGG(s.tx_hash) FILTER (WHERE s.tx_hash IS NOT NULL), '{}') AS tx_hashes
 FROM solver_competitions sc
 -- outer joins because the data might not have been indexed yet
 LEFT OUTER JOIN settlements s ON sc.id = s.auction_id
+GROUP BY sc.id
 ORDER BY sc.id DESC
 LIMIT 1
     ;"#;
@@ -56,10 +59,17 @@ pub async fn load_by_tx_hash(
     tx_hash: &TransactionHash,
 ) -> Result<Option<LoadCompetition>, sqlx::Error> {
     const QUERY: &str = r#"
-SELECT sc.json, sc.id, s.tx_hash
+WITH competition AS (
+    SELECT sc.id
+    FROM solver_competitions sc
+    JOIN settlements s ON sc.id = s.auction_id
+    WHERE s.tx_hash = $1
+)
+SELECT sc.json, sc.id, COALESCE(ARRAY_AGG(s.tx_hash) FILTER (WHERE s.tx_hash IS NOT NULL), '{}') AS tx_hashes
 FROM solver_competitions sc
 JOIN settlements s ON sc.id = s.auction_id
-WHERE s.tx_hash = $1
+WHERE sc.id = (SELECT id FROM competition)
+GROUP BY sc.id
     ;"#;
     sqlx::query_as(QUERY).bind(tx_hash).fetch_optional(ex).await
 }
@@ -70,7 +80,7 @@ mod tests {
         super::*,
         crate::{
             byte_array::ByteArray,
-            events::{Event, EventIndex, Settlement},
+            events::{EventIndex, Settlement},
         },
         sqlx::Connection,
     };
@@ -84,61 +94,76 @@ mod tests {
 
         let value = JsonValue::Bool(true);
         save(&mut db, 0, &value).await.unwrap();
+
+        // load by id works
         let value_ = load_by_id(&mut db, 0).await.unwrap().unwrap();
         assert_eq!(value, value_.json);
-        assert!(value_.tx_hash.is_none());
+        assert!(value_.tx_hashes.is_empty());
+        // load as latest works
+        let value_ = load_latest_competition(&mut db).await.unwrap().unwrap();
+        assert_eq!(value, value_.json);
+        assert!(value_.tx_hashes.is_empty());
+        // load by tx doesn't work, as there is no settlement yet
+        assert!(load_by_tx_hash(&mut db, &ByteArray([0u8; 32]))
+            .await
+            .unwrap()
+            .is_none());
 
+        // non-existent auction returns none
         assert!(load_by_id(&mut db, 1).await.unwrap().is_none());
-    }
-
-    #[tokio::test]
-    #[ignore]
-    async fn postgres_by_hash() {
-        let mut db = PgConnection::connect("postgresql://").await.unwrap();
-        let mut db = db.begin().await.unwrap();
-        crate::clear_DANGER_(&mut db).await.unwrap();
-
-        let id: i64 = 5;
-        let value = JsonValue::Bool(true);
-        let hash = ByteArray([1u8; 32]);
-        save(&mut db, id, &value).await.unwrap();
-
-        let value_by_id = load_by_id(&mut db, id).await.unwrap().unwrap();
-        assert_eq!(value, value_by_id.json);
-        // no hash because hash columns isn't used to find it
-        assert!(value_by_id.tx_hash.is_none());
-
-        // Fails because the tx_hash stored directly in the solver_competitions table is
-        // no longer used to look the competition up.
-        assert!(load_by_tx_hash(&mut db, &hash).await.unwrap().is_none());
-
-        // Now insert the proper settlement event and account-nonce.
-
-        let index = EventIndex::default();
-        let event = Event::Settlement(Settlement {
-            solver: Default::default(),
-            transaction_hash: hash,
-        });
-        crate::events::append(&mut db, &[(index, event)])
-            .await
-            .unwrap();
 
-        crate::settlements::update_settlement_auction(
+        // insert two settlement events for the same auction id
+        crate::events::insert_settlement(
+            &mut db,
+            &EventIndex {
+                block_number: 0,
+                log_index: 0,
+            },
+            &Settlement {
+                solver: Default::default(),
+                transaction_hash: ByteArray([0u8; 32]),
+            },
+        )
+        .await
+        .unwrap();
+        crate::events::insert_settlement(
             &mut db,
-            index.block_number,
-            index.log_index,
-            id,
+            &EventIndex {
+                block_number: 0,
+                log_index: 1,
+            },
+            &Settlement {
+                solver: Default::default(),
+                transaction_hash: ByteArray([1u8; 32]),
+            },
         )
         .await
         .unwrap();
+        crate::settlements::update_settlement_auction(&mut db, 0, 0, 0)
+            .await
+            .unwrap();
+        crate::settlements::update_settlement_auction(&mut db, 0, 1, 0)
+            .await
+            .unwrap();
+
+        // load by id works, and finds two hashes
+        let value_ = load_by_id(&mut db, 0).await.unwrap().unwrap();
+        assert!(value_.tx_hashes.len() == 2);
 
-        // Now succeeds.
-        let value_by_hash = load_by_tx_hash(&mut db, &hash).await.unwrap().unwrap();
-        assert_eq!(value, value_by_hash.json);
-        assert_eq!(id, value_by_hash.id);
+        // load as latest works, and finds two hashes
+        let value_ = load_latest_competition(&mut db).await.unwrap().unwrap();
+        assert!(value_.tx_hashes.len() == 2);
 
-        // By id also sees the hash now.
-        let value_by_id = load_by_id(&mut db, id).await.unwrap().unwrap();
-        assert_eq!(hash, value_by_id.tx_hash.unwrap());
+        // load by tx works, and finds two hashes, no matter which tx hash is used
+        let value_ = load_by_tx_hash(&mut db, &ByteArray([0u8; 32]))
+            .await
+            .unwrap()
+            .unwrap();
+        assert!(value_.tx_hashes.len() == 2);
+        let value_ = load_by_tx_hash(&mut db, &ByteArray([1u8; 32]))
+            .await
+            .unwrap()
+            .unwrap();
+        assert!(value_.tx_hashes.len() == 2);
     }
 }

crates/model/src/solver_competition.rs

@@ -25,7 +25,7 @@ pub struct SolverCompetitionDB {
 pub struct SolverCompetitionAPI {
     #[serde(default)]
     pub auction_id: AuctionId,
-    pub transaction_hash: Option<H256>,
+    pub transaction_hashes: Vec<H256>,
     #[serde(flatten)]
     pub common: SolverCompetitionDB,
 }
@@ -126,7 +126,7 @@ mod tests {
             "auctionId": 0,
             "auctionStartBlock": 13u64,
             "competitionSimulationBlock": 15u64,
-            "transactionHash": "0x1111111111111111111111111111111111111111111111111111111111111111",
+            "transactionHashes": ["0x1111111111111111111111111111111111111111111111111111111111111111"],
             "auction": {
                 "orders": [
                     "0x1111111111111111111111111111111111111111111111111111111111111111\
@@ -173,7 +173,7 @@ mod tests {
 
         let orig = SolverCompetitionAPI {
             auction_id: 0,
-            transaction_hash: Some(H256([0x11; 32])),
+            transaction_hashes: vec![H256([0x11; 32])],
             common: SolverCompetitionDB {
                 auction_start_block: 13,
                 competition_simulation_block: 15,
@@ -360,7 +360,7 @@ mod tests {
               }
             }
           ],
-          "transactionHash": "0x044499c2a830890cb0a8ecf9aec6c5621e8310092a58d369cdef726254d3d108",
+          "transactionHashes": ["0x044499c2a830890cb0a8ecf9aec6c5621e8310092a58d369cdef726254d3d108"],
           "auctionStartBlock": 15173535,
           "liquidityCollectedBlock": 15173535,
           "competitionSimulationBlock": 15173535

crates/orderbook/src/database/solver_competition.rs

@@ -14,13 +14,13 @@ use {
 fn deserialize_solver_competition(
     json: JsonValue,
     auction_id: AuctionId,
-    transaction_hash: Option<H256>,
+    transaction_hashes: Vec<H256>,
 ) -> Result<SolverCompetitionAPI, LoadSolverCompetitionError> {
     let common: SolverCompetitionDB =
         serde_json::from_value(json).context("deserialize SolverCompetitionDB")?;
     Ok(SolverCompetitionAPI {
         auction_id,
-        transaction_hash,
+        transaction_hashes,
         common,
     })
 }
@@ -45,14 +45,20 @@ impl SolverCompetitionStoring for Postgres {
                     deserialize_solver_competition(
                         row.json,
                         row.id,
-                        row.tx_hash.map(|hash| H256(hash.0)),
+                        row.tx_hashes.iter().map(|hash| H256(hash.0)).collect(),
                     )
                 }),
             Identifier::Transaction(hash) => {
                 database::solver_competition::load_by_tx_hash(&mut ex, &ByteArray(hash.0))
                     .await
                     .context("solver_competition::load_by_tx_hash")?
-                    .map(|row| deserialize_solver_competition(row.json, row.id, Some(hash)))
+                    .map(|row| {
+                        deserialize_solver_competition(
+                            row.json,
+                            row.id,
+                            row.tx_hashes.iter().map(|hash| H256(hash.0)).collect(),
+                        )
+                    })
             }
         }
         .ok_or(LoadSolverCompetitionError::NotFound)?
@@ -74,7 +80,7 @@ impl SolverCompetitionStoring for Postgres {
                 deserialize_solver_competition(
                     row.json,
                     row.id,
-                    row.tx_hash.map(|hash| H256(hash.0)),
+                    row.tx_hashes.iter().map(|hash| H256(hash.0)).collect(),
                 )
             })
             .ok_or(LoadSolverCompetitionError::NotFound)?