Add typescript support for helper functions (#598)

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/598
Co-authored-by: konrad <konrad@kola-entertainments.de>
Co-committed-by: konrad <konrad@kola-entertainments.de>

src/modules/listHistory.test.ts

@@ -0,0 +1,67 @@
+import {getHistory, saveListToHistory} from './listHistory'
+
+test('return an empty history when none was saved', () => {
+	Storage.prototype.getItem = jest.fn(() => null)
+	const h = getHistory()
+	expect(h).toStrictEqual([])
+})
+
+test('return a saved history', () => {
+	const saved = [{id: 1}, {id: 2}]
+	Storage.prototype.getItem = jest.fn(() => JSON.stringify(saved))
+
+	const h = getHistory()
+	expect(h).toStrictEqual(saved)
+})
+
+test('store list in history', () => {
+	let saved = {}
+	Storage.prototype.getItem = jest.fn(() => null)
+	Storage.prototype.setItem = jest.fn((key, lists) => {
+		saved = lists
+	})
+
+	saveListToHistory({id: 1})
+	expect(saved).toBe('[{"id":1}]')
+})
+
+test('store only the last 5 lists in history', () => {
+	let saved: string | null = null
+	Storage.prototype.getItem = jest.fn(() => saved)
+	Storage.prototype.setItem = jest.fn((key: string, lists: string) => {
+		saved = lists
+	})
+
+	saveListToHistory({id: 1})
+	saveListToHistory({id: 2})
+	saveListToHistory({id: 3})
+	saveListToHistory({id: 4})
+	saveListToHistory({id: 5})
+	saveListToHistory({id: 6})
+	expect(saved).toBe('[{"id":6},{"id":5},{"id":4},{"id":3},{"id":2}]')
+})
+
+test('don\'t store the same list twice', () => {
+	let saved: string | null = null
+	Storage.prototype.getItem = jest.fn(() => saved)
+	Storage.prototype.setItem = jest.fn((key: string, lists: string) => {
+		saved = lists
+	})
+
+	saveListToHistory({id: 1})
+	saveListToHistory({id: 1})
+	expect(saved).toBe('[{"id":1}]')
+})
+
+test('move a list to the beginning when storing it multiple times', () => {
+	let saved: string | null = null
+	Storage.prototype.getItem = jest.fn(() => saved)
+	Storage.prototype.setItem = jest.fn((key: string, lists: string) => {
+		saved = lists
+	})
+
+	saveListToHistory({id: 1})
+	saveListToHistory({id: 2})
+	saveListToHistory({id: 1})
+	expect(saved).toBe('[{"id":1},{"id":2}]')
+})