rpc: clean up the RPCFunc constructor signature (#7586)

Instead of taking a comma-separated string of parameter names, take each
parameter name as a separate argument. Now that we no longer have an extra flag
for caching, this fits nicely into a variadic trailer.

* Update all usage of NewRPCFunc and NewWSRPCFunc.

rpc/jsonrpc/doc.go

@@ -55,7 +55,7 @@
 // Define some routes
 //
 //   var Routes = map[string]*rpcserver.RPCFunc{
-//	    "status": rpcserver.NewRPCFunc(Status, "arg", false),
+//	    "status": rpcserver.NewRPCFunc(Status, "arg"),
 //   }
 //
 // An rpc function:

rpc/jsonrpc/server/http_json_handler_test.go

@@ -18,7 +18,7 @@ import (
 
 func testMux() *http.ServeMux {
 	funcMap := map[string]*RPCFunc{
-		"c":     NewRPCFunc(func(ctx context.Context, s string, i int) (string, error) { return "foo", nil }, "s,i"),
+		"c":     NewRPCFunc(func(ctx context.Context, s string, i int) (string, error) { return "foo", nil }, "s", "i"),
 		"block": NewRPCFunc(func(ctx context.Context, h int) (string, error) { return "block", nil }, "height"),
 	}
 	mux := http.NewServeMux()

rpc/jsonrpc/server/parse_test.go

@@ -135,7 +135,7 @@ func TestParseJSONArray(t *testing.T) {
 
 func TestParseJSONRPC(t *testing.T) {
 	demo := func(ctx context.Context, height int, name string) {}
-	call := NewRPCFunc(demo, "height,name")
+	call := NewRPCFunc(demo, "height", "name")
 
 	cases := []struct {
 		raw    string
@@ -172,7 +172,7 @@ func TestParseJSONRPC(t *testing.T) {
 
 func TestParseURI(t *testing.T) {
 	demo := func(ctx context.Context, height int, name string) {}
-	call := NewRPCFunc(demo, "height,name")
+	call := NewRPCFunc(demo, "height", "name")
 
 	cases := []struct {
 		raw    []string

rpc/jsonrpc/server/rpc_func.go

@@ -3,7 +3,6 @@ package server
 import (
 	"net/http"
 	"reflect"
-	"strings"
 
 	"github.com/tendermint/tendermint/libs/log"
 )
@@ -35,26 +34,22 @@ type RPCFunc struct {
 
 // NewRPCFunc wraps a function for introspection.
 // f is the function, args are comma separated argument names
-func NewRPCFunc(f interface{}, args string) *RPCFunc {
-	return newRPCFunc(f, args, false)
+func NewRPCFunc(f interface{}, argNames ...string) *RPCFunc {
+	return newRPCFunc(f, argNames, false)
 }
 
 // NewWSRPCFunc wraps a function for introspection and use in the websockets.
-func NewWSRPCFunc(f interface{}, args string) *RPCFunc {
-	return newRPCFunc(f, args, true)
+func NewWSRPCFunc(f interface{}, argNames ...string) *RPCFunc {
+	return newRPCFunc(f, argNames, true)
 }
 
-func newRPCFunc(f interface{}, args string, ws bool) *RPCFunc {
-	var argNames []string
-	if args != "" {
-		argNames = strings.Split(args, ",")
-	}
+func newRPCFunc(f interface{}, argNames []string, wsOnly bool) *RPCFunc {
 	return &RPCFunc{
 		f:        reflect.ValueOf(f),
 		args:     funcArgTypes(f),
 		returns:  funcReturnTypes(f),
 		argNames: argNames,
-		ws:       ws,
+		ws:       wsOnly,
 	}
 }
 

rpc/jsonrpc/server/ws_handler_test.go

@@ -47,7 +47,7 @@ func TestWebsocketManagerHandler(t *testing.T) {
 
 func newWSServer(t *testing.T, logger log.Logger) *httptest.Server {
 	funcMap := map[string]*RPCFunc{
-		"c": NewWSRPCFunc(func(ctx context.Context, s string, i int) (string, error) { return "foo", nil }, "s,i"),
+		"c": NewWSRPCFunc(func(ctx context.Context, s string, i int) (string, error) { return "foo", nil }, "s", "i"),
 	}
 	wm := NewWebsocketManager(logger, funcMap)
 

rpc/jsonrpc/test/main.go

@@ -13,7 +13,7 @@ import (
 )
 
 var routes = map[string]*rpcserver.RPCFunc{
-	"hello_world": rpcserver.NewRPCFunc(HelloWorld, "name,num"),
+	"hello_world": rpcserver.NewRPCFunc(HelloWorld, "name", "num"),
 }
 
 func HelloWorld(ctx context.Context, name string, num int) (Result, error) {