inproc_rpc_test.go

package rrpc

import (
	"fmt"
	"net"
	"strings"
	"testing"
)

// TestInProcRPC tests using in-memory pipe as connection
func TestInProcJsonRPC(t *testing.T) {
	newServer := NewServer()
	newServer.Register(new(Arith))
	newServer.Register(new(Embed))
	newServer.RegisterName("net.rpc.Arith", new(Arith))
	newServer.RegisterName("newServer.Arith", new(Arith))

	// change default codec to JSON
	NewDefaultCodec = NewJsonCodec

	cliConn, srvConn := net.Pipe()
	defer cliConn.Close()

	go newServer.ServeConn(srvConn)

	client := NewClient(cliConn)

	// Synchronous calls
	args := &Args{7, 8}
	reply := new(Reply)
	err := client.Call("Arith.Add", args, reply)
	if err != nil {
		t.Errorf("Add: expected no error but got string %q", err.Error())
	}
	if reply.C != args.A+args.B {
		t.Errorf("Add: expected %d got %d", reply.C, args.A+args.B)
	}

	// Methods exported from unexported embedded structs
	args = &Args{7, 0}
	reply = new(Reply)
	err = client.Call("Embed.Exported", args, reply)
	if err != nil {
		t.Errorf("Add: expected no error but got string %q", err.Error())
	}
	if reply.C != args.A+args.B {
		t.Errorf("Add: expected %d got %d", reply.C, args.A+args.B)
	}

	// Nonexistent method
	args = &Args{7, 0}
	reply = new(Reply)
	err = client.Call("Arith.BadOperation", args, reply)
	// expect an error
	if err == nil {
		t.Error("BadOperation: expected error")
	} else if !strings.HasPrefix(err.Error(), "rpc: can't find method ") {
		t.Errorf("BadOperation: expected can't find method error; got %q", err)
	}

	// Unknown service
	args = &Args{7, 8}
	reply = new(Reply)
	err = client.Call("Arith.Unknown", args, reply)
	if err == nil {
		t.Error("expected error calling unknown service")
	} else if !strings.Contains(err.Error(), "method") {
		t.Error("expected error about method; got", err)
	}

	// Out of order.
	args = &Args{7, 8}
	mulReply := new(Reply)
	mulCall := client.Go("Arith.Mul", args, mulReply, nil)
	addReply := new(Reply)
	addCall := client.Go("Arith.Add", args, addReply, nil)

	addCall = <-addCall.Done
	if addCall.Error != nil {
		t.Errorf("Add: expected no error but got string %q", addCall.Error.Error())
	}
	if addReply.C != args.A+args.B {
		t.Errorf("Add: expected %d got %d", addReply.C, args.A+args.B)
	}

	mulCall = <-mulCall.Done
	if mulCall.Error != nil {
		t.Errorf("Mul: expected no error but got string %q", mulCall.Error.Error())
	}
	if mulReply.C != args.A*args.B {
		t.Errorf("Mul: expected %d got %d", mulReply.C, args.A*args.B)
	}

	// Error test
	args = &Args{7, 0}
	reply = new(Reply)
	err = client.Call("Arith.Div", args, reply)
	// expect an error: zero divide
	if err == nil {
		t.Error("Div: expected error")
	} else if err.Error() != "divide by zero" {
		t.Error("Div: expected divide by zero error; got", err)
	}

	// Bad type.
	reply = new(Reply)
	err = client.Call("Arith.Add", reply, reply) // args, reply would be the correct thing to use
	if err == nil {
		t.Error("expected error calling Arith.Add with wrong arg type")
	} else if !strings.Contains(err.Error(), "unknown") {
		t.Error("expected error about unknown; got", err)
	}

	// Non-struct argument
	const Val = 12345
	str := fmt.Sprint(Val)
	reply = new(Reply)
	err = client.Call("Arith.Scan", &str, reply)
	if err != nil {
		t.Errorf("Scan: expected no error but got string %q", err.Error())
	} else if reply.C != Val {
		t.Errorf("Scan: expected %d got %d", Val, reply.C)
	}

	// Non-struct reply
	args = &Args{27, 35}
	str = ""
	err = client.Call("Arith.String", args, &str)
	if err != nil {
		t.Errorf("String: expected no error but got string %q", err.Error())
	}
	expect := fmt.Sprintf("%d+%d=%d", args.A, args.B, args.A+args.B)
	if str != expect {
		t.Errorf("String: expected %s got %s", expect, str)
	}

	args = &Args{7, 8}
	reply = new(Reply)
	err = client.Call("Arith.Mul", args, reply)
	if err != nil {
		t.Errorf("Mul: expected no error but got string %q", err.Error())
	}
	if reply.C != args.A*args.B {
		t.Errorf("Mul: expected %d got %d", reply.C, args.A*args.B)
	}

	// ServiceName contain "." character
	args = &Args{7, 8}
	reply = new(Reply)
	err = client.Call("net.rpc.Arith.Add", args, reply)
	if err != nil {
		t.Errorf("Add: expected no error but got string %q", err.Error())
	}
	if reply.C != args.A+args.B {
		t.Errorf("Add: expected %d got %d", reply.C, args.A+args.B)
	}
}