feat(acp/handlers): fs/read_text_file + fs/write_text_file with path safety

internal/acp/handlers/server_fs_read_test.go

@@ -0,0 +1,89 @@
+package handlers_test
+
+import (
+	"context"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/yan1h/agent-coding-workflow/internal/acp/handlers"
+)
+
+func TestFsRead_HappyPath(t *testing.T) {
+	t.Parallel()
+	tmp := t.TempDir()
+	require.NoError(t, os.WriteFile(filepath.Join(tmp, "a.txt"), []byte("hello\n"), 0o644))
+
+	h := handlers.NewFsReadHandler()
+	sess := handlers.SessionContext{SessionID: uuid.New(), CwdPath: tmp}
+	params := mustJSON(t, map[string]any{"sessionId": "x", "path": filepath.Join(tmp, "a.txt")})
+
+	res := h.Handle(context.Background(), sess, params)
+	require.Nil(t, res.Err)
+	require.NotNil(t, res.OK)
+	var out struct {
+		Content string `json:"content"`
+	}
+	require.NoError(t, json.Unmarshal(res.OK, &out))
+	assert.Equal(t, "hello\n", out.Content)
+}
+
+func TestFsRead_PathOutsideWorktree(t *testing.T) {
+	t.Parallel()
+	tmp := t.TempDir()
+	h := handlers.NewFsReadHandler()
+	sess := handlers.SessionContext{CwdPath: tmp}
+	outside := filepath.Join(filepath.VolumeName(tmp)+string(filepath.Separator), "etc", "passwd")
+	params := mustJSON(t, map[string]any{"sessionId": "x", "path": outside})
+
+	res := h.Handle(context.Background(), sess, params)
+	require.NotNil(t, res.Err)
+	assert.Equal(t, -32001, res.Err.Code)
+}
+
+func TestFsRead_FileNotFound(t *testing.T) {
+	t.Parallel()
+	tmp := t.TempDir()
+	h := handlers.NewFsReadHandler()
+	sess := handlers.SessionContext{CwdPath: tmp}
+	params := mustJSON(t, map[string]any{"sessionId": "x", "path": filepath.Join(tmp, "nope.txt")})
+
+	res := h.Handle(context.Background(), sess, params)
+	require.NotNil(t, res.Err)
+	assert.Equal(t, -32603, res.Err.Code)
+}
+
+func TestFsRead_LineLimit(t *testing.T) {
+	t.Parallel()
+	tmp := t.TempDir()
+	require.NoError(t, os.WriteFile(filepath.Join(tmp, "f.txt"),
+		[]byte("L0\nL1\nL2\nL3\n"), 0o644))
+
+	h := handlers.NewFsReadHandler()
+	sess := handlers.SessionContext{CwdPath: tmp}
+	line := 1
+	limit := 2
+	params := mustJSON(t, map[string]any{
+		"sessionId": "x", "path": filepath.Join(tmp, "f.txt"),
+		"line": line, "limit": limit,
+	})
+	res := h.Handle(context.Background(), sess, params)
+	require.Nil(t, res.Err)
+	var out struct {
+		Content string `json:"content"`
+	}
+	_ = json.Unmarshal(res.OK, &out)
+	assert.Equal(t, "L1\nL2", out.Content)
+}
+
+func mustJSON(t *testing.T, v any) json.RawMessage {
+	t.Helper()
+	b, err := json.Marshal(v)
+	require.NoError(t, err)
+	return b
+}