test(e2e): solve_grid over real MCP stdio with fake LLM

test/e2e/server_test.go

@@ -0,0 +1,78 @@
+//go:build e2e
+
+package e2e
+
+import (
+	"context"
+	"encoding/json"
+	"os/exec"
+	"testing"
+	"time"
+
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+)
+
+func TestSolveGridOverStdio(t *testing.T) {
+	llmSrv := startFakeLLM()
+	defer llmSrv.Close()
+
+	cmd := exec.Command("../../bin/captcha-solver-mcp")
+	cmd.Env = append(cmd.Environ(),
+		"CAPTCHA_LLM_PROVIDER=openai-compatible",
+		"CAPTCHA_LLM_BASE_URL="+llmSrv.URL,
+		"CAPTCHA_LLM_API_KEY=test",
+		"CAPTCHA_LLM_MODEL=fake",
+	)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	client := mcp.NewClient(&mcp.Implementation{Name: "e2e", Version: "v0"}, nil)
+	session, err := client.Connect(ctx, &mcp.CommandTransport{Command: cmd}, nil)
+	if err != nil {
+		t.Fatalf("connect: %v", err)
+	}
+	defer func() { _ = session.Close() }()
+
+	res, err := session.CallTool(ctx, &mcp.CallToolParams{
+		Name: "solve_grid_captcha",
+		Arguments: map[string]any{
+			"screenshot":   "iVBORw0KGgo=",
+			"instruction":  "select all buses",
+			"rows":         3,
+			"cols":         3,
+			"image_width":  300,
+			"image_height": 300,
+		},
+	})
+	if err != nil {
+		t.Fatalf("call: %v", err)
+	}
+	assertTiles(t, res, []int{0, 1, 2})
+}
+
+// assertTiles unmarshals the structured tool result and compares tiles.
+func assertTiles(t *testing.T, res *mcp.CallToolResult, want []int) {
+	t.Helper()
+	if res.IsError {
+		t.Fatalf("tool returned error: %+v", res.Content)
+	}
+	raw, err := json.Marshal(res.StructuredContent)
+	if err != nil {
+		t.Fatalf("marshal structured: %v", err)
+	}
+	var out struct {
+		Tiles []int `json:"tiles"`
+	}
+	if err := json.Unmarshal(raw, &out); err != nil {
+		t.Fatalf("unmarshal %q: %v", raw, err)
+	}
+	if len(out.Tiles) != len(want) {
+		t.Fatalf("tiles=%v want %v", out.Tiles, want)
+	}
+	for i := range want {
+		if out.Tiles[i] != want[i] {
+			t.Fatalf("tiles=%v want %v", out.Tiles, want)
+		}
+	}
+}