fix(libreoffice): render scrolled workbooks in full for SinglePageSheets

pkg/modules/libreoffice/api/singlepagesheets_test.go

@@ -0,0 +1,216 @@
+package api
+
+import (
+	"archive/zip"
+	"bytes"
+	"context"
+	"io"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// buildWorkbook packs entries into an in-memory xlsx-like zip.
+func buildWorkbook(t *testing.T, entries map[string]string) []byte {
+	t.Helper()
+	var buf bytes.Buffer
+	w := zip.NewWriter(&buf)
+	for name, content := range entries {
+		f, err := w.Create(name)
+		if err != nil {
+			t.Fatalf("create entry %q: %v", name, err)
+		}
+		_, err = f.Write([]byte(content))
+		if err != nil {
+			t.Fatalf("write entry %q: %v", name, err)
+		}
+	}
+	err := w.Close()
+	if err != nil {
+		t.Fatalf("close workbook: %v", err)
+	}
+	return buf.Bytes()
+}
+
+func readEntry(t *testing.T, workbook []byte, name string) string {
+	t.Helper()
+	r, err := zip.NewReader(bytes.NewReader(workbook), int64(len(workbook)))
+	if err != nil {
+		t.Fatalf("open workbook: %v", err)
+	}
+	for _, f := range r.File {
+		if f.Name != name {
+			continue
+		}
+		rc, err := f.Open()
+		if err != nil {
+			t.Fatalf("open entry %q: %v", name, err)
+		}
+		defer rc.Close()
+		data, err := io.ReadAll(rc)
+		if err != nil {
+			t.Fatalf("read entry %q: %v", name, err)
+		}
+		return string(data)
+	}
+	t.Fatalf("entry %q not found", name)
+	return ""
+}
+
+const scrolledSheet = `<?xml version="1.0"?><worksheet><dimension ref="A1:B83"/>` +
+	`<sheetViews><sheetView tabSelected="1" topLeftCell="A37" workbookViewId="0">` +
+	`<pane topLeftCell="A37"/><selection activeCell="A1" sqref="A1"/></sheetView></sheetViews>` +
+	`<sheetData><row r="1"><c r="A1"><v>1</v></c></row></sheetData></worksheet>`
+
+const topSheet = `<?xml version="1.0"?><worksheet><dimension ref="A1:B83"/>` +
+	`<sheetViews><sheetView tabSelected="1" workbookViewId="0"/></sheetViews>` +
+	`<sheetData><row r="1"><c r="A1"><v>1</v></c></row></sheetData></worksheet>`
+
+func TestStripWorksheetScrollPosition(t *testing.T) {
+	for _, tc := range []struct {
+		scenario     string
+		workbook     []byte
+		expectErr    bool
+		expectChange bool
+	}{
+		{
+			scenario: "removes topLeftCell from sheetView and pane",
+			workbook: buildWorkbook(t, map[string]string{
+				"[Content_Types].xml":      "<Types/>",
+				"xl/worksheets/sheet1.xml": scrolledSheet,
+				"xl/sharedStrings.xml":     "<sst/>",
+			}),
+			expectChange: true,
+		},
+		{
+			scenario: "leaves a workbook without a saved scroll position untouched",
+			workbook: buildWorkbook(t, map[string]string{
+				"[Content_Types].xml":      "<Types/>",
+				"xl/worksheets/sheet1.xml": topSheet,
+			}),
+			expectChange: false,
+		},
+		{
+			scenario: "only rewrites worksheet entries",
+			workbook: buildWorkbook(t, map[string]string{
+				"xl/worksheets/sheet1.xml": scrolledSheet,
+				// A stray topLeftCell elsewhere must not be touched.
+				"xl/workbook.xml": `<workbook topLeftCell="A9"/>`,
+			}),
+			expectChange: true,
+		},
+		{
+			scenario:  "rejects a non-zip input",
+			workbook:  []byte("not a zip file"),
+			expectErr: true,
+		},
+	} {
+		t.Run(tc.scenario, func(t *testing.T) {
+			out, changed, err := stripWorksheetScrollPosition(tc.workbook)
+
+			if tc.expectErr {
+				if err == nil {
+					t.Fatalf("expected error, got nil")
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if changed != tc.expectChange {
+				t.Fatalf("expected changed=%v, got %v", tc.expectChange, changed)
+			}
+			if !changed {
+				return
+			}
+
+			// The rewrite must round-trip and hold the same entries.
+			if err = validateWorkbook(tc.workbook, out); err != nil {
+				t.Fatalf("rewritten workbook did not validate: %v", err)
+			}
+			if strings.Contains(readEntry(t, out, "xl/worksheets/sheet1.xml"), "topLeftCell") {
+				t.Fatalf("worksheet still contains topLeftCell")
+			}
+			// Non-worksheet entries are copied verbatim.
+			if _, ok := entryNames(t, out)["xl/workbook.xml"]; ok {
+				if got := readEntry(t, out, "xl/workbook.xml"); got != `<workbook topLeftCell="A9"/>` {
+					t.Fatalf("non-worksheet entry was modified: %q", got)
+				}
+			}
+		})
+	}
+}
+
+func entryNames(t *testing.T, workbook []byte) map[string]struct{} {
+	t.Helper()
+	r, err := zip.NewReader(bytes.NewReader(workbook), int64(len(workbook)))
+	if err != nil {
+		t.Fatalf("open workbook: %v", err)
+	}
+	names := make(map[string]struct{}, len(r.File))
+	for _, f := range r.File {
+		names[f.Name] = struct{}{}
+	}
+	return names
+}
+
+func TestResetCalcScrollPosition(t *testing.T) {
+	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
+	ctx := context.Background()
+
+	writeFile := func(t *testing.T, name string, content []byte) string {
+		t.Helper()
+		path := filepath.Join(t.TempDir(), name)
+		err := os.WriteFile(path, content, 0o600)
+		if err != nil {
+			t.Fatalf("write %q: %v", name, err)
+		}
+		return path
+	}
+
+	t.Run("non-xlsx input is returned unchanged", func(t *testing.T) {
+		path := writeFile(t, "input.docx", []byte("whatever"))
+		if got := resetCalcScrollPosition(ctx, logger, path); got != path {
+			t.Fatalf("expected %q, got %q", path, got)
+		}
+	})
+
+	t.Run("workbook without a scroll position is returned unchanged", func(t *testing.T) {
+		path := writeFile(t, "input.xlsx", buildWorkbook(t, map[string]string{
+			"xl/worksheets/sheet1.xml": topSheet,
+		}))
+		if got := resetCalcScrollPosition(ctx, logger, path); got != path {
+			t.Fatalf("expected original path %q, got %q", path, got)
+		}
+	})
+
+	t.Run("corrupt xlsx falls back to the original path", func(t *testing.T) {
+		path := writeFile(t, "input.xlsx", []byte("PK\x03\x04 not really a zip"))
+		if got := resetCalcScrollPosition(ctx, logger, path); got != path {
+			t.Fatalf("expected fallback to %q, got %q", path, got)
+		}
+	})
+
+	t.Run("scrolled workbook yields a sanitized copy", func(t *testing.T) {
+		path := writeFile(t, "input.xlsx", buildWorkbook(t, map[string]string{
+			"[Content_Types].xml":      "<Types/>",
+			"xl/worksheets/sheet1.xml": scrolledSheet,
+		}))
+		got := resetCalcScrollPosition(ctx, logger, path)
+		if got == path {
+			t.Fatalf("expected a sanitized copy, got the original path")
+		}
+		if filepath.Dir(got) != filepath.Dir(path) {
+			t.Fatalf("sanitized copy escaped the working directory: %q", got)
+		}
+		sanitized, err := os.ReadFile(got)
+		if err != nil {
+			t.Fatalf("read sanitized file: %v", err)
+		}
+		if strings.Contains(readEntry(t, sanitized, "xl/worksheets/sheet1.xml"), "topLeftCell") {
+			t.Fatalf("sanitized worksheet still contains topLeftCell")
+		}
+	})
+}