fix(SPA): save article list pagination in query url

web/src/lib/__tests__/pageSizeMemory.spec.ts

@@ -0,0 +1,55 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { readStoredPageSize, storePageSize } from '../pageSizeMemory'
+
+const KEY = 'renewcms-page-size-articles'
+const SIZES = [5, 25, 50, 100]
+
+describe('pageSizeMemory', () => {
+	beforeEach(() => {
+		localStorage.clear()
+	})
+
+	afterEach(() => {
+		vi.unstubAllGlobals()
+		vi.restoreAllMocks()
+	})
+
+	it('reads null when nothing is stored', () => {
+		expect(readStoredPageSize(KEY, SIZES)).toBeNull()
+	})
+
+	it.each(['5', '25', '50', '100'])('reads the valid stored size %s', (raw) => {
+		localStorage.setItem(KEY, raw)
+		expect(readStoredPageSize(KEY, SIZES)).toBe(Number(raw))
+	})
+
+	it.each(['10', 'abc', '0', '-5', '25.5', '', '5.0', ' 5'])('treats %j as absent', (raw) => {
+		localStorage.setItem(KEY, raw)
+		expect(readStoredPageSize(KEY, SIZES)).toBeNull()
+	})
+
+	it('stores the bare number', () => {
+		storePageSize(KEY, 50)
+		expect(localStorage.getItem(KEY)).toBe('50')
+	})
+
+	it('reads as absent when getItem throws', () => {
+		vi.spyOn(Storage.prototype, 'getItem').mockImplementation(() => {
+			throw new Error('denied')
+		})
+		expect(readStoredPageSize(KEY, SIZES)).toBeNull()
+	})
+
+	it('swallows a setItem that throws', () => {
+		vi.spyOn(Storage.prototype, 'setItem').mockImplementation(() => {
+			throw new Error('quota')
+		})
+		expect(() => storePageSize(KEY, 50)).not.toThrow()
+	})
+
+	it('copes with localStorage being undefined', () => {
+		vi.stubGlobal('localStorage', undefined)
+		expect(readStoredPageSize(KEY, SIZES)).toBeNull()
+		expect(() => storePageSize(KEY, 50)).not.toThrow()
+	})
+})

web/src/lib/pageSizeMemory.ts

@@ -0,0 +1,18 @@
+export const ARTICLES_PAGE_SIZE_KEY = 'renewcms-page-size-articles'
+
+export function readStoredPageSize(key: string, validSizes: number[]) {
+	try {
+		const raw = localStorage.getItem(key)
+		return validSizes.find((size) => String(size) === raw) ?? null
+	} catch {
+		return null
+	}
+}
+
+export function storePageSize(key: string, size: number) {
+	try {
+		localStorage.setItem(key, String(size))
+	} catch {
+		return
+	}
+}