client_v2: add ESLint + wire lint/format/typecheck into lefthook

client_v2 has matured, so enforce its checks like the old client:

- Add ESLint (typescript-eslint + eslint-plugin-svelte) with a flat
  config; `lint` now runs prettier --check and eslint.
- Add a "Client v2" group to lefthook pre-commit and ci: eslint,
  prettier, and svelte-check type checking (svelte-kit sync first).
- Exclude generated paraglide output from prettier.

Fix the linting warnings this surfaced: drop dead vars and an unused
svelte-ignore, mark intentional reactive reads with `void`, remove a
useless children snippet, and clean up useless string-literal mustaches.

Disable svelte/no-navigation-without-resolve (base-path resolution is
centralized in params.ts helpers, so the rule only false-positives and
wrapping call sites would double-apply the base path). Keep
svelte/prefer-svelte-reactivity on with per-line disables at the
transient-local Set/Map sites.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client_v2/.prettierignore

@@ -6,3 +6,6 @@ build
 .svelte-kit
 dist
 node_modules
+
+# Generated code (paraglide i18n compiler output — also gitignored)
+src/lib/paraglide

client_v2/README.md

@@ -82,7 +82,7 @@ Everything viewed is subscribed to and live-updates. The seam is `api/live.ts`
 - **`inventory`** is a reactive normalized **cache**. `api/liveSync.ts` runs one
   central subscription per resource and applies remote events to it, so every
   cache-backed view (inspectors, locations) is live automatically.
-- The **paginated list** fetches server-paged data *outside* the cache, so it
+- The **paginated list** fetches server-paged data _outside_ the cache, so it
   keeps its **own** subscription and refetches the current page on relevant
   events.
 - Local edits patch the cache **and** emit a `local` event (mirroring the server
@@ -101,7 +101,7 @@ CSS custom properties in `src/app.css`.
 - **Desktop** — two panes: the filament/spool list on the left, a live inspector
   on the right.
 - **Mobile** — the list becomes full-width and front-and-centre; selecting an item
-  slides the *same* inspector up as a bottom-sheet **Drawer**
+  slides the _same_ inspector up as a bottom-sheet **Drawer**
   (`src/lib/components/Drawer.svelte`). The top-bar search/nav reflow onto their
   own rows and the "Add spools" button becomes a FAB.
 

client_v2/eslint.config.js

@@ -0,0 +1,55 @@
+import js from '@eslint/js';
+import svelte from 'eslint-plugin-svelte';
+import prettier from 'eslint-config-prettier';
+import globals from 'globals';
+import ts from 'typescript-eslint';
+import svelteConfig from './svelte.config.js';
+
+export default ts.config(
+	// Generated, tooling-managed, and build-output directories are not linted.
+	{
+		ignores: [
+			'build/',
+			'.svelte-kit/',
+			'dist/',
+			'package/',
+			'src/lib/paraglide/', // auto-generated by inlang paraglide-js
+			'project.inlang/', // inlang-managed
+			'locales/' // Weblate-managed translation files
+		]
+	},
+	js.configs.recommended,
+	...ts.configs.recommended,
+	...svelte.configs.recommended,
+	prettier,
+	...svelte.configs.prettier,
+	{
+		languageOptions: {
+			globals: { ...globals.browser, ...globals.node }
+		},
+		rules: {
+			// Typed as `no-undef`; TypeScript already reports undefined identifiers.
+			'no-undef': 'off',
+			// Base-path resolution is centralized in src/lib/library/params.ts helpers
+			// (selectHref/libraryHref/etc. already call resolve() from $app/paths), and
+			// generic components take a pre-resolved href prop. This rule can't see through
+			// those helpers, so it only produces false positives here — and blindly wrapping
+			// call sites in resolve() would double-apply the deploy base path.
+			'svelte/no-navigation-without-resolve': 'off'
+			// svelte/prefer-svelte-reactivity is left ON to guard against in-place mutation of
+			// reactive Set/Map. The current hits are all transient computation-local collections
+			// and are silenced with per-line eslint-disable comments at each site.
+		}
+	},
+	{
+		files: ['**/*.svelte', '**/*.svelte.ts', '**/*.svelte.js'],
+		languageOptions: {
+			parserOptions: {
+				projectService: true,
+				extraFileExtensions: ['.svelte'],
+				parser: ts.parser,
+				svelteConfig
+			}
+		}
+	}
+);

client_v2/package.json

@@ -13,19 +13,26 @@
 		"check": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json",
 		"check:watch": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json --watch",
 		"format": "prettier --write .",
-		"lint": "prettier --check ."
+		"lint": "prettier --check . && eslint .",
+		"lint:eslint": "eslint ."
 	},
 	"devDependencies": {
+		"@eslint/js": "^9.39.5",
 		"@inlang/paraglide-js": "^2.18.2",
 		"@sveltejs/adapter-static": "^3.0.6",
 		"@sveltejs/kit": "^2.8.1",
 		"@sveltejs/vite-plugin-svelte": "^4.0.0",
 		"@types/qrcode": "^1.5.6",
+		"eslint": "^9.39.5",
+		"eslint-config-prettier": "^10.1.8",
+		"eslint-plugin-svelte": "^3.22.0",
+		"globals": "^16.5.0",
 		"prettier": "^3.3.3",
 		"prettier-plugin-svelte": "^3.2.7",
 		"svelte": "^5.1.9",
 		"svelte-check": "^4.0.5",
 		"typescript": "^5.6.3",
+		"typescript-eslint": "^8.65.0",
 		"vite": "^5.4.10"
 	},
 	"dependencies": {

client_v2/project.inlang/settings.json

@@ -37,4 +37,4 @@
 		"lt",
 		"tr"
 	]
-}
+}

client_v2/src/lib/components/AddSpoolModal.svelte

@@ -162,6 +162,7 @@
 			]).then(([vn, localMats, extMats]) => {
 				vendorNames = vn;
 				const specs: typeof materialSpecs = {};
+				// eslint-disable-next-line svelte/prefer-svelte-reactivity -- transient local, not reactive state
 				const names = new Set<string>(localMats);
 				// Seed with the built-in common materials first…
 				for (const m of COMMON_MATERIALS) {
@@ -388,9 +389,6 @@
 		}
 	}
 
-	let targetName = $derived(
-		creating ? nf.name.trim() || m['add.newFilament']() : chosen ? cName(chosen) : ''
-	);
 	let summary = $derived(chosen || creating ? m['add.summary']({ count: countN }) : '');
 
 	// --- validation ---------------------------------------------------------
@@ -520,11 +518,11 @@
 							{#each externalResults as ext (ext.id)}
 								<button class="res-item" onclick={() => choose({ source: 'external', ext })}>
 									<Swatch
-									colors={externalColors(ext)}
-									direction={externalDirection(ext)}
-									size={18}
-									radius={5}
-								/>
+										colors={externalColors(ext)}
+										direction={externalDirection(ext)}
+										size={18}
+										radius={5}
+									/>
 									<div class="res-name">
 										<span class="rn">{ext.name}</span>
 										<span class="rs">{ext.manufacturer} · {ext.material}</span>

client_v2/src/lib/components/EditableField.svelte

@@ -9,13 +9,7 @@
 	let { value, placeholder = '—', mono = false, oninput }: Props = $props();
 </script>
 
-<input
-	class="edit"
-	class:mono
-	{value}
-	{placeholder}
-	oninput={(e) => oninput?.(e.currentTarget.value)}
-/>
+<input class="edit" class:mono {value} {placeholder} oninput={(e) => oninput?.(e.currentTarget.value)} />
 
 <style>
 	.edit {

client_v2/src/lib/components/Pagination.svelte

@@ -58,7 +58,11 @@
 	{#if pageCount > 1}
 		<div class="nums">
 			{#if hrefFor && page > 1}
-				<a class="pg nav" href={hrefFor(page - 1)} data-sveltekit-keepfocus data-sveltekit-noscroll
+				<a
+					class="pg nav"
+					href={hrefFor(page - 1)}
+					data-sveltekit-keepfocus
+					data-sveltekit-noscroll
 					aria-label={m['pagination.prev']()}><ChevronLeft size={16} /></a
 				>
 			{:else}
@@ -79,7 +83,11 @@
 				{/if}
 			{/each}
 			{#if hrefFor && page < pageCount}
-				<a class="pg nav" href={hrefFor(page + 1)} data-sveltekit-keepfocus data-sveltekit-noscroll
+				<a
+					class="pg nav"
+					href={hrefFor(page + 1)}
+					data-sveltekit-keepfocus
+					data-sveltekit-noscroll
 					aria-label={m['pagination.next']()}><ChevronRight size={16} /></a
 				>
 			{:else}

client_v2/src/lib/components/QrScannerModal.svelte

@@ -137,7 +137,6 @@
 			<p class="hint">{m['scanner.description']()}</p>
 
 			<div class="stage">
-				<!-- svelte-ignore a11y_media_has_caption -->
 				<video bind:this={video} playsinline></video>
 				{#if error}
 					<div class="msg error">{error}</div>

client_v2/src/lib/components/labels/PrintLayoutPanel.svelte

@@ -84,6 +84,7 @@
 	});
 	async function loadInitial(signal: AbortSignal) {
 		try {
+			// eslint-disable-next-line svelte/prefer-svelte-reactivity -- transient local, not reactive state
 			const seen = new Set<number>();
 			const ids: number[] = [];
 			let offset = 0;
@@ -149,6 +150,7 @@
 	async function runSearch(q: string, signal: AbortSignal) {
 		try {
 			const { spools, filaments } = await searchAll(q, COLOR_THRESHOLD, signal);
+			// eslint-disable-next-line svelte/prefer-svelte-reactivity -- transient local, not reactive state
 			const ids = new Set<number>(spools.map((m) => m.entity.id));
 			// The /search spool pass only matches spool-native fields, so also pull
 			// the spools of any matched filament — that's how a filament- or
@@ -196,6 +198,7 @@
 	const recentCount = $derived(visibleSpools.filter(isRecent).length);
 
 	function toggle(id: number) {
+		// eslint-disable-next-line svelte/prefer-svelte-reactivity -- transient local; `selected` updates via reassignment below
 		const next = new Set(selected);
 		if (next.has(id)) next.delete(id);
 		else next.add(id);
@@ -258,6 +261,7 @@
 	});
 
 	function toggleF(id: string) {
+		// eslint-disable-next-line svelte/prefer-svelte-reactivity -- transient local; `selectedF` updates via reassignment below
 		const next = new Set(selectedF);
 		if (next.has(id)) next.delete(id);
 		else next.add(id);

client_v2/src/lib/components/library/FilamentInspector.svelte

@@ -49,7 +49,7 @@
 	$effect(() => {
 		const id = filamentId;
 		const archived = showArchived;
-		revision; // refetch on live spool events
+		void revision; // refetch on live spool events
 		let cancelled = false;
 		spoolSource
 			.listSpools({
@@ -121,9 +121,7 @@
 	</div>
 
 	<SectionLabel>
-		{#snippet children()}<span style="padding-left:20px"
-				>{m['inspector.spoolsCount']({ count: spools.length })}</span
-			>{/snippet}
+		<span style="padding-left:20px">{m['inspector.spoolsCount']({ count: spools.length })}</span>
 		{#snippet right()}
 			<button
 				class="arch-toggle"

client_v2/src/lib/components/library/FilamentList.svelte

@@ -47,7 +47,7 @@
 		const ctrl = new AbortController();
 		const gq = isGrouped ? buildGroupQuery(libraryState, ctrl.signal) : null;
 		const sq = isGrouped ? null : buildFlatSpoolQuery(libraryState, ctrl.signal);
-		revision; // refetch on live events
+		void revision; // refetch on live events
 		const mine = ++reqId;
 		loading = true;
 		errored = false;

client_v2/src/lib/components/library/GroupRow.svelte

@@ -49,7 +49,7 @@
 	let reqId = 0;
 	$effect(() => {
 		const ctrl = new AbortController();
-		revision; // refetch on live events
+		void revision; // refetch on live events
 		const want = untrack(() => spools.length) || PAGE;
 		const q = buildScopedSpoolQuery(libraryState, group, want, 0, ctrl.signal);
 		const mine = ++reqId;

client_v2/src/lib/components/library/SearchBox.svelte

@@ -160,16 +160,6 @@
 
 	// "matched: <field>" label. Extra fields resolve to the field's display name;
 	// native fields get a translated label (falling back to the raw name).
-	const NATIVE_MATCH = new Set([
-		'name',
-		'material',
-		'article_number',
-		'comment',
-		'location',
-		'lot_nr',
-		'id',
-		'color'
-	]);
 	const MATCH_LABEL: Record<EntityKind, Record<string, () => string>> = {
 		filament: {
 			name: m['filament.fields.name'],
@@ -257,11 +247,7 @@
 							onclick={onResultClick}
 						>
 							<span class="id mono">#{spool.entity.id}</span>
-							<Swatch
-							colors={filament?.colors ?? []}
-							direction={filament?.multiColorDirection}
-							size={20}
-						/>
+							<Swatch colors={filament?.colors ?? []} direction={filament?.multiColorDirection} size={20} />
 							<span class="text">
 								<span class="title">{filament?.name || m['search.unknownFilament']()}</span>
 								{#if spool.entity.location}<span class="sub">{spool.entity.location}</span>{/if}
@@ -308,12 +294,7 @@
 						<a
 							class="result"
 							class:active={activeIndex === indexOf('vendor', vendor.entity.id)}
-							href={searchResultHref(
-								page.url.searchParams,
-								page.url.pathname,
-								'vendor',
-								vendor.entity.id
-							)}
+							href={searchResultHref(page.url.searchParams, page.url.pathname, 'vendor', vendor.entity.id)}
 							data-sveltekit-noscroll
 							onclick={onResultClick}
 						>

client_v2/src/lib/stores/fields.svelte.ts

@@ -1,4 +1,11 @@
-import { getFields, setField, deleteField, type EntityType, type FieldDef, type FieldParams } from '$lib/api/fields';
+import {
+	getFields,
+	setField,
+	deleteField,
+	type EntityType,
+	type FieldDef,
+	type FieldParams
+} from '$lib/api/fields';
 
 // Reactive cache of extra-field definitions per entity type. Loaded on demand
 // (inspectors) and by the settings manager; refetched after mutations.

client_v2/src/lib/utils/color.ts

@@ -28,8 +28,7 @@ export function hexRgb(h: string): [number, number, number] {
 export function swatchStyle(colors: string[] | undefined, direction?: MultiColorDirection): string {
 	if (!colors || !colors.length) return 'background:#555';
 	if (colors.length > 1) {
-		const angle =
-			direction === 'coaxial' ? '90deg' : direction === 'longitudinal' ? '0deg' : '135deg';
+		const angle = direction === 'coaxial' ? '90deg' : direction === 'longitudinal' ? '0deg' : '135deg';
 		// Each colour gets its own band, but boundaries are softened by a narrow
 		// feather rather than a hard edge or a full-slot blur: colour i stays solid
 		// across most of [i*step, (i+1)*step] and only fades over `feather`% on each

client_v2/src/routes/+layout.ts

@@ -1,5 +1,3 @@
-import { browser } from '$app/environment';
-
 // Spoolman ships as a client-side SPA served from the backend, so disable SSR
 // and prerender the shell.
 export const ssr = false;

client_v2/src/routes/locations/+page.svelte

@@ -129,6 +129,7 @@
 			});
 			// A NULL location and an empty-string one are distinct rows to the database
 			// but the same "No location" card here, so counts are summed by key.
+			// eslint-disable-next-line svelte/prefer-svelte-reactivity -- transient local, not reactive state
 			const totals = new Map<string, number>();
 			for (const g of page.items) totals.set(g.key, (totals.get(g.key) ?? 0) + g.spoolCount);
 
@@ -360,6 +361,7 @@
 
 	// Which locations currently hold spools, by display name.
 	function presentNames(): Set<string> {
+		// eslint-disable-next-line svelte/prefer-svelte-reactivity -- transient local, not reactive state
 		const names = new Set<string>();
 		for (const [key, b] of Object.entries(buckets)) {
 			if (b.total > 0) names.add(key === EMPTY ? NO_LOCATION : key);
@@ -666,12 +668,14 @@
 								<div class="chip-info">
 									<div class="chip-title">
 										<span class="chip-id mono">#{s.id}</span>
-										{#if v.name !== '?'}{v.name}{' - '}{/if}{f.name}
+										{#if v.name !== '?'}{v.name} -
+										{/if}{f.name}
 									</div>
 									<div class="chip-subtitle">
-										{f.material}{' - '}<span class:low={settings.isLow(s.remaining, s.unused)}
-											>{weightAuto(s.remaining)}</span
-										>{' / '}{weightAuto(f.weight)}{#if s.lastUsedLabel}{' - '}{m['locations.lastUsed']({
+										{f.material} -
+										<span class:low={settings.isLow(s.remaining, s.unused)}>{weightAuto(s.remaining)}</span>
+										/ {weightAuto(f.weight)}{#if s.lastUsedLabel}
+											- {m['locations.lastUsed']({
 												time: s.lastUsedLabel
 											})}{/if}
 									</div>

client_v2/vite.config.ts

@@ -8,7 +8,7 @@ export default defineConfig({
 		paraglideVitePlugin({
 			project: './project.inlang',
 			outdir: './src/lib/paraglide',
-			strategy: ["localStorage", "preferredLanguage", "baseLocale"]
+			strategy: ['localStorage', 'preferredLanguage', 'baseLocale']
 		})
 	],
 	server: { port: 5174 }

lefthook.yml

@@ -23,6 +23,21 @@ pre-commit:
             root: "client/"
             run: ./node_modules/.bin/prettier --write .
             stage_fixed: true
+    - group: # Client v2 checks
+        parallel: false
+        jobs:
+          - name: Run lint check on client_v2 files
+            root: "client_v2/"
+            run: ./node_modules/.bin/eslint --fix . # Hardcoded path because Windows messes up if we use npx
+            stage_fixed: true
+          - name: Run format check on client_v2 files
+            root: "client_v2/"
+            run: ./node_modules/.bin/prettier --write .
+            stage_fixed: true
+          - name: Run type check on client_v2 files
+            root: "client_v2/"
+            # svelte-kit sync generates .svelte-kit/tsconfig.json, which svelte-check needs.
+            run: ./node_modules/.bin/svelte-kit sync && ./node_modules/.bin/svelte-check --tsconfig ./tsconfig.json
 
 # Same as pre-commit but no fixes
 ci:
@@ -46,4 +61,17 @@ ci:
           - name: Run format check on client files
             root: "client/"
             run: ./node_modules/.bin/prettier --check .
+    - group: # Client v2 checks
+        parallel: false
+        jobs:
+          - name: Run lint check on client_v2 files
+            root: "client_v2/"
+            run: ./node_modules/.bin/eslint . # Hardcoded path because Windows messes up if we use npx
+          - name: Run format check on client_v2 files
+            root: "client_v2/"
+            run: ./node_modules/.bin/prettier --check .
+          - name: Run type check on client_v2 files
+            root: "client_v2/"
+            # svelte-kit sync generates .svelte-kit/tsconfig.json, which svelte-check needs.
+            run: ./node_modules/.bin/svelte-kit sync && ./node_modules/.bin/svelte-check --tsconfig ./tsconfig.json