refactor(baseapp): improve readability of preblock (#21179)

Author: facundomedica

baseapp/abci.go

@@ -786,10 +786,11 @@ func (app *BaseApp) internalFinalizeBlock(ctx context.Context, req *abci.Finaliz
 			WithHeaderHash(req.Hash))
 	}
 
-	if err := app.preBlock(req); err != nil {
+	preblockEvents, err := app.preBlock(req)
+	if err != nil {
 		return nil, err
 	}
-	events = append(events, app.finalizeBlockState.ctx.EventManager().ABCIEvents()...)
+	events = append(events, preblockEvents...)
 
 	beginBlock, err := app.beginBlock(req)
 	if err != nil {

baseapp/baseapp.go

@@ -709,11 +709,12 @@ func (app *BaseApp) cacheTxContext(ctx sdk.Context, txBytes []byte) (sdk.Context
 	return ctx.WithMultiStore(msCache), msCache
 }
 
-func (app *BaseApp) preBlock(req *abci.FinalizeBlockRequest) error {
+func (app *BaseApp) preBlock(req *abci.FinalizeBlockRequest) ([]abci.Event, error) {
+	var events []abci.Event
 	if app.preBlocker != nil {
 		ctx := app.finalizeBlockState.Context()
 		if err := app.preBlocker(ctx, req); err != nil {
-			return err
+			return nil, err
 		}
 		// ConsensusParams can change in preblocker, so we need to
 		// write the consensus parameters in store to context
@@ -722,8 +723,9 @@ func (app *BaseApp) preBlock(req *abci.FinalizeBlockRequest) error {
 		gasMeter := app.getBlockGasMeter(ctx)
 		ctx = ctx.WithBlockGasMeter(gasMeter)
 		app.finalizeBlockState.SetContext(ctx)
+		events = ctx.EventManager().ABCIEvents()
 	}
-	return nil
+	return events, nil
 }
 
 func (app *BaseApp) beginBlock(_ *abci.FinalizeBlockRequest) (sdk.BeginBlock, error) {