jsonrpc - client_test.go

  package jsonrpc
  
  import (
  	"bytes"
  	"encoding/json"
  	"errors"
  	"io"
  	"reflect"
  	"testing"
  	"time"
  )
  
  type rw struct {
  	io.ReadCloser
  	io.WriteCloser
  }
  
  func (r *rw) Close() error {
  	r.ReadCloser.Close()
  	r.WriteCloser.Close()
  
  	return nil
  }
  
  func makeServerClientConn() (ReadWriteCloser, ReadWriteCloser) {
  	ar, bw := io.Pipe()
  	br, aw := io.Pipe()
  
  	return &rw{
  			ReadCloser:  ar,
  			WriteCloser: aw,
  		}, &rw{
  			ReadCloser:  br,
  			WriteCloser: bw,
  		}
  }
  
  type simpleHandler struct{}
  
  var ErrUnknownEndpoint = &Error{
  	Message: "unknown endpoint",
  }
  
  func (simpleHandler) HandleRPC(method string, data json.RawMessage) (any, error) {
  	switch method {
  	case "add":
  		var toAdd [2]int
  		if err := json.Unmarshal(data, &toAdd); err != nil {
  			return nil, err
  		}
  
  		return toAdd[0] + toAdd[1], nil
  	}
  	return nil, ErrUnknownEndpoint
  }
  
  func TestRequest(t *testing.T) {
  	serverConn, clientConn := makeServerClientConn()
  
  	s := New(serverConn, new(simpleHandler))
  	go s.Handle()
  	defer serverConn.Close()
  
  	c := NewClient(clientConn)
  	defer c.Close()
  
  	for n, test := range [...]struct {
  		Method   string
  		Params   any
  		Response json.RawMessage
  		Error    error
  	}{
  		{
  			Method: "unknown",
  			Error:  ErrUnknownEndpoint,
  		},
  		{
  			Method:   "add",
  			Params:   [2]int{5, 6},
  			Response: json.RawMessage{'1', '1'},
  		},
  	} {
  		resp, err := c.Request(test.Method, test.Params)
  		if !errors.Is(test.Error, err) {
  			t.Errorf("test %d: expecting error %s, got %s", n+1, test.Error, err)
  		} else if !bytes.Equal(test.Response, resp) {
  			t.Errorf("test %d: expecting response %s, got %s", n+1, test.Response, resp)
  		}
  	}
  }
  
  func TestAwait(t *testing.T) {
  	t.Parallel()
  	serverConn, clientConn := makeServerClientConn()
  
  	s := New(serverConn, new(simpleHandler))
  	go s.Handle()
  	defer serverConn.Close()
  
  	c := NewClient(clientConn)
  	defer c.Close()
  
  	resp := make(chan int, 2)
  
  	c.Await(-1, func(data json.RawMessage) {
  		var num int
  		json.Unmarshal(data, &num)
  
  		resp <- num
  	})
  
  	total := receiveData(s, resp)
  	if total != 5 {
  		t.Errorf("expecting result 5, got %d", total)
  	}
  }
  
  func receiveData(s *Server, ch chan int) int {
  	s.Send(Response{
  		ID:     -1,
  		Result: 5,
  	})
  	s.Send(Response{
  		ID:     -1,
  		Result: 6,
  	})
  
  	var total int
  	timeout := time.After(time.Second)
  
  Loop:
  	for {
  		select {
  		case num := <-ch:
  			total += num
  		case <-timeout:
  			break Loop
  		}
  	}
  
  	return total
  }
  
  func TestSubscribe(t *testing.T) {
  	t.Parallel()
  	serverConn, clientConn := makeServerClientConn()
  
  	s := New(serverConn, new(simpleHandler))
  	go s.Handle()
  	defer serverConn.Close()
  
  	c := NewClient(clientConn)
  	defer c.Close()
  
  	resp := make(chan int, 2)
  
  	c.Subscribe(-1, func(data json.RawMessage) {
  		var num int
  		json.Unmarshal(data, &num)
  
  		resp <- num
  	})
  
  	total := receiveData(s, resp)
  
  	if total != 11 {
  		t.Errorf("expecting result 11, got %d", total)
  	}
  }
  
  func TestRequestValue(t *testing.T) {
  	serverConn, clientConn := makeServerClientConn()
  
  	s := New(serverConn, new(simpleHandler))
  	go s.Handle()
  	defer serverConn.Close()
  
  	c := NewClient(clientConn)
  	defer c.Close()
  
  	for n, test := range [...]struct {
  		Method   string
  		Params   any
  		Response any
  		Error    error
  	}{
  		{
  			Method:   "add",
  			Params:   [2]int{5, 6},
  			Response: int(11),
  		},
  	} {
  		v := reflect.New(reflect.TypeOf(test.Response))
  		err := c.RequestValue(test.Method, test.Params, v.Interface())
  		if !errors.Is(test.Error, err) {
  			t.Errorf("test %d: expecting error %s, got %s", n+1, test.Error, err)
  		} else if resp := v.Elem().Interface(); !reflect.DeepEqual(test.Response, resp) {
  			t.Errorf("test %d: expecting response %s, got %s", n+1, test.Response, resp)
  		}
  	}
  }