test: Add end-to-end test

Author: armsnyder

.gitignore

@@ -0,0 +1 @@
+/tmp/

e2e_test.go

@@ -0,0 +1,74 @@
+package main_test
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"testing"
+	"time"
+
+	. "github.com/onsi/gomega"
+
+	"github.com/samber/lo"
+)
+
+func TestE2E(t *testing.T) {
+	g := NewWithT(t)
+
+	// Build the server binary
+	binPath := filepath.Join(t.TempDir(), "gdshader-language-server")
+	g.Expect(exec.Command("go", "build", "-cover", "-o", binPath, ".").Run()).To(Succeed(), "Failed to build server")
+
+	// Configure the server command
+	const coverDir = "tmp/cover/e2e"
+	lo.Must0(os.MkdirAll(coverDir, 0o700))
+	var stdout bytes.Buffer
+	cmd := exec.Command(binPath, "-debug")
+	cmd.Env = []string{"GOCOVERDIR=" + coverDir}
+	cmd.Stderr = os.Stderr
+	cmd.Stdout = &stdout
+	stdin := lo.Must(cmd.StdinPipe())
+
+	// Start the server
+	g.Expect(cmd.Start()).To(Succeed(), "Failed to start server")
+	t.Cleanup(func() { _ = cmd.Process.Kill() })
+
+	// Send JSON-RPC requests to the server
+
+	send := func(s string) {
+		var buf bytes.Buffer
+		buf.WriteString("Content-Length: ")
+		buf.WriteString(strconv.Itoa(len(s)))
+		buf.WriteString("\r\n\r\n")
+		buf.WriteString(s)
+		lo.Must(io.Copy(stdin, &buf))
+	}
+
+	send(`{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}`)
+	send(`{"jsonrpc":"2.0","id":2,"method":"shutdown"}`)
+	send(`{"jsonrpc":"2.0","method":"exit"}`)
+
+	// Wait for the server to exit
+	select {
+	case err := <-lo.Async(cmd.Wait):
+		g.Expect(err).ToNot(HaveOccurred(), "Server exited with error")
+	case <-time.After(5 * time.Second):
+		t.Fatal("Server did not exit in time")
+	}
+
+	// Check the output
+
+	var expected string
+
+	expect := func(s string) {
+		expected += "Content-Length: " + strconv.Itoa(len(s)) + "\r\nContent-Type: application/vscode-jsonrpc; charset=utf-8\r\n\r\n" + s
+	}
+
+	expect(`{"jsonrpc":"2.0","id":1,"result":{"capabilities":{"textDocumentSync":{"openClose":true,"change":1}},"serverInfo":{"name":"gdshader-language-server","version":"development"}}}`)
+	expect(`{"jsonrpc":"2.0","id":2,"result":null}`)
+
+	g.Expect(stdout.String()).To(BeComparableTo(string(expected)), "Output does not match expected")
+}

internal/handler/handler.go

@@ -11,7 +11,7 @@ type Handler struct {
 	isUTF8 bool
 }
 
-func (h *Handler) Initialize(clientCapabilities *lsp.ClientCapabilities) (*lsp.ServerCapabilities, error) {
+func (h *Handler) Initialize(clientCapabilities lsp.ClientCapabilities) (*lsp.ServerCapabilities, error) {
 	var serverCapabilities lsp.ServerCapabilities
 	serverCapabilities.TextDocumentSync.OpenClose = true
 

internal/lsp/server.go

@@ -14,7 +14,7 @@ import (
 )
 
 type Handler interface {
-	Initialize(clientCapabilities *ClientCapabilities) (*ServerCapabilities, error)
+	Initialize(clientCapabilities ClientCapabilities) (*ServerCapabilities, error)
 }
 
 type Server struct {
@@ -49,7 +49,7 @@ func (s *Server) Serve() error {
 
 		if len(request.ID) == 0 {
 			logger := slog.With("method", request.Method)
-			logger.Debug("Received notification")
+			logger.Debug("Received notification", "params", string(request.Params))
 
 			if request.Method == "exit" {
 				logger.Info("Exiting")
@@ -64,7 +64,7 @@ func (s *Server) Serve() error {
 		}
 
 		logger := slog.With("request_id", request.ID, "method", request.Method)
-		logger.Debug("Received request")
+		logger.Debug("Received request", "params", string(request.Params))
 
 		response, err := s.handleRequest(request.Method, request.Params)
 		if err != nil {
@@ -142,7 +142,7 @@ func (s *Server) handleRequest(method string, paramsRaw json.RawMessage) (any, e
 				Name    string `json:"name"`
 				Version string `json:"version"`
 			} `json:"clientInfo"`
-			Capabilities *ClientCapabilities `json:"capabilities"`
+			Capabilities ClientCapabilities `json:"capabilities"`
 		}
 		if err := parseParams(paramsRaw, &params); err != nil {
 			return nil, err

main.go

@@ -29,7 +29,7 @@ func main() {
 
 	server := &lsp.Server{
 		Info: lsp.ServerInfo{
-			Name:    "gdshader-lsp",
+			Name:    "gdshader-language-server",
 			Version: Version,
 		},
 		Handler: &handler.Handler{},