Improve the export pipeline (shared ordering + chapter page breaks)

- buildDocx/buildOdt now accept an explicit ordered chapter list, making that
  list the single source of truth for export ordering (defaults to whole book)
- Emit real page breaks between chapters in DOCX, with none before the first
- Unify the DOCX/ODT handlers into one exportOffice pipeline (ODT still built
  from the same DOCX via LibreOffice)

src/main/index.ts

@@ -382,59 +382,43 @@ ipcMain.handle("folio:exportPdf", async () => {
   }
 });
 
-// Export the manuscript as a DOCX. Built entirely in the main process from the
-// chapter files, so it does not depend on which view is on screen. The e2e
-// harness overrides the save dialog with FOLIO_TEST_DOCX.
-ipcMain.handle("folio:exportDocx", async () => {
+// Export the manuscript as a DOCX or ODT. Both formats share one pipeline: the
+// native chapter documents are assembled in canonical order (see buildDocx), and
+// ODT is produced from that same DOCX via LibreOffice so the two stay consistent.
+// The e2e harness overrides the save dialog with FOLIO_TEST_DOCX / FOLIO_TEST_ODT.
+async function exportOffice(format: "docx" | "odt") {
   try {
     const bp = requireBook();
+    const ext = format;
+    const envKey = format === "docx" ? "FOLIO_TEST_DOCX" : "FOLIO_TEST_ODT";
     let filePath: string;
-    if (process.env.FOLIO_SELF_TEST === "1" && process.env.FOLIO_TEST_DOCX) {
-      filePath = process.env.FOLIO_TEST_DOCX;
+    if (process.env.FOLIO_SELF_TEST === "1" && process.env[envKey]) {
+      filePath = process.env[envKey] as string;
     } else {
       const { canceled, filePath: chosen } = await showSaveDialog({
-        title: "Export Full Book as DOCX",
-        defaultPath: `${currentBookTitle()}.docx`,
-        filters: [{ name: "Word Document", extensions: ["docx"] }],
+        title: `Export Full Book as ${format.toUpperCase()}`,
+        defaultPath: `${currentBookTitle()}.${ext}`,
+        filters: [
+          {
+            name: format === "docx" ? "Word Document" : "OpenDocument Text",
+            extensions: [ext],
+          },
+        ],
       });
       if (canceled || !chosen) return { canceled: true } as const;
-      filePath = chosen.endsWith(".docx") ? chosen : `${chosen}.docx`;
+      filePath = chosen.endsWith(`.${ext}`) ? chosen : `${chosen}.${ext}`;
     }
-    const buf = await buildDocx(bp);
+    const buf = format === "docx" ? await buildDocx(bp) : await buildOdt(bp);
     fs.writeFileSync(filePath, buf);
-    const docxOk = buf.length > 0 && buf.subarray(0, 2).toString("utf-8") === "PK";
-    return { ok: true, filePath, bytes: buf.length, docxOk };
+    const ok = buf.length > 0 && buf.subarray(0, 2).toString("utf-8") === "PK";
+    return { ok: true, filePath, bytes: buf.length, [`${format}Ok`]: ok };
   } catch (e) {
     return { error: (e as Error).message };
   }
-});
+}
 
-// Export the manuscript as an ODT via LibreOffice (converted from the same
-// DOCX so both exports stay consistent). Fails with a helpful message when
-// LibreOffice is not installed.
-ipcMain.handle("folio:exportOdt", async () => {
-  try {
-    const bp = requireBook();
-    let filePath: string;
-    if (process.env.FOLIO_SELF_TEST === "1" && process.env.FOLIO_TEST_ODT) {
-      filePath = process.env.FOLIO_TEST_ODT;
-    } else {
-      const { canceled, filePath: chosen } = await showSaveDialog({
-        title: "Export Full Book as ODT",
-        defaultPath: `${currentBookTitle()}.odt`,
-        filters: [{ name: "OpenDocument Text", extensions: ["odt"] }],
-      });
-      if (canceled || !chosen) return { canceled: true } as const;
-      filePath = chosen.endsWith(".odt") ? chosen : `${chosen}.odt`;
-    }
-    const buf = await buildOdt(bp);
-    fs.writeFileSync(filePath, buf);
-    const odtOk = buf.length > 0 && buf.subarray(0, 2).toString("utf-8") === "PK";
-    return { ok: true, filePath, bytes: buf.length, odtOk };
-  } catch (e) {
-    return { error: (e as Error).message };
-  }
-});
+ipcMain.handle("folio:exportDocx", () => exportOffice("docx"));
+ipcMain.handle("folio:exportOdt", () => exportOffice("odt"));
 
 ipcMain.handle("folio:saveChapter", (_e, id: string, content: string) => {
   try {

src/main/office-export.ts

@@ -29,7 +29,7 @@ import {
   TextRun,
   WidthType,
 } from "docx";
-import { loadBook } from "./project.js";
+import { loadBook, type ChapterEntry } from "./project.js";
 import { listChaptersInOrder, loadChapterDoc } from "./chapters.js";
 import type { FolioMark, FolioNode } from "./native-doc.js";
 
@@ -422,13 +422,17 @@ function renderImage(node: FolioNode, bookPath: string): Paragraph {
   });
 }
 
-// Assemble the manuscript directly from native chapter documents, in canonical
-// chapter order. The book title leads, then each chapter (prepending a title
-// heading only when the content does not already carry one). A small spacer
-// before chapters after the first keeps the on-paper rhythm of the editor.
-export function buildDocx(bookPath: string): Promise<Buffer> {
+// Assemble the manuscript directly from native chapter documents. The chapters
+// to include are passed in explicitly (in canonical order) so the same ordered
+// list drives every export format — the single source of truth for ordering.
+// When omitted, the whole book (in stored order) is used for backward
+// compatibility. The book title leads, then each chapter (prepending a title
+// heading only when the content does not already carry one). Each chapter after
+// the first begins on a new page; the first chapter keeps its natural position
+// so no blank page is emitted up front.
+export function buildDocx(bookPath: string, chapters?: ChapterEntry[]): Promise<Buffer> {
   const meta = loadBook(bookPath);
-  const chapters = listChaptersInOrder(meta);
+  const used = chapters && chapters.length ? chapters : listChaptersInOrder(meta);
   const blocks: BlockEl[] = [
     new Paragraph({
       heading: HeadingLevel.TITLE,
@@ -443,7 +447,8 @@ export function buildDocx(bookPath: string): Promise<Buffer> {
     }),
   ];
 
-  chapters.forEach((ch, ci) => {
+  let rendered = 0;
+  used.forEach((ch) => {
     let doc: FolioNode;
     try {
       doc = loadChapterDoc(bookPath, ch.id).doc;
@@ -456,10 +461,14 @@ export function buildDocx(bookPath: string): Promise<Buffer> {
       : content;
 
     if (chapterBlocks.length) {
-      if (ci > 0) {
-        blocks.push(new Paragraph({ children: [], spacing: { before: 320, after: 0 } }));
+      if (rendered > 0) {
+        // Real page break between chapters (not just whitespace).
+        blocks.push(
+          new Paragraph({ pageBreakBefore: true, spacing: { before: 0, after: 0 }, children: [] })
+        );
       }
       blocks.push(...renderNodes(chapterBlocks, bookPath));
+      rendered += 1;
     }
   });
 
@@ -502,8 +511,8 @@ export function buildDocx(bookPath: string): Promise<Buffer> {
 // Convert the generated DOCX to ODT with LibreOffice running headless. This
 // keeps the two exports consistent and produces a spec-compliant ODT without
 // hand-writing a second XML vocabulary.
-export async function buildOdt(bookPath: string): Promise<Buffer> {
-  const docxBuf = await buildDocx(bookPath);
+export async function buildOdt(bookPath: string, chapters?: ChapterEntry[]): Promise<Buffer> {
+  const docxBuf = await buildDocx(bookPath, chapters);
   const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "folio-odt-"));
   try {
     const tmpDocx = path.join(tmpDir, "book.docx");

tests/run-office-export-test.mjs

@@ -206,7 +206,16 @@ check("docx body size is 12pt (24 half-points)", /<w:sz w:val="24"\/>/.test(docx
 // paragraphs. Attributes may be emitted in any order, so match loosely.
 check("docx has 1.7 line spacing", /<w:spacing[^>]*w:line="408"[^>]*w:lineRule="auto"[^>]*\/>/.test(docxXml));
 check("docx has blank-line paragraph spacing", /<w:spacing[^>]*w:after="408"/.test(docxXml));
-check("docx has chapter break before later chapters", (docxXml.match(/w:before="320"/g) || []).length >= 4);
+// Each chapter after the first begins on a new page (a real w:pageBreakBefore),
+// and there must be no page break before the first chapter (no blank first page).
+const pageBreaks = docxXml.match(/<w:pageBreakBefore\/>/g) || [];
+check("docx has a page break before later chapters", pageBreaks.length >= 4);
+const firstBreak = docxXml.indexOf("<w:pageBreakBefore/>");
+const titleIdx = docxXml.indexOf("Office Test Book");
+check(
+  "docx page breaks come after the book title (no blank first page)",
+  firstBreak === -1 || firstBreak > titleIdx
+);
 check("docx has callout shading", /w:fill="F5F2ED"/.test(docxXml));
 check("docx renders highlight (no raw markup)", !docxText.includes("==highlight=="));
 check("docx renders bold (no raw markup)", !docxText.includes("**bold**"));