Release version 0.6.1

.github/workflows/lint.yml

@@ -42,7 +42,11 @@ jobs:
               uses: actions/setup-node@v6
               with:
                   node-version: ${{ matrix.node-version }}
-                  cache: 'npm'
-            - run: npm ci
-            - run: npm run build --if-present
-            - run: npm run lint
+            # Node ships corepack, which selects the pnpm version pinned in
+            # package.json ("packageManager"). If this self-hosted runner has no
+            # Node, drop the setup-node step above and rely on a preinstalled Node.
+            - run: corepack enable
+            - run: pnpm install --frozen-lockfile
+            - run: pnpm run build
+            - run: pnpm run lint
+            - run: pnpm test

.github/workflows/release.yml

@@ -40,12 +40,17 @@ jobs:
               uses: actions/setup-node@v6
               with:
                   node-version: 24
-                  cache: 'npm'
+
+            # Node ships corepack, which selects the pnpm version pinned in
+            # package.json ("packageManager"). If this self-hosted runner has no
+            # Node, drop the setup-node step above and rely on a preinstalled Node.
+            - name: Enable pnpm
+              run: corepack enable
 
             - name: Build plugin
               run: |
-                  npm ci
-                  npm run build
+                  pnpm install --frozen-lockfile
+                  pnpm run build
 
             - name: Check for optional styles
               id: styles

.gitignore

@@ -41,3 +41,4 @@ data.json
 
 # Exclude macOS Finder (System Explorer) View States
 .DS_Store
+ZETTELCLEAN*

README.md

@@ -37,18 +37,26 @@ slug tail follows. Nothing else is touched.
 
 ## How it works
 
-- A note is a zettel when its filename starts with a **TIMEID**: a run of 12 to 18 digits
-  (a timestamp), for example `20260728145404-my-note.md`. Files without that prefix are
-  ignored, so plain notes, daily notes, Excalidraw and Kanban files are never renamed.
-- The TIMEID is minted **once** and never changes. Only the slug tail is regenerated.
-- When you edit the H1, zettelclean waits about 5 seconds of idle, then renames the file to
-  `TIMEID-slug(H1).md` using Obsidian's own rename (so backlinks are updated). A 10 second
+- A note is a zettel when its filename starts with a recognized **prefix**: a **TIMEID** (a run
+  of 12 to 18 digits) always, and a **`yyyy-mm-dd` date** too if you enable date mode in settings.
+  The prefix is followed by any non-digit or the end of the name - so `20260728145404-my-note.md`,
+  `202607281454.md`, `202607281454 my note.md`, and (date mode) `2026-07-30 Journal.md` all
+  qualify. Files without a recognized prefix are ignored, so plain notes, Excalidraw and Kanban
+  files are never renamed.
+- The prefix is fixed and never changes; only the slug tail is regenerated.
+- When you edit the H1, zettelclean waits about 4 seconds of idle, then renames the file to
+  `prefix-slug(H1).md` using Obsidian's own rename (so backlinks are updated). A 6 second
   cooldown prevents a just-renamed file from being renamed again.
 - Sync is strictly one-way, H1 to filename. Renaming a file by hand is never fought.
-- Delete the H1 and the filename collapses back to the bare `TIMEID.md`.
+- **Sticky tail:** the tail follows the H1 when it produces a slug; with no H1 the existing tail
+  is kept and cleaned. The tail is never deleted - delete the H1 and the filename keeps its last
+  slug. A note that never had a title stays bare (`TIMEID.md`); one with no usable title (empty
+  H1 and no sluggable tail) is left untouched.
+- If a rename would collide with an existing filename, zettelclean keeps the current name and
+  shows a notice.
 
-The slug is lowercase, ASCII, dash-separated: accents are folded (`Ciências` becomes
-`ciencias`), runs of punctuation and whitespace collapse to a single dash, and leading and
+The slug is case-preserving, ASCII, dash-separated: accents are folded (`Ciências` becomes
+`Ciencias`), runs of punctuation and whitespace collapse to a single dash, and leading and
 trailing dashes are trimmed.
 
 ## Creating notes
@@ -67,9 +75,22 @@ change the setting.
 ### Retrofitting existing notes
 
 Notes created before you adopted this workflow have no TIMEID. Right-click such a note in the
-file explorer and choose **"Add zettel TIMEID to filename"**. It mints a fresh timestamp,
+file explorer and choose **"Prefix timestamp to filename"**. It mints a fresh timestamp,
 prepends it, and the note is now a zettel that syncs on future H1 edits.
 
+### Date-prefixed notes (journaling)
+
+Turn on **date mode** in settings to also treat `yyyy-mm-dd`-prefixed notes as zettels. A daily
+note `2026-07-30.md` gains a slug once you title it (`# Gratitude` -> `2026-07-30-Gratitude.md`),
+and `2026-07-30 Morning pages.md` is cleaned to `2026-07-30-Morning-pages.md`.
+
+## Slugging a folder name
+
+Right-click a folder and choose **"Slug folder name"** to ASCII-clean it in place (this folder
+only): `Citações` becomes `Citacoes`. The rename goes through Obsidian, so `[[links]]` into the
+folder are updated. It aborts if a sibling of that name already exists, and never touches the
+vault root.
+
 ## Pretty sidebar (optional)
 
 By default the file explorer shows the slugged filename (with dashes). If you want the sidebar,
@@ -84,19 +105,52 @@ That reads the first H1 directly and falls back to the filename when there is no
 
 ## Settings
 
-None. Zettelclean is zero-config in this version. The 5 second settle and 10 second cooldown
-are fixed.
+One setting: **Recognized filename prefixes** (Settings -> Community plugins -> Zettelclean).
+
+- **Timestamp only** (default) - only 12-18 digit TIMEID prefixes.
+- **Timestamp and date** - also `yyyy-mm-dd` prefixes, for journaling.
+
+The 4 second settle and 6 second cooldown are fixed.
 
 ## Development
 
-- `npm install` (or `pnpm install`).
-- `npm run dev` - compile in watch mode.
-- `npm run build` - typecheck and produce `main.js`.
-- `npm test` - run the slug unit tests on Node's built-in test runner.
-- `npm run lint` - eslint with the Obsidian ruleset.
+Dependencies are managed with **pnpm** (see "Why pnpm, not npm" below). Node 22+ ships
+`corepack`, so you do not need to install pnpm globally, and the `packageManager` field in
+`package.json` pins the exact version.
+
+```bash
+corepack pnpm install     # first time, or after a dependency change
+corepack pnpm run dev     # compile in watch mode
+corepack pnpm run build   # typecheck and produce main.js
+corepack pnpm test        # run the slug unit tests (Node's built-in runner)
+corepack pnpm run lint    # eslint with the Obsidian ruleset
+```
 
 The pure string logic lives in `src/slug.ts` and is unit-tested in isolation; the Obsidian
-wiring lives in `src/main.ts`.
+wiring lives in `src/main.ts`. Tests run on Node's built-in test runner (`node --test`) - there
+is no vitest or jest dependency.
+
+### Why pnpm, not npm
+
+**Do not run `npm install` or `npm ci` in this repo.** This project is developed on a **ZFS**
+filesystem, and npm's installer renames many directories in parallel (to hoist and dedupe
+packages). That races ZFS's directory-metadata handling and aborts with:
+
+```
+npm error code ENOTEMPTY
+npm error syscall rename
+```
+
+pnpm avoids the problem entirely: it hard-links packages from a global content-addressable
+store instead of renaming directories into place, so it installs cleanly on the same disk.
+
+Notes for contributors:
+
+- Only `npm install` / `npm ci` are affected. Running *scripts* through npm (`npm run build`)
+  still works, because that just spawns tsc/esbuild and installs nothing. Still, prefer `pnpm`
+  everywhere for consistency.
+- The lockfile is `pnpm-lock.yaml` (committed). There is no `package-lock.json`; do not create
+  one.
 
 ## License
 

VERSION

@@ -1 +1 @@
-zettelclean v0.3
+zettelclean v0.6.1

manifest.json

@@ -1,7 +1,7 @@
 {
 	"id": "zettelclean",
 	"name": "Zettelclean",
-	"version": "0.3.0",
+	"version": "0.6.1",
 	"minAppVersion": "1.0.0",
 	"description": "Keep a Zettelkasten filename's slug in sync with the note's H1 heading.",
 	"author": "Ruben Carlo Benante",

package.json

@@ -1,10 +1,11 @@
 {
 	"name": "zettelclean",
-	"version": "0.3.0",
+	"version": "0.6.1",
 	"description": "Keep a Zettelkasten filename's slug in sync with the note's H1 heading.",
 	"author": "Ruben Carlo Benante <rcb@beco.cc>",
 	"main": "main.js",
 	"type": "module",
+	"packageManager": "pnpm@9.15.9",
 	"scripts": {
 		"dev": "node esbuild.config.mjs",
 		"build": "tsc -noEmit -skipLibCheck && node esbuild.config.mjs production",

src/main.ts

@@ -19,29 +19,52 @@
 // *  rcb@beco.cc                                                          *
 // *************************************************************************
 
-import { Plugin, TFile, TAbstractFile, Menu, moment } from 'obsidian';
-import { extractTimeId, generateSlug, buildFilename } from './slug';
+import {
+	Plugin,
+	TFile,
+	TAbstractFile,
+	TFolder,
+	Menu,
+	Notice,
+	moment,
+} from 'obsidian';
+import {
+	extractPrefix,
+	computeBasename,
+	generateSlug,
+	buildFilename,
+} from './slug';
+import {
+	ZettelcleanSettings,
+	DEFAULT_SETTINGS,
+	ZettelcleanSettingTab,
+} from './settings';
 
-const SETTLE_MS = 5000; // rename ~5s after the H1 stops changing
-const COOLDOWN_MS = 10000; // do not rename the same path again within 10s
+const SETTLE_MS = 4000; // rename ~4s after the H1 stops changing
+const COOLDOWN_MS = 6000; // do not rename the same path again within 6s
 
 export default class ZettelcleanPlugin extends Plugin {
+	settings!: ZettelcleanSettings;
 	private renameTimers = new Map<string, number>();
 	private lastRenamedAt = new Map<string, number>();
 	private isRenameInProgress = false;
 
 	async onload() {
+		await this.loadSettings();
+		this.addSettingTab(new ZettelcleanSettingTab(this.app, this));
+
 		// Fires after the metadata cache reparses a note, so headings[] is fresh.
 		this.registerEvent(
 			this.app.metadataCache.on('changed', (file) =>
 				this.scheduleSync(file),
 			),
 		);
-		// Retrofit entry in the file-explorer right-click menu, near "Rename".
+		// File-explorer right-click menu: retrofit item for files, slug item for folders.
 		this.registerEvent(
-			this.app.workspace.on('file-menu', (menu, file) =>
-				this.addTimeIdMenu(menu, file),
-			),
+			this.app.workspace.on('file-menu', (menu, file) => {
+				this.addTimeIdMenu(menu, file);
+				this.addFolderSlugMenu(menu, file);
+			}),
 		);
 	}
 
@@ -50,22 +73,35 @@ export default class ZettelcleanPlugin extends Plugin {
 		this.renameTimers.clear();
 	}
 
+	async loadSettings() {
+		this.settings = Object.assign(
+			{},
+			DEFAULT_SETTINGS,
+			(await this.loadData()) as Partial<ZettelcleanSettings>,
+		);
+	}
+
+	async saveSettings() {
+		await this.saveData(this.settings);
+	}
+
 	private pathFor(file: TFile, base: string): string {
 		const dir =
 			file.parent && file.parent.path !== '/' ? `${file.parent.path}/` : '';
 		return `${dir}${base}.md`;
 	}
 
-	// Guard layer: only the actively edited zettel, honoring the 10s cooldown,
-	// (re)arming the 5s settle timer on every cache change.
+	// Guard layer: only the actively edited zettel, honoring the 6s cooldown,
+	// (re)arming the 4s settle timer on every cache change.
 	private scheduleSync(file: TAbstractFile) {
 		if (this.isRenameInProgress) return; // our own rename, ignore
 		if (!(file instanceof TFile) || file.extension !== 'md') return;
-		if (extractTimeId(file.basename) === null) return; // opt-in gate: no TIMEID
+		const allowDate = this.settings.prefixMode === 'date';
+		if (extractPrefix(file.basename, allowDate) === null) return; // opt-in gate
 		if (this.app.workspace.getActiveFile() !== file) return; // only the edited note
 
 		const last = this.lastRenamedAt.get(file.path);
-		if (last && Date.now() - last < COOLDOWN_MS) return; // 10s cooldown
+		if (last && Date.now() - last < COOLDOWN_MS) return; // 6s cooldown
 
 		const existing = this.renameTimers.get(file.path);
 		if (existing) window.clearTimeout(existing);
@@ -78,24 +114,27 @@ export default class ZettelcleanPlugin extends Plugin {
 		);
 	}
 
-	// Compute the target basename, bail if unchanged, otherwise rename.
+	// Compute the target basename via the sticky rule, bail if unchanged, else rename.
 	private async syncNow(file: TFile) {
-		const id = extractTimeId(file.basename);
-		if (id === null) return; // prefix removed meanwhile
-
 		const first = this.app.metadataCache.getFileCache(file)?.headings?.[0];
 		const h1 = first && first.level === 1 ? first.heading : '';
+		const allowDate = this.settings.prefixMode === 'date';
 
-		const newBase = buildFilename(id, generateSlug(h1));
-		if (newBase === file.basename) return; // nothing to do
+		const newBase = computeBasename(file.basename, h1, allowDate);
+		if (newBase === null || newBase === file.basename) return; // unrecognized or no change
 
 		const newPath = this.pathFor(file, newBase);
+		if (this.app.vault.getAbstractFileByPath(newPath)) {
+			new Notice(`Can't rename to "${newBase}.md" - that name already exists`);
+			return; // conflict: keep current name, tell the user
+		}
 		this.isRenameInProgress = true;
 		try {
 			await this.app.fileManager.renameFile(file, newPath);
 			this.lastRenamedAt.set(newPath, Date.now());
 		} catch (e) {
 			console.error('zettelclean: rename failed', e);
+			new Notice('Rename failed (see console)');
 		} finally {
 			this.isRenameInProgress = false;
 		}
@@ -103,10 +142,11 @@ export default class ZettelcleanPlugin extends Plugin {
 
 	private addTimeIdMenu(menu: Menu, file: TAbstractFile) {
 		if (!(file instanceof TFile) || file.extension !== 'md') return;
-		if (extractTimeId(file.basename) !== null) return; // already a zettel
+		const allowDate = this.settings.prefixMode === 'date';
+		if (extractPrefix(file.basename, allowDate) !== null) return; // already a zettel
 		menu.addItem((item) =>
 			item
-				.setTitle('Add zettel TIMEID to filename')
+				.setTitle('Prefix timestamp to filename')
 				.setIcon('clock')
 				.onClick(() => void this.addTimeId(file)),
 		);
@@ -128,4 +168,32 @@ export default class ZettelcleanPlugin extends Plugin {
 		}
 		await this.app.fileManager.renameFile(file, target);
 	}
+
+	// Folder right-click: slug the folder's own name (this folder only, instant).
+	private addFolderSlugMenu(menu: Menu, file: TAbstractFile) {
+		if (!(file instanceof TFolder) || file.isRoot()) return; // never the vault root
+		menu.addItem((item) =>
+			item
+				.setTitle('Slug folder name')
+				.setIcon('folder')
+				.onClick(() => void this.slugFolder(file)),
+		);
+	}
+
+	private async slugFolder(folder: TFolder) {
+		const newName = generateSlug(folder.name);
+		if (!newName || newName === folder.name) {
+			new Notice('Folder name is already clean');
+			return;
+		}
+		const parent = folder.parent;
+		const dir = parent && parent.path !== '/' ? `${parent.path}/` : '';
+		const newPath = `${dir}${newName}`; // folders have no extension
+		if (this.app.vault.getAbstractFileByPath(newPath)) {
+			new Notice(`Cannot rename: "${newName}" already exists`);
+			return;
+		}
+		await this.app.fileManager.renameFile(folder, newPath); // updates [[links]]
+		new Notice(`Renamed folder "${folder.name}" -> "${newName}"`);
+	}
 }

src/settings.ts

@@ -0,0 +1,94 @@
+// *************************************************************************
+// * (C)opyright 2026         by Ruben Carlo Benante                       *
+// *                                                                       *
+// * This program is free software; you can redistribute it and/or modify  *
+// *  it under the terms of the GNU General Public License as published by *
+// *  the Free Software Foundation, either version 3 of the License, or    *
+// *  (at your option) any later version.                                  *
+// *                                                                       *
+// * This program is distributed in the hope that it will be useful,       *
+// *  but WITHOUT ANY WARRANTY; without even the implied warranty of       *
+// *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
+// *  GNU General Public License for more details.                         *
+// *                                                                       *
+// * You should have received a copy of the GNU General Public License     *
+// *  along with this program.  If not, see http://www.gnu.org/licenses/.  *
+// *                                                                       *
+// * Contact author at:                                                    *
+// *  Ruben Carlo Benante                                                  *
+// *  rcb@beco.cc                                                          *
+// *************************************************************************
+
+import { App, PluginSettingTab, Setting, SettingDefinitionItem } from 'obsidian';
+import ZettelcleanPlugin from './main';
+
+export type PrefixMode = 'timeid' | 'date';
+
+export interface ZettelcleanSettings {
+	prefixMode: PrefixMode;
+}
+
+export const DEFAULT_SETTINGS: ZettelcleanSettings = {
+	prefixMode: 'timeid',
+};
+
+const PREFIX_LABELS: Record<string, string> = {
+	timeid: 'Timestamp only (12-18 digits)',
+	date: 'Timestamp and date (yyyy-mm-dd)',
+};
+
+export class ZettelcleanSettingTab extends PluginSettingTab {
+	plugin: ZettelcleanPlugin;
+
+	constructor(app: App, plugin: ZettelcleanPlugin) {
+		super(app, plugin);
+		this.plugin = plugin;
+	}
+
+	// Modern declarative settings (Obsidian 1.13+): the tab renders and indexes
+	// these for settings search. Ignored on older versions, which use display().
+	getSettingDefinitions(): SettingDefinitionItem[] {
+		return [
+			{
+				name: 'Recognized filename prefixes',
+				desc: 'Which leading prefixes mark a note for slug syncing.',
+				control: {
+					type: 'dropdown',
+					key: 'prefixMode',
+					defaultValue: 'timeid',
+					options: PREFIX_LABELS,
+				},
+			},
+		];
+	}
+
+	getControlValue(key: string): unknown {
+		return this.plugin.settings[key as keyof ZettelcleanSettings];
+	}
+
+	async setControlValue(key: string, value: unknown): Promise<void> {
+		this.plugin.settings[key as keyof ZettelcleanSettings] =
+			value as PrefixMode;
+		await this.plugin.saveSettings();
+	}
+
+	// Imperative fallback for Obsidian < 1.13 (e.g. 1.12.x). Not called on 1.13+
+	// once getSettingDefinitions() returns a non-empty array.
+	display(): void {
+		this.containerEl.empty();
+		new Setting(this.containerEl)
+			.setName('Recognized filename prefixes')
+			.setDesc('Which leading prefixes mark a note for slug syncing.')
+			.addDropdown((d) => {
+				for (const [value, label] of Object.entries(PREFIX_LABELS)) {
+					d.addOption(value, label);
+				}
+				d.setValue(this.plugin.settings.prefixMode).onChange(
+					async (value) => {
+						this.plugin.settings.prefixMode = value as PrefixMode;
+						await this.plugin.saveSettings();
+					},
+				);
+			});
+	}
+}

src/slug.test.ts

@@ -21,17 +21,24 @@
 
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
-import { extractTimeId, generateSlug, buildFilename } from './slug.ts';
+import {
+	extractTimeId,
+	extractPrefix,
+	computeBasename,
+	generateSlug,
+	buildFilename,
+} from './slug.ts';
 
-test('slug folds accents, lowercases, collapses', () => {
+test('slug folds accents and collapses, preserving case', () => {
 	assert.equal(
 		generateSlug('Ciências Políticas - Visão Geral'),
-		'ciencias-politicas-visao-geral',
+		'Ciencias-Politicas-Visao-Geral',
 	);
+	assert.equal(generateSlug('Citações'), 'Citacoes');
 });
 
 test('slug collapses runs of punctuation and whitespace to one dash', () => {
-	assert.equal(generateSlug('  Hello,   World!!  '), 'hello-world');
+	assert.equal(generateSlug('  Hello,   World!!  '), 'Hello-World');
 	assert.equal(generateSlug('a/b:c*d?e'), 'a-b-c-d-e');
 });
 
@@ -40,11 +47,13 @@ test('empty or heading-less input yields empty slug', () => {
 	assert.equal(generateSlug('   ---   '), '');
 });
 
-test('extractTimeId accepts 12/14/18-digit prefixes, rejects others', () => {
-	assert.equal(extractTimeId('202607281454-x'), '202607281454'); // 12
+test('extractTimeId accepts 12/14/18-digit prefixes and a non-dash boundary', () => {
+	assert.equal(extractTimeId('202607281454-x'), '202607281454'); // 12, dash
 	assert.equal(extractTimeId('20260728145404-x'), '20260728145404'); // 14
 	assert.equal(extractTimeId('202607281454049999-x'), '202607281454049999'); // 18
 	assert.equal(extractTimeId('20260728145404'), '20260728145404'); // bare id
+	assert.equal(extractTimeId('202607290947 test pkm'), '202607290947'); // space
+	assert.equal(extractTimeId('202607290947test'), '202607290947'); // letters
 	assert.equal(extractTimeId('my-note'), null);
 	assert.equal(extractTimeId('2026-budget'), null); // too short
 	assert.equal(extractTimeId('2026072814540499999-x'), null); // 19, too long
@@ -57,3 +66,31 @@ test('buildFilename collapses empty slug to bare id', () => {
 	);
 	assert.equal(buildFilename('20260728145404', ''), '20260728145404');
 });
+
+test('extractPrefix: timeid always, date only when allowed, dash does not split', () => {
+	assert.equal(extractPrefix('202607302233 vai', false), '202607302233'); // timeid
+	assert.equal(extractPrefix('2026-07-30-Journal', true), '2026-07-30'); // date, dash kept
+	assert.equal(extractPrefix('2026-07-30 Journal', true), '2026-07-30');
+	assert.equal(extractPrefix('2026-07-30 Journal', false), null); // date off
+	assert.equal(extractPrefix('my-note', true), null);
+});
+
+test('computeBasename: sticky tail rule', () => {
+	// H1 sets the tail
+	assert.equal(computeBasename('202607302233', 'Home', false), '202607302233-Home');
+	// delete H1 keeps the last slug (sticky)
+	assert.equal(computeBasename('202607302233-Home', '', false), '202607302233-Home');
+	// no H1: clean the existing tail
+	assert.equal(computeBasename('202607291108 vai', '', false), '202607291108-vai');
+	// punctuation-only H1: keep the existing tail
+	assert.equal(computeBasename('2026-07-30-Home', '!!!', true), '2026-07-30-Home');
+	// bare stays bare
+	assert.equal(computeBasename('202607302233', '', false), '202607302233');
+	// no usable title -> left untouched
+	assert.equal(computeBasename('2026-07-30 !!!', '', true), '2026-07-30 !!!');
+	// date mode gating
+	assert.equal(computeBasename('2026-07-30 Journal', '', true), '2026-07-30-Journal');
+	assert.equal(computeBasename('2026-07-30 Journal', '', false), null);
+	// unrecognized note
+	assert.equal(computeBasename('my-note', 'Title', true), null);
+});

src/slug.ts

@@ -23,9 +23,10 @@
 // in isolation. The transform is always one-way (H1 -> filename), which lets us
 // freely drop characters without worrying about a reverse mapping.
 
-// A TIMEID is a leading run of 12 to 18 digits, ending at a dash or end-of-name.
+// A TIMEID is the leading run of 12 to 18 digits, ending at any non-digit or
+// end-of-name (so "202607290947 test" and "202607290947-slug" both qualify).
 // 12-18 because collision-avoidance may append extra digits to a 14-digit stamp.
-const TIMEID_RE = /^(\d{12,18})(?=-|$)/;
+const TIMEID_RE = /^(\d{12,18})(?=\D|$)/;
 
 // Return the immutable id prefix, or null if this file is not a zettel.
 export function extractTimeId(basename: string): string | null {
@@ -33,13 +34,30 @@ export function extractTimeId(basename: string): string | null {
 	return m?.[1] ?? null;
 }
 
-// H1 text -> kebab slug. sanifize as inspiration, deliberately simpler.
-export function generateSlug(heading: string): string {
-	return heading
+// A date prefix is yyyy-mm-dd, ending at any non-digit or end-of-name. Fixed digit
+// counts with literal dashes, so it captures exactly the date and never breaks at the
+// first dash.
+const DATE_RE = /^(\d{4}-\d{2}-\d{2})(?=\D|$)/;
+
+// The immutable prefix: a TIMEID always; a yyyy-mm-dd date too when allowDate. null if
+// unrecognized. A TIMEID is pure digits and a date has dashes, so the two are disjoint.
+export function extractPrefix(
+	basename: string,
+	allowDate: boolean,
+): string | null {
+	const t = extractTimeId(basename);
+	if (t) return t;
+	if (allowDate) return basename.match(DATE_RE)?.[1] ?? null;
+	return null;
+}
+
+// text (an H1 or a folder name) -> ASCII, case-preserving, dash-separated slug.
+// Shared by the file-rename sync and the folder-slug menu.
+export function generateSlug(text: string): string {
+	return text
 		.normalize('NFKD') // split accented letters into base + combining mark
 		.replace(/[̀-ͯ]/g, '') // strip the combining marks (c-cedilla -> c)
-		.toLowerCase()
-		.replace(/[^a-z0-9]+/g, '-') // any run of non-alphanumerics -> one dash
+		.replace(/[^a-zA-Z0-9]+/g, '-') // non-alphanumerics -> one dash (case kept)
 		.replace(/^-+|-+$/g, ''); // trim leading/trailing dashes
 }
 
@@ -47,3 +65,19 @@ export function generateSlug(heading: string): string {
 export function buildFilename(id: string, slug: string): string {
 	return slug ? `${id}-${slug}` : id;
 }
+
+// Sticky rule. The target basename for a recognized note, or null if it is not a zettel.
+// The tail follows the H1 when that yields a slug; otherwise the existing filename tail is
+// kept and cleaned; a name with no usable title is left untouched (never collapsed to bare).
+export function computeBasename(
+	basename: string,
+	h1: string,
+	allowDate: boolean,
+): string | null {
+	const prefix = extractPrefix(basename, allowDate);
+	if (prefix === null) return null;
+	const rawTail = basename.slice(prefix.length); // generateSlug trims leading separators
+	const tail = generateSlug(h1) || generateSlug(rawTail);
+	if (!tail) return basename; // nothing sluggable (e.g. "2026-07-30 !!!") -> leave untouched
+	return buildFilename(prefix, tail);
+}

versions.json

@@ -1,3 +1,4 @@
 {
-	"0.3.0": "1.0.0"
+	"0.6.0": "1.0.0",
+	"0.6.1": "1.0.0"
 }