Improve readability in handleQueryP2P (cosmos#9205)

* refactor(abci handleP2PQuery): improve readability via control flow

* refactor(acbi handleQueryP2P): fix logic control flow to ensure early return

* refactor(abci handleQueryP2P): move var declaration to prevent unnecessary initialization

* support(CHANGELOG): add description for abci handleQueryP2P changes

Co-authored-by: Marko <marbar3778@yahoo.com>
Co-authored-by: Amaury <1293565+amaurym@users.noreply.github.com>

CHANGELOG.md

@@ -35,6 +35,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 # Changelog
 
 ## [Unreleased]
+* [\#9205](https://github.com/cosmos/cosmos-sdk/pull/9205) Improve readability in `abci` handleQueryP2P
 
 ## Features
 * [\#8965](https://github.com/cosmos/cosmos-sdk/pull/8965) cosmos reflection now provides more information on the application such as: deliverable msgs, sdk.Config info etc (still in alpha stage).

baseapp/abci.go

@@ -799,28 +799,32 @@ func handleQueryStore(app *BaseApp, path []string, req abci.RequestQuery) abci.R
 
 func handleQueryP2P(app *BaseApp, path []string) abci.ResponseQuery {
 	// "/p2p" prefix for p2p queries
-	if len(path) >= 4 {
-		cmd, typ, arg := path[1], path[2], path[3]
-		switch cmd {
-		case "filter":
-			switch typ {
-			case "addr":
-				return app.FilterPeerByAddrPort(arg)
-
-			case "id":
-				return app.FilterPeerByID(arg)
-			}
+	if len(path) < 4 {
+		return sdkerrors.QueryResult(
+			sdkerrors.Wrap(
+				sdkerrors.ErrUnknownRequest, "path should be p2p filter <addr|id> <parameter>",
+			),
+		)
+	}
 
-		default:
-			return sdkerrors.QueryResult(sdkerrors.Wrap(sdkerrors.ErrUnknownRequest, "expected second parameter to be 'filter'"))
+	var resp abci.ResponseQuery
+
+	cmd, typ, arg := path[1], path[2], path[3]
+	switch cmd {
+	case "filter":
+		switch typ {
+		case "addr":
+			resp = app.FilterPeerByAddrPort(arg)
+
+		case "id":
+			resp = app.FilterPeerByID(arg)
 		}
+
+	default:
+		resp = sdkerrors.QueryResult(sdkerrors.Wrap(sdkerrors.ErrUnknownRequest, "expected second parameter to be 'filter'"))
 	}
 
-	return sdkerrors.QueryResult(
-		sdkerrors.Wrap(
-			sdkerrors.ErrUnknownRequest, "expected path is p2p filter <addr|id> <parameter>",
-		),
-	)
+	return resp
 }
 
 func handleQueryCustom(app *BaseApp, path []string, req abci.RequestQuery) abci.ResponseQuery {