Добавил сохранение истории городов между запусками

src/localStorage.js

@@ -0,0 +1,28 @@
+function setToString(set) {
+  let str = "";
+  set.forEach((value) => {
+    str += `${value} `;
+  });
+  return str.trim();
+}
+
+function stringToSet(string) {
+  const set = new Set();
+  string.split(" ").forEach((value) => {
+    set.add(value);
+  });
+  return set;
+}
+
+export function getHistorySet() {
+  let historySet = new Set();
+  const historyString = localStorage.getItem("history");
+  if (historyString !== null && historyString.length > 0) {
+    historySet = stringToSet(historyString);
+  }
+  return historySet;
+}
+
+export function setHistorySet(historySet) {
+  localStorage.setItem("history", setToString(historySet));
+}

src/weatherApp.js

@@ -3,10 +3,11 @@
 // eslint-disable-next-line import/no-self-import
 import oopsImg from "./assets/oops.png";
 import { getInfoByIP, getMap, getWeather } from "./externalRequests";
+import { getHistorySet, setHistorySet } from "./localStorage";
 
 export default async function weatherApp(element) {
   const maxHistorylines = 10;
-  const historyList = new Set();
+  const historySet = new Set();
 
   function showWeather(data) {
     const weatherInfo = element.querySelector("#info");
@@ -41,18 +42,20 @@ export default async function weatherApp(element) {
   }
 
   async function updateHistoryBlock(cityName) {
-    const historyElement = element.querySelector("#history");
-    if (!historyList.has(cityName)) {
-      historyList.add(cityName);
+    if (!historySet.has(cityName)) {
+      const historyElement = element.querySelector("#history");
+      historySet.add(cityName);
       const p = document.createElement("p");
       p.innerHTML = cityName;
       p.addEventListener("click", onclickHistoryLine);
       historyElement.querySelector("span").insertAdjacentElement("afterend", p);
 
       if (historyElement.querySelectorAll("p").length > maxHistorylines) {
-        historyList.delete(historyElement.lastElementChild.innerHTML);
+        historySet.delete(historyElement.lastElementChild.innerHTML);
         historyElement.removeChild(historyElement.lastElementChild);
       }
+
+      setHistorySet(historySet);
     }
   }
 
@@ -75,7 +78,9 @@ export default async function weatherApp(element) {
   <div id="history" class="history-block">
     <span>History:</span>
   </div>`;
-
+  if (getHistorySet().size > 0) {
+    getHistorySet().forEach((cityName) => updateHistoryBlock(cityName));
+  }
   if (ipInfo.region) updateWeather(ipInfo.region);
 
   element

src/weatherApp.test.js

@@ -44,6 +44,7 @@ describe("Weather application tests", () => {
   }
 
   beforeEach(() => {
+    localStorage.clear();
     // Моки
     exteranlApi.getWeather.mockReturnValue(weather.Moscow);
     exteranlApi.getInfoByIP.mockReturnValue(ipInfo);
@@ -153,7 +154,7 @@ describe("Weather application tests", () => {
     );
   });
 
-  it("History block have only one distinct city names", async () => {
+  it("History block have only distinct city names", async () => {
     for (let i = 0; i < 5; i += 1) {
       specifyCityName(`DefaultCity`);
       submit();
@@ -164,4 +165,16 @@ describe("Weather application tests", () => {
 
     expect(getAllHistoryParagraphs()).toStrictEqual(["DefaultCity"]);
   });
+
+  it("History loads from localStorage", async () => {
+    specifyCityName(`Moscow`);
+    submit();
+
+    weatherApp(el);
+
+    // Надо подождать, когда все асинк функции закончатся, а потом продолжать выполнять синхронный код
+    await new Promise(process.nextTick);
+
+    expect(getAllHistoryParagraphs()).toStrictEqual(["Moscow"]);
+  });
 });