chore: add unit tests

Author: hakenprog

src/runtime/plugin.ts

@@ -43,6 +43,7 @@ export default defineNuxtPlugin((nuxtApp) => {
     // Exit if the last entry is the same as the new entry
     if (isRepeatedEntry(data, sessionId)) return;
 
+    // Add the new item to the data array
     data.value.unshift(dataObject);
     localStorage.setItem(LOCAL_STORAGE_KEY, JSON.stringify(data.value));
   });

src/runtime/utm.ts

@@ -11,7 +11,7 @@ export const readLocalData = (localStorageKey: string) => {
 
   try {
     if (localData) {
-      return JSON.parse(localData);
+      return JSON.parse(localData) as DataObject[];
     }
   } catch (error) {
     console.error("Error parsing local storage data", error);
@@ -29,29 +29,28 @@ export const getSessionID = (sessionIdKey: string) => {
   return sessionID;
 };
 
-export const urlHasUtmParams = (query: LocationQuery) => {
-  return (
+export const urlHasUtmParams = (query: LocationQuery): boolean => {
+  return Boolean(
     query.utm_source ||
-    query.utm_medium ||
-    query.utm_campaign ||
-    query.utm_term ||
-    query.utm_content
+      query.utm_medium ||
+      query.utm_campaign ||
+      query.utm_term ||
+      query.utm_content
   );
 };
 
-export const getUtmParams = (query: LocationQuery) => {
-  const utmParams: UTMParams = {
+export const getUtmParams = (query: LocationQuery): UTMParams => {
+  return {
     utm_source: query.utm_source?.toString(),
     utm_medium: query.utm_medium?.toString(),
     utm_campaign: query.utm_campaign?.toString(),
     utm_term: query.utm_term?.toString(),
     utm_content: query.utm_content?.toString(),
   };
-  return utmParams;
 };
 
-export const getAdditionalInfo = () => {
-  const additionalInfo: AdditionalInfo = {
+export const getAdditionalInfo = (): AdditionalInfo => {
+  return {
     referrer: document.referrer,
     userAgent: navigator.userAgent,
     language: navigator.language,
@@ -60,13 +59,12 @@ export const getAdditionalInfo = () => {
       height: screen.height,
     },
   };
-  return additionalInfo;
 };
 
 export const isRepeatedEntry = (
   data: Ref<DataObject[]>,
   currentSessionID: string
-) => {
+): boolean => {
   const lastEntry = data.value?.[0];
   return lastEntry && lastEntry.sessionId === currentSessionID;
 };

test/unit.test.ts

@@ -0,0 +1,110 @@
+import { ref, Ref } from "vue";
+import { DataObject } from "nuxt-utm";
+import {
+  isRepeatedEntry,
+  readLocalData,
+  urlHasUtmParams,
+  getUtmParams,
+} from "./../src/runtime/utm";
+import { describe, it, expect, beforeEach } from "vitest";
+
+global.localStorage = (() => {
+  let store: Record<string, string> = {};
+
+  return {
+    getItem: (key: string): string => store[key] ?? null,
+    setItem: (key: string, value: string): void => {
+      store[key] = value.toString();
+    },
+    removeItem: (key: string): void => {
+      delete store[key];
+    },
+    clear: (): void => {
+      store = {};
+    },
+    key: (index: number): string | null => "",
+    length: Object.keys(store).length,
+  };
+})();
+
+describe("readLocalData function", () => {
+  beforeEach(() => {
+    localStorage.clear();
+  });
+  it("Returns empty array if local storage is empty", () => {
+    expect(readLocalData("nuxt-utm-test")).toEqual([]);
+  });
+
+  it("Returns an array with objects if local storage has data", () => {
+    localStorage.setItem("nuxt-utm-test", utmItem);
+    expect(readLocalData("nuxt-utm-test")).toEqual(JSON.parse(utmItem));
+  });
+});
+
+describe("urlHasUtmParams function", () => {
+  it("Returns false if there are no utm values", () => {
+    const locationQueryMock = {};
+    expect(urlHasUtmParams(locationQueryMock)).toBeFalsy();
+  });
+
+  it("Returns true if at least one utm value exists", () => {
+    const locationQueryMock = { utm_source: "test_source" };
+    expect(urlHasUtmParams(locationQueryMock)).toBeTruthy();
+  });
+});
+
+describe("getUtmParams function", () => {
+  it("Returns the correct utm values", () => {
+    const locationQueryMock = {
+      utm_source: "test_source",
+      utm_medium: "test_medium",
+      utm_term: "test_term",
+      utm_content: "test_content",
+    };
+    expect(getUtmParams(locationQueryMock)).toEqual({
+      utm_source: "test_source",
+      utm_medium: "test_medium",
+      utm_term: "test_term",
+      utm_content: "test_content",
+    });
+  });
+});
+
+describe("isRepeatedEntry function", () => {
+  let data: Ref<DataObject[]>;
+  beforeEach(() => {
+    data = ref<DataObject[]>(JSON.parse(`[${utmItem}]`));
+  });
+
+  it("Returns true if the utm params and the session already exists in local storage", () => {
+    expect(isRepeatedEntry(data, "beai1gx7dg")).toBeTruthy();
+  });
+  it("Returns false if the utm params are the same but the session is different", () => {
+    expect(isRepeatedEntry(data, "newSession")).toBeFalsy();
+  });
+  it("Returns false if the utm params are different but the session is the same", () => {
+    const data = ref<DataObject[]>(JSON.parse(`[${utmItem}]`));
+    expect(isRepeatedEntry(data, "newSession")).toBeFalsy();
+  });
+});
+
+const utmItem = `{
+  "timestamp": "2023-11-02T10:11:17.219Z",
+  "utmParams": {
+    "utm_source": "test_source",
+    "utm_medium": "test_medium",
+    "utm_campaign": "test_campaign",
+    "utm_term": "test_term",
+    "utm_content": "test_content"
+  },
+  "additionalInfo": {
+    "referrer": "http://localhost:3000/?utm_source=test_source&utm_medium=test_medium&utm_campaign=test_campaign&utm_term=test_term&utm_content=test_content",
+    "userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36",
+    "language": "en-GB",
+    "screen": {
+      "width": 1728,
+      "height": 1117
+    }
+  },
+  "sessionId": "beai1gx7dg"
+}`;