feat: spellcheck menu, typewriter mode, file associations, updater hardening

English spellcheck suggestions with Add-to-dictionary in the native context menu plus a Settings toggle. Typewriter caret-centering mode. OS file associations for .md/.txt and Open File wording. Updater: release URL surfaced, single progress listener, two-byte tarball check, installer wait guard. Search/installer test suites registered; chapter-list layout polish; ignore KDE .directory files.

.gitignore

@@ -4,6 +4,7 @@ dist/
 *.asar
 releases/
 .DS_Store
+.directory
 tests/.tmp-folio-format-*.mjs
 
 .opencode/

electron-builder.yml

@@ -22,6 +22,25 @@ linux:
     - AppImage
     - deb
 
+# OS file associations: double-click / "Open with Folio" on Markdown and
+# plain-text files imports them as books (see folio:openPathOrImport and
+# fileArgFrom in src/main/index.ts). Without this the desktop environment
+# never offers Folio for .txt/.md files.
+fileAssociations:
+  - ext:
+      - md
+      - markdown
+    name: Folio Markdown document
+    description: Markdown document opened as a Folio book
+    role: Editor
+    mimeType: text/markdown
+  - ext:
+      - txt
+    name: Folio text document
+    description: Plain-text document opened as a Folio book
+    role: Editor
+    mimeType: text/plain
+
 # Debian package options live at the config root in electron-builder v26.
 # Setting `depends` replaces the auto-generated list, so keep its entries and
 # add what Electron links but the defaults omit — notably libasound2 (ALSA),

package.json

@@ -15,7 +15,7 @@
     "dev": "concurrently -k \"npm run build:watch\" \"wait-on dist/main.js && npm run electron\"",
     "start": "npm run build && npm run electron",
     "lint": "tsc --noEmit",
-    "test": "node tests/run-project-test.mjs && node tests/run-chapters-test.mjs && node tests/run-wikilinks-test.mjs && node tests/run-office-export-test.mjs && node tests/run-migration-test.mjs && node tests/run-editor-test.mjs && node tests/run-fullbook-test.mjs && node tests/run-print-test.mjs && node tests/run-update-import-test.mjs",
+    "test": "node tests/run-project-test.mjs && node tests/run-chapters-test.mjs && node tests/run-wikilinks-test.mjs && node tests/run-office-export-test.mjs && node tests/run-migration-test.mjs && node tests/run-editor-test.mjs && node tests/run-fullbook-test.mjs && node tests/run-print-test.mjs && node tests/run-update-import-test.mjs && node tests/run-update-installer-test.mjs && node tests/run-snapshots-test.mjs && node tests/run-search-test.mjs",
     "package": "electron-builder"
   },
   "devDependencies": {

src/main/index.ts

@@ -1,4 +1,4 @@
-import { app, BrowserWindow, clipboard, dialog, ipcMain, Menu, shell } from "electron";
+import { app, BrowserWindow, clipboard, dialog, ipcMain, Menu, session, shell } from "electron";
 import type { OpenDialogOptions, SaveDialogOptions } from "electron";
 import fs from "fs";
 import path from "path";
@@ -86,8 +86,8 @@ function createWindow() {
   mainWindow = new BrowserWindow({
     width: 1280,
     height: 780,
-    minWidth: 960,
+    minWidth: 560,
-    minHeight: 640,
+    minHeight: 400,
     title: "Folio",
     icon: path.join(__dirname, "icons", "icon.png"),
     webPreferences: {
@@ -97,6 +97,7 @@ function createWindow() {
     },
   });
   forwardEditShortcuts(mainWindow);
+  wireContextMenu(mainWindow);
   mainWindow.loadFile(path.join(__dirname, "index.html"));
   mainWindow.webContents.on("did-finish-load", () => {
     console.log("[folio] renderer loaded");
@@ -127,6 +128,15 @@ function createWindow() {
 
 app.whenReady().then(() => {
   migrateLegacyRecents();
+  // English-only spellcheck dictionary + stored on/off preference.
+  try {
+    session.defaultSession.setSpellCheckerLanguages(["en-US"]);
+    if (getSetting<boolean>("spellcheckEnabled", true) === false) {
+      session.defaultSession.setSpellCheckerEnabled(false);
+    }
+  } catch (err) {
+    console.error("[folio] spellchecker setup failed:", (err as Error).message);
+  }
   buildMenu(
     getWindow,
     getState,
@@ -710,19 +720,57 @@ handleIpc("folio:toggleFullscreen", () => {
   return win.isFullScreen();
 });
 
-// Right-click context menu (Electron has none by default), so Cut/Copy/Paste
+// Right-click menu with spelling suggestions (English-only dictionary).
-// via the mouse work. The roles act on whatever element is focused.
+// Electron builds no default context menu, so without this the red
-ipcMain.on("folio:context-menu", (event, x: number, y: number) => {
+// misspelling underlines had no way to reach a suggestion. Chromium reports
-  const win = BrowserWindow.fromWebContents(event.sender);
+// the misspelled word + candidates via the webContents event; suggestions
-  if (!win) return;
+// replace the word in place, and "Add to dictionary" persists to the
-  const menu = Menu.buildFromTemplate([
+// session's custom words.
+function wireContextMenu(win: BrowserWindow) {
+  win.webContents.on("context-menu", (_e, params) => {
+    const target = getWindow();
+    if (!target) return;
+    const items: Electron.MenuItemConstructorOptions[] = [];
+    if (params.misspelledWord) {
+      const sugs = (params.dictionarySuggestions || []).slice(0, 5);
+      if (sugs.length) {
+        for (const s of sugs) {
+          items.push({ label: s, click: () => target.webContents.replaceMisspelling(s) });
+        }
+      } else {
+        items.push({ label: "(no suggestions)", enabled: false });
+      }
+      items.push({
+        label: "Add to dictionary",
+        click: () =>
+          target.webContents.session.addWordToSpellCheckerDictionary(params.misspelledWord),
+      });
+      items.push({ type: "separator" });
+    }
+    items.push(
       { role: "cut" },
       { role: "copy" },
       { role: "paste" },
       { type: "separator" },
-    { role: "selectAll" },
+      { role: "selectAll" }
-  ]);
+    );
-  menu.popup({ window: win, x, y });
+    Menu.buildFromTemplate(items).popup({ window: target, x: params.x, y: params.y });
+  });
+}
+
+// Spellcheck preference (English-only dictionary). Applied at startup and
+// toggled live from Settings; the editor's spellcheck attribute stays on so
+// Chromium underlines misspellings whenever the session checker is enabled.
+handleIpc("folio:getSpellcheck", () => getSetting<boolean>("spellcheckEnabled", true));
+handleIpc("folio:setSpellcheck", (_e, on: unknown) => {
+  const enabled = on !== false;
+  setSetting("spellcheckEnabled", enabled);
+  try {
+    session.defaultSession.setSpellCheckerEnabled(enabled);
+  } catch {
+    // applied on next launch if the session is not ready yet
+  }
+  return { ok: true, enabled };
 });
 
 // Theme preference. Stored as a plain string so future themes can be added
@@ -901,9 +949,9 @@ handleIpc("folio:importAttachment", async () => {
 // never modified. Books land in Documents, same as "New".
 handleIpc("folio:importMarkdown", async () => {
   const { canceled, filePaths } = await showOpenDialog({
-    title: "Open Markdown file(s)",
+    title: "Open Markdown or text file(s)",
     properties: ["openFile", "multiSelections"],
-    filters: [{ name: "Markdown", extensions: ["md", "markdown", "txt"] }],
+    filters: [{ name: "Markdown and text", extensions: ["md", "markdown", "txt"] }],
   });
   if (canceled || !filePaths.length) return { canceled: true } as const;
   return importMarkdownFiles(filePaths, app.getPath("documents"));
@@ -956,6 +1004,7 @@ interface UpdateCheckResult {
   updateAvailable?: boolean;
   assetName?: string;
   notes?: string;
+  url?: string;
   canInstall?: boolean;
   error?: string;
 }
@@ -983,6 +1032,7 @@ handleIpc("folio:checkUpdate", async (): Promise<UpdateCheckResult> => {
       updateAvailable: isNewer(rel.version, current),
       assetName: asset ? asset.name : undefined,
       notes: rel.notes,
+      url: rel.url,
       canInstall:
         !!asset &&
         isTrustedDownloadUrl(asset.browser_download_url, updateConfig().base) &&
@@ -1035,7 +1085,21 @@ handleIpc("folio:performUpdate", async () => {
       getWindow()?.webContents.send("folio:update-progress", { received, total });
     });
     await pipeline(source, createWriteStream(tarball));
-    const head = fs.readFileSync(tarball).subarray(0, 2);
+    // Verify the gzip magic (2 bytes) without loading a ~100MB tarball into
+    // memory. Anything else means a truncated download or an HTML error page.
+    let head = Buffer.alloc(0);
+    try {
+      const fd = fs.openSync(tarball, "r");
+      try {
+        const buf = Buffer.alloc(2);
+        const n = fs.readSync(fd, buf, 0, 2, 0);
+        head = buf.subarray(0, n);
+      } finally {
+        fs.closeSync(fd);
+      }
+    } catch {
+      head = Buffer.alloc(0);
+    }
     if (head.length < 2 || head[0] !== 0x1f || head[1] !== 0x8b) {
       fs.rmSync(tarball, { force: true });
       return { error: "Downloaded file is not a valid archive; update aborted." };

src/main/menu.ts

@@ -1,8 +1,7 @@
 import path from "path";
-import { app, dialog, Menu, BrowserWindow } from "electron";
+import { app, Menu, BrowserWindow } from "electron";
 import { listRecents } from "./recents.js";
 import type { Recent } from "./recents.js";
-import { setRecoveryRoot } from "./backup.js";
 
 type MenuItem = Electron.MenuItemConstructorOptions;
 type GetState = () => { bookPath: string | null };
@@ -39,7 +38,7 @@ export function buildMenu(
        { label: "New", accelerator: "CmdOrCtrl+N", click: onRequestNew },
        { label: "Open", accelerator: "CmdOrCtrl+O", click: onRequestOpen },
         {
-         label: "Open Markdown File…",
+          label: "Open File…",
           click: () => getWindow()?.webContents.send("folio:open-markdown-requested"),
         },
        { type: "separator" },

src/main/preload.ts

@@ -10,8 +10,10 @@ contextBridge.exposeInMainWorld("folio", {
   revealInFolder: (p: string) => ipcRenderer.invoke("folio:reveal", p),
   getRecents: () => ipcRenderer.invoke("folio:getRecents"),
   closeBook: () => ipcRenderer.invoke("folio:closeBook"),
-  showContextMenu: (x: number, y: number) =>
+
-    ipcRenderer.send("folio:context-menu", x, y),
+  // spelling (English dictionary, suggestions in the native context menu)
+  getSpellcheck: () => ipcRenderer.invoke("folio:getSpellcheck"),
+  setSpellcheck: (on: boolean) => ipcRenderer.invoke("folio:setSpellcheck", on),
 
   // chapters
   getBookMeta: () => ipcRenderer.invoke("folio:getBookMeta"),

src/main/update.ts

@@ -146,7 +146,7 @@ export function buildInstallerScript(spec: InstallerSpec): string {
     `OLD="$INSTALL.old.$$"`,
     "# Wait (bounded to ~2 minutes) for the app process to exit.",
     "i=0",
-    'while kill -0 "$PID" 2>/dev/null && [ "$i" -lt 400 ]; do sleep 0.3; i=$((i+1)); done',
+    'while [ "$PID" -gt 0 ] 2>/dev/null && kill -0 "$PID" 2>/dev/null && [ "$i" -lt 400 ]; do sleep 0.3; i=$((i+1)); done',
     'rm -rf "$NEW"',
     'mkdir -p "$NEW"',
     'if tar -xzf "$TARBALL" -C "$NEW"; then',

src/renderer/book/chapter-list.ts

@@ -151,7 +151,6 @@ export function createChapterListFeature(ctx: BookCtx): ChapterListFeature {
       li.draggable = false;
       li.tabIndex = -1;
       li.innerHTML = `
-        <span class="drag-handle" title="Drag to reorder">⋮</span>
         <span class="row-title" title="${ch.title}">${ch.title}</span>
         <span class="row-actions">
           <button class="icon-btn" data-act="color" title="Chapter color">●</button>

src/renderer/book/editor.ts

@@ -51,6 +51,45 @@ export function createEditorFeature(ctx: BookCtx): EditorFeature {
   });
   const editorHost = $("editorHost");
 
+  // ---- typewriter mode ----
+  // Keeps the caret near 42% of the visible editor height by scrolling the
+  // ProseMirror surface (which is its own scroll container) as the selection
+  // moves. Renderer-local preference; nothing leaves the machine.
+  const TYPEWRITER_KEY = "folio:typewriter";
+  let typewriterOn = false;
+  try {
+    typewriterOn = localStorage.getItem(TYPEWRITER_KEY) === "1";
+  } catch {
+    typewriterOn = false;
+  }
+  function setTypewriterEnabled(on: boolean) {
+    typewriterOn = on !== false;
+    try {
+      localStorage.setItem(TYPEWRITER_KEY, typewriterOn ? "1" : "0");
+    } catch {
+      // private-mode storage failure: mode still applies for the session
+    }
+    if (typewriterOn) centerCaret();
+  }
+  function isTypewriterEnabled(): boolean {
+    return typewriterOn;
+  }
+  function centerCaret() {
+    if (!typewriterOn || !editor.isFocused) return;
+    if (!editor.state.selection.empty) return;
+    const scroller = editor.view.dom as HTMLElement;
+    const rect = scroller.getBoundingClientRect();
+    if (rect.height <= 0) return;
+    let y = 0;
+    try {
+      y = editor.view.coordsAtPos(editor.state.selection.from).top;
+    } catch {
+      return;
+    }
+    const dy = y - (rect.top + rect.height * 0.42);
+    if (Math.abs(dy) > 2) scroller.scrollTop += dy;
+  }
+
   // The ProseMirror surface is narrower than its host for readable line
   // lengths. Keep the surrounding editor area clickable so a new chapter can
   // be focused without requiring a click on the centered content column.
@@ -239,6 +278,8 @@ export function createEditorFeature(ctx: BookCtx): EditorFeature {
     setActive("align-left", fmt.align === "left" || fmt.align === "");
     setActive("align-center", fmt.align === "center");
     setActive("align-right", fmt.align === "right");
+    // Defer to the next frame so coords reflect the updated layout.
+    if (typewriterOn) requestAnimationFrame(centerCaret);
   }
 
   // Ctrl/Cmd+S saves the current chapter (in addition to the menu item).

src/renderer/book/index.ts

@@ -144,6 +144,7 @@ export function initBook(api: FolioAPI) {
   // server, then offer a one-click install. The app downloads the tarball,
   // hands off to a detached swap script, and relaunches itself — no manual
   // reinstall. See src/main/update.ts for the safety properties.
+  let updateProgressWired = false;
   async function checkForUpdates() {
     showToast("Checking for updates…");
     const res = await api.checkUpdate();
@@ -164,18 +165,23 @@ export function initBook(api: FolioAPI) {
     if (!res.canInstall) {
       await alertMessage(
         "Automatic install unavailable",
-        "This release has no installable Linux archive, or this Folio is not the user-local install. Download it manually from the releases page."
+        "This release has no installable Linux archive, or this Folio is not the user-local install." +
+          (res.url ? ` Download it manually from ${res.url}` : " Download it manually from the releases page.")
       );
       return;
     }
+    // Registered once: checkForUpdates can run repeatedly per session and
+    // ipcRenderer.on would otherwise stack duplicate progress listeners.
+    if (!updateProgressWired) {
+      updateProgressWired = true;
       let lastPct = -1;
       api.onUpdateProgress(({ received, total }) => {
         const pct = total ? Math.floor((received / total) * 100) : -1;
-      if (pct !== lastPct) {
+        if (pct === lastPct) return;
         lastPct = pct;
         showToast(pct >= 0 ? `Downloading update… ${pct}%` : `Downloading update… ${(received / 1048576).toFixed(1)} MB`);
-      }
       });
+    }
     const up = await api.performUpdate();
     if (up && up.error) {
       await alertMessage("Update failed", up.error);

src/renderer/book/toolbar.ts

@@ -201,17 +201,10 @@ export function createToolbarFeature(ctx: BookCtx, editor: Editor): ToolbarFeatu
   // any of those closes the dropdowns.
   window.addEventListener("scroll", closeDropdowns, true);
   window.addEventListener("resize", closeDropdowns);
-  // Electron has no default right-click menu, so show one with Cut/Copy/Paste.
+  // Note: right-click is handled by the main process (webContents
-  window.addEventListener("contextmenu", (e) => {
+  // context-menu with spelling suggestions + Cut/Copy/Paste), so no DOM
-    // Let Chromium show its native spelling suggestions when the target is a
+  // contextmenu listener here — preventing the default would suppress the
-    // misspelled word. The custom menu is used for the rest of the editor.
+  // native suggestion menu for misspelled words.
-    const target = e.target as HTMLElement | null;
-    if (target?.closest(".ProseMirror") && window.getSelection()?.isCollapsed) {
-      return;
-    }
-    e.preventDefault();
-    api.showContextMenu(e.clientX, e.clientY);
-  });
 
   const headingSelect = $("headingSelect") as HTMLSelectElement;
   headingSelect.addEventListener("change", () => {

src/renderer/book/types.ts

@@ -39,7 +39,8 @@ export type FolioAPI = {
   revealInFolder: (p: string) => Promise<boolean>;
   getRecents: () => Promise<any[]>;
   closeBook: () => Promise<boolean>;
-  showContextMenu: (x: number, y: number) => void;
+  getSpellcheck: () => Promise<boolean>;
+  setSpellcheck: (on: boolean) => Promise<any>;
   getBookMeta: () => Promise<BookMeta | { error: string }>;
   setComments: (comments: Record<string, unknown>) => Promise<any>;
   getChapterList: () => Promise<any[]>;

src/renderer/index.css

@@ -44,23 +44,29 @@ html, body {
   color: var(--color-text);
   -webkit-font-smoothing: antialiased;
   -moz-osx-font-smoothing: grayscale;
+  overflow: hidden;
+  max-width: 100vw;
 }
 
 #root {
   display: flex;
   height: 100vh;
+  width: 100vw;
+  max-width: 100vw;
   overflow: hidden;
 }
 
 .sidebar {
   flex: 0 0 280px;
   min-width: 240px;
-  max-width: 360px;
+  max-width: min(360px, 85vw);
+  flex-shrink: 0;
   background: var(--color-panel);
   border-right: 1px solid var(--color-border);
   display: flex;
   flex-direction: column;
   padding: var(--gap);
+  overflow-x: clip;
 }
 
 .sidebar-header {
@@ -342,8 +348,10 @@ html, body {
 .editor {
   flex: 1;
   display: flex;
+  min-width: 0;
+  max-width: 100%;
   background: var(--color-bg);
-  overflow: visible;
+  overflow: hidden;
 }
 
 .editor-placeholder {
@@ -716,23 +724,6 @@ body.dragging-active * {
   font-weight: 600;
 }
 
-.drag-handle {
-  cursor: grab;
-  padding: 4px 6px;
-  font-size: 1.05rem;
-  line-height: 1;
-  color: var(--color-muted);
-  opacity: 0.6;
-  border-radius: 4px;
-  transition: opacity 0.12s ease, color 0.12s ease;
-  user-select: none;
-}
-
-.chapter-row:hover .drag-handle {
-  opacity: 0.9;
-  color: var(--color-on-accent);
-}
-
 .row-title {
   flex: 1;
   overflow: hidden;
@@ -909,6 +900,7 @@ body.dragging-active * {
   flex: 1;
   display: flex;
   flex-direction: column;
+  min-width: 0;
   padding: 0;
   overflow: hidden;
 }
@@ -917,17 +909,22 @@ body.dragging-active * {
   flex: 1;
   display: flex;
   flex-direction: column;
+  min-width: 0;
   padding: 0;
   overflow: hidden;
 }
 
 .chapter-header {
   display: flex;
-  align-items: baseline;
+  align-items: center;
   justify-content: space-between;
   gap: 12px;
   padding: 14px 20px;
   border-bottom: 1px solid var(--color-border);
+  flex-wrap: wrap;
+  min-width: 0;
+  max-width: 100%;
+  overflow-x: clip;
 }
 
 .chapter-title {
@@ -936,6 +933,11 @@ body.dragging-active * {
   font-weight: 600;
   margin: 0;
   color: var(--color-text);
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  flex: 1 1 auto;
 }
 
 .word-count {
@@ -946,6 +948,11 @@ body.dragging-active * {
 .editor-actions {
   display: flex;
   align-items: center;
+  flex-wrap: wrap;
+  row-gap: 6px;
+  justify-content: flex-end;
+  min-width: 0;
+  max-width: 100%;
   gap: 10px;
   color: var(--color-muted);
   font-size: 0.72rem;
@@ -1156,9 +1163,13 @@ body.dragging-active * {
 .editor-toolbar {
   display: flex;
   align-items: center;
-  flex-wrap: nowrap;
+  align-content: flex-start;
-  overflow: visible;
+  flex-wrap: wrap;
+  overflow-x: clip;
+  max-width: 100%;
+  min-width: 0;
   gap: 4px;
+  row-gap: 6px;
   padding: 6px 12px;
   border-bottom: 1px solid var(--color-border);
   background: var(--color-panel);
@@ -1170,11 +1181,15 @@ body.dragging-active * {
 .toolbar-group {
   display: flex;
   align-items: center;
+  flex-wrap: wrap;
+  row-gap: 6px;
   gap: 2px;
   padding-right: 8px;
   margin-right: 8px;
   border-right: 1px solid var(--color-border);
-  flex: 0 0 auto;
+  flex: 0 1 auto;
+  min-width: 0;
+  max-width: 100%;
 }
 
 .toolbar-group:last-child {
@@ -1991,3 +2006,40 @@ body:not(.dragging-active) .chapter-row {
     animation: none !important;
   }
 }
+
+/* ---- narrow / tiled windows (Hyprland split-screen etc.) ----
+   Below ~900px the sidebar + full header + toolbar can't fit side by side,
+   so shrink the chrome instead of overflowing past the tile edge. */
+@media (max-width: 900px) {
+  .sidebar {
+    flex-basis: 220px;
+    min-width: 200px;
+  }
+  .brand-icon {
+    width: 48px;
+    height: 48px;
+  }
+  .chapter-header {
+    padding: 10px 12px;
+  }
+  .editor-toolbar {
+    padding: 6px 8px;
+  }
+  .toolbar-select {
+    max-width: 110px;
+  }
+  .toolbar-group {
+    padding-right: 6px;
+    margin-right: 6px;
+  }
+}
+
+@media (max-width: 640px) {
+  .sidebar {
+    flex-basis: 200px;
+    min-width: 180px;
+  }
+  .chapter-title {
+    font-size: 1.15rem;
+  }
+}

src/renderer/index.html

@@ -57,7 +57,7 @@
           <div class="welcome-actions">
             <button class="button" id="welcomeNewBook">New</button>
             <button class="button button-ghost" id="welcomeOpenBook">Open</button>
-            <button class="button button-ghost" id="welcomeOpenMd" title="Open a Markdown file as a new book">Open .md</button>
+            <button class="button button-ghost" id="welcomeOpenMd" title="Open a Markdown or text file as a new book">Open file</button>
             <button class="button button-ghost" id="welcomeUpdate" title="Check for a new version of Folio">Update</button>
           </div>
           <div class="recents-block">

tests/run-search-test.mjs

@@ -0,0 +1,41 @@
+// Standalone test for the whole-book search helpers (src/renderer/book/ui.ts).
+// These pure functions power the Search modal: Markdown flattening, literal
+// matching (phrases included), and result snippets.
+// Run with: node tests/run-search-test.mjs
+import { bundleForTest } from "./helpers/bundle.mjs";
+
+const { mod: ui, cleanupBundle } = await bundleForTest({
+  name: "folio-search-ui",
+  entryPoints: ["src/renderer/book/ui.ts"],
+});
+const { findMatches, markdownToPlain, makeSnippet, moveInList, escapeHtml } = ui;
+
+let failures = 0;
+function ok(cond, msg) {
+  if (cond) console.log("  ok -", msg);
+  else { failures++; console.error("FAIL -", msg); }
+}
+
+// markdown -> searchable plain text
+ok(markdownToPlain("# Title\nSome **bold** text") === "Title\nSome bold text", "headings/emphasis flattened");
+ok(markdownToPlain("[link](http://x)") === "link", "links flattened to text");
+ok(markdownToPlain("`code`") === "code", "inline code flattened");
+
+// literal matching incl. phrases, case handling
+ok(JSON.stringify(findMatches("hello world hello", "hello", true)) === "[0,12]", "finds all occurrences");
+ok(findMatches("Hello", "hello", true).length === 0, "match-case respected");
+ok(findMatches("Hello", "hello", false).length === 1, "case-insensitive match");
+ok(JSON.stringify(findMatches("the quick brown fox", "quick brown", false)) === "[4]", "phrase search works");
+ok(findMatches("a.b", "a.b", false).length === 1, "regex chars treated literally");
+
+// snippets highlight the match and escape HTML
+const snip = makeSnippet("say <hi> & bye", 4, 4);
+ok(snip.includes("<mark>") && snip.includes("&lt;hi&gt;"), "snippet highlights + escapes");
+
+// shared reorder math used by drag + keyboard reorder
+ok(JSON.stringify(moveInList([1, 2, 3], 0, 2)) === "[2,3,1]", "moveInList moves item");
+ok(escapeHtml("<a>&") === "&lt;a&gt;&amp;", "escapeHtml works");
+
+cleanupBundle();
+if (failures) { console.error(`${failures} search check(s) FAILED`); process.exit(1); }
+console.log("All search checks passed.");

tests/run-update-import-test.mjs

@@ -44,6 +44,37 @@ assert(sh.includes(`'/tmp/it'\\''s.tar.gz'`), "shQuote escapes embedded single q
 assert(sh.includes("kill -0"), "installer waits for app pid");
 assert(sh.includes("-xzf"), "installer extracts gz");
 
+// Real Gitea release-JSON shape (tag_name/html_url/body/assets with sizes).
+const gitea = u.parseRelease({
+  id: 5,
+  tag_name: "v0.2.0",
+  html_url: "https://git.atitlan.io/avi/Folio/releases/tag/v0.2.0",
+  body: "Bug fixes",
+  assets: [
+    { name: "Folio-0.2.0-linux-x86_64.tar.gz", browser_download_url: "https://git.atitlan.io/avi/Folio/releases/download/v0.2.0/Folio-0.2.0-linux-x86_64.tar.gz", size: 123456 },
+    { name: "Folio-0.2.0-linux-amd64.deb", browser_download_url: "https://git.atitlan.io/avi/Folio/releases/download/v0.2.0/Folio-0.2.0-linux-amd64.deb", size: 111 },
+    { name: "Folio-0.2.0.AppImage", browser_download_url: "https://git.atitlan.io/avi/Folio/releases/download/v0.2.0/Folio-0.2.0.AppImage", size: 222 },
+  ],
+});
+assert(gitea.version === "0.2.0", "gitea tag parsed");
+assert(gitea.url === "https://git.atitlan.io/avi/Folio/releases/tag/v0.2.0", "gitea release url kept");
+assert(gitea.notes === "Bug fixes", "gitea notes kept");
+assert(u.pickAsset(gitea.assets).name.endsWith(".tar.gz"), "gitea: tar.gz picked over deb/AppImage");
+assert(u.isTrustedDownloadUrl(gitea.assets[0].browser_download_url, "https://git.atitlan.io"), "gitea asset url trusted");
+
+// No installable archive cases.
+assert(u.pickAsset([]) === null, "empty assets -> no pick");
+const debOnly = u.parseRelease({ tag_name: "v0.3.0", assets: [{ name: "Folio.deb", browser_download_url: "https://git.atitlan.io/x/Folio.deb" }] });
+assert(u.pickAsset(debOnly.assets) === null, "deb-only release -> no pick (tar.gz required)");
+
+// Version edge cases.
+assert(!u.isNewer("0.1.0", "0.1.0"), "same version not an update");
+assert(!u.isNewer("0.1.0", "0.2.0"), "older release not an update");
+assert(u.compareVersions("0.1.2-rc1", "0.1.2") === 0, "rc suffix ignored in compare");
+assert(u.parseVersion("nope") === null, "unparseable version -> null");
+assert(!u.isTrustedDownloadUrl("http://git.atitlan.io/a.tar.gz", "https://git.atitlan.io"), "http vs https rejected");
+assert(!u.isTrustedDownloadUrl("not a url", "https://git.atitlan.io"), "malformed url rejected");
+
 assert(m.mdTitle("# My Heading\nbody", "file") === "My Heading", "title from H1");
 assert(m.mdTitle("no heading", "file") === "file", "title falls back to filename stem");
 

tests/run-update-installer-test.mjs

@@ -0,0 +1,123 @@
+// Sandbox execution test for the updater handoff script (buildInstallerScript).
+// Runs the generated /bin/sh script against fake install dirs in os.tmpdir() —
+// never the real ~/.local/share/Folio — proving the swap works and failures
+// always relaunch the OLD version.
+// Run with: node tests/run-update-installer-test.mjs
+import { execFileSync, spawn } from "child_process";
+import fs from "fs";
+import os from "os";
+import path from "path";
+import url from "url";
+import { bundleForTest } from "./helpers/bundle.mjs";
+
+const { mod: u, cleanupBundle } = await bundleForTest({
+  name: "folio-update-script",
+  entryPoints: ["src/main/update.ts"],
+});
+
+let fails = 0;
+function ok(cond, msg) {
+  if (cond) console.log("  ok -", msg);
+  else { fails++; console.error("FAIL -", msg); }
+}
+
+function sleepPid(ms) {
+  // Short-lived stand-in for the app process the script waits on.
+  const p = spawn("sleep", [String(ms / 1000)], { stdio: "ignore" });
+  return p.pid;
+}
+
+// A pid that is dead AND reaped (kill -0 fails), so the script proceeds
+// without waiting. NOTE: a Node-spawned child that just exited stays a
+// zombie while our event loop is blocked inside execFileSync — and kill -0
+// succeeds on zombies — so the pid must be observed dead before running the
+// script, not merely spawned with a short sleep.
+async function deadPid() {
+  const p = spawn("sleep", ["0.01"], { stdio: "ignore" });
+  const pid = p.pid;
+  p.on("error", () => {});
+  for (let i = 0; i < 200; i++) {
+    try {
+      process.kill(pid, 0);
+    } catch {
+      return pid;
+    }
+    await new Promise((r) => setTimeout(r, 10));
+  }
+  throw new Error("helper process would not die");
+}
+
+function runScript(script, timeoutMs = 30000) {
+  execFileSync("/bin/sh", [script], { timeout: timeoutMs, stdio: "ignore" });
+}
+
+// Fake "installed" app tree: an executable `folio` stub + a data file.
+function makeInstall(box, versionMarker) {
+  const dir = path.join(box, "install");
+  fs.mkdirSync(dir, { recursive: true });
+  fs.writeFileSync(path.join(dir, "folio"), `#!/bin/sh\necho ${versionMarker}\n`, { mode: 0o755 });
+  fs.writeFileSync(path.join(dir, "other.txt"), "keepme");
+  return dir;
+}
+
+// Fake release tarball with an electron-builder-style nested top-level dir.
+function makeTarball(box, versionMarker) {
+  const staged = path.join(box, "staged", "Folio-linux-x64");
+  fs.mkdirSync(staged, { recursive: true });
+  fs.writeFileSync(path.join(staged, "folio"), `#!/bin/sh\necho ${versionMarker}\n`, { mode: 0o755 });
+  fs.writeFileSync(path.join(staged, "extra.txt"), "newfile");
+  const tarball = path.join(box, "release.tar.gz");
+  execFileSync("tar", ["-czf", tarball, "-C", path.join(box, "staged"), "Folio-linux-x64"]);
+  return tarball;
+}
+
+// Relaunch stub records that it was invoked.
+function makeRelaunch(box) {
+  const marker = path.join(box, "relaunched");
+  const launcher = path.join(box, "relaunch.sh");
+  fs.writeFileSync(launcher, `#!/bin/sh\ntouch ${JSON.stringify(marker)}\n`, { mode: 0o755 });
+  return { launcher, marker };
+}
+
+function writeScript(box, spec) {
+  const script = path.join(box, "installer.sh");
+  fs.writeFileSync(script, u.buildInstallerScript(spec), { mode: 0o700 });
+  return script;
+}
+
+// --- success path: valid tarball replaces the install, relaunches ---
+{
+  const box = fs.mkdtempSync(path.join(os.tmpdir(), "folio-upd-ok-"));
+  const install = makeInstall(box, "OLD");
+  const tarball = makeTarball(box, "NEW");
+  const { launcher, marker } = makeRelaunch(box);
+  const pid = await deadPid();
+  runScript(writeScript(box, { pid, tarball, installDir: install, relaunch: launcher }));
+  await new Promise((r) => setTimeout(r, 800)); // relaunched in background (&)
+  ok(fs.readFileSync(path.join(install, "folio"), "utf-8").includes("NEW"), "install swapped to new version");
+  ok(fs.readFileSync(path.join(install, "extra.txt"), "utf-8") === "newfile", "new files land in install");
+  ok(fs.existsSync(marker), "relaunch invoked after swap");
+  ok(!fs.existsSync(tarball), "tarball cleaned up after success");
+  ok(!fs.readdirSync(path.dirname(install)).some((e) => e.includes(".old.")), "old tree pruned after success");
+  fs.rmSync(box, { recursive: true, force: true });
+}
+
+// --- failure path: corrupt tarball keeps the old install, still relaunches ---
+{
+  const box = fs.mkdtempSync(path.join(os.tmpdir(), "folio-upd-bad-"));
+  const install = makeInstall(box, "OLD");
+  const tarball = path.join(box, "release.tar.gz");
+  fs.writeFileSync(tarball, "this is not a gzip stream");
+  const { launcher, marker } = makeRelaunch(box);
+  const pid = await deadPid();
+  runScript(writeScript(box, { pid, tarball, installDir: install, relaunch: launcher }));
+  await new Promise((r) => setTimeout(r, 800));
+  ok(fs.readFileSync(path.join(install, "folio"), "utf-8").includes("OLD"), "old install intact after bad tarball");
+  ok(fs.existsSync(marker), "relaunch still invoked after failure");
+  ok(!fs.readdirSync(path.dirname(install)).some((e) => e.includes(".old.")), "no .old residue after failure");
+  fs.rmSync(box, { recursive: true, force: true });
+}
+
+cleanupBundle();
+if (fails) { console.error(`${fails} installer check(s) FAILED`); process.exit(1); }
+console.log("All installer checks passed.");