fix: invalid state with posting A -> A (#1138)

components/ledger/internal/engine/resolver.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"sync"
 
+	"github.com/pkg/errors"
+
 	"github.com/formancehq/ledger/internal/storage/ledgerstore"
 
 	"github.com/ThreeDotsLabs/watermill/message"
@@ -79,6 +81,9 @@ func (r *Resolver) startLedgerUsingStore(ctx context.Context, name string, store
 }
 
 func (r *Resolver) GetLedger(ctx context.Context, name string) (*Ledger, error) {
+	if name == "" {
+		return nil, errors.New("empty name")
+	}
 	r.lock.RLock()
 	ledger, ok := r.ledgers[name]
 	r.lock.RUnlock()

components/ledger/internal/storage/ledgerstore/bucket.go

@@ -17,6 +17,9 @@ import (
 //go:embed migrations/0-init-schema.sql
 var initSchema string
 
+//go:embed migrations/1-fix-trigger.sql
+var fixTrigger string
+
 type Bucket struct {
 	name string
 	db   *bun.DB
@@ -127,6 +130,13 @@ func registerMigrations(migrator *migrations.Migrator, name string) {
 				return nil
 			},
 		},
+		migrations.Migration{
+			Name: "Fix trigger",
+			UpWithContext: func(ctx context.Context, tx bun.Tx) error {
+				_, err := tx.ExecContext(ctx, fixTrigger)
+				return err
+			},
+		},
 	)
 }
 

components/ledger/internal/storage/ledgerstore/migrations/1-fix-trigger.sql

@@ -0,0 +1,31 @@
+create or replace function insert_posting(_transaction_seq bigint, _ledger varchar, _insertion_date timestamp without time zone,
+                               _effective_date timestamp without time zone, posting jsonb, _account_metadata jsonb)
+    returns void
+    language plpgsql
+as
+$$
+declare
+    _source_exists      bool;
+    _destination_exists bool;
+begin
+
+    select true from accounts where ledger = _ledger and address = posting ->> 'source' into _source_exists;
+    if posting ->>'source' = posting->>'destination' then
+        _destination_exists = true;
+    else
+        select true from accounts where ledger = _ledger and address = posting ->> 'destination' into _destination_exists;
+    end if;
+
+    perform upsert_account(_ledger, posting ->> 'source', _account_metadata -> (posting ->> 'source'), _insertion_date);
+    perform upsert_account(_ledger, posting ->> 'destination', _account_metadata -> (posting ->> 'destination'),
+                           _insertion_date);
+
+    -- todo: sometimes the balance is known at commit time (for sources != world), we need to forward the value to populate the pre_commit_aggregated_input and output
+    perform insert_move(_transaction_seq, _ledger, _insertion_date, _effective_date,
+                        posting ->> 'source', posting ->> 'asset', (posting ->> 'amount')::numeric, true,
+                        _source_exists);
+    perform insert_move(_transaction_seq, _ledger, _insertion_date, _effective_date,
+                        posting ->> 'destination', posting ->> 'asset', (posting ->> 'amount')::numeric, false,
+                        _destination_exists);
+end;
+$$;

components/ledger/internal/storage/ledgerstore/transactions_test.go

@@ -1074,3 +1074,20 @@ func TestGetLastTransaction(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, *tx3, tx.Transaction)
 }
+
+func TestTransactionFromWorldToWorld(t *testing.T) {
+	t.Parallel()
+	store := newLedgerStore(t)
+	ctx := logging.TestingContext()
+
+	tx := ledger.NewTransaction().
+		WithIDUint64(0).
+		WithPostings(
+			ledger.NewPosting("world", "world", "USD", big.NewInt(100)),
+		)
+	require.NoError(t, store.InsertLogs(ctx, ledger.ChainLogs(ledger.NewTransactionLog(tx, map[string]metadata.Metadata{}))...))
+
+	account, err := store.GetAccountWithVolumes(ctx, NewGetAccountQuery("world").WithExpandVolumes())
+	require.NoError(t, err)
+	internaltesting.RequireEqual(t, big.NewInt(0), account.Volumes.Balances()["USD"])
+}