Improve google-ima3

Do not overwrite google.ima if it was already set

CHANGELOG.md

@@ -18,6 +18,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- issue with overwriting `google.ima` value if it was already set
+  [#331](https://github.com/AdguardTeam/Scriptlets/issues/331)
 - issue with printing unnecessary logs to the console in `log-addEventListener` scriptlet
   [#335](https://github.com/AdguardTeam/Scriptlets/issues/335)
 - error throwing in `prevent-fetch` and `prevent-xhr` scriptlets when a request is blocked

src/redirects/google-ima3.js

@@ -26,8 +26,9 @@ import {
 export function GoogleIma3(source) {
     const VERSION = '3.453.0';
 
-    const ima = {};
-
+    // Do not overwrite window.google.ima if it was already set
+    // https://github.com/AdguardTeam/Scriptlets/issues/331
+    const ima = typeof window.google?.ima === 'object' ? window.google.ima : {};
     const AdDisplayContainer = function () { };
     AdDisplayContainer.prototype.destroy = noopFunc;
     AdDisplayContainer.prototype.initialize = noopFunc;

tests/redirects/google-ima3.test.js

@@ -87,3 +87,36 @@ test('Ima - run requestAds function twice', (assert) => {
         done();
     });
 });
+
+test('Ima - check if google.ima.dai was NOT overwritten', (assert) => {
+    // Test for https://github.com/AdguardTeam/Scriptlets/issues/331
+    const done = assert.async();
+
+    window.google = {
+        ima: {
+            dai: {
+                api: {
+                    StreamManager() { },
+                },
+            },
+        },
+    };
+
+    runRedirect(name);
+
+    let number = 0;
+    const test = () => {
+        number += 1;
+    };
+    const { ima } = window.google;
+    const AdsLoader = new ima.AdsLoader();
+    AdsLoader.addEventListener(ima.AdsManagerLoadedEvent.Type.ADS_MANAGER_LOADED, test);
+
+    assert.ok(typeof window.google.ima.dai.api.StreamManager === 'function',
+        'window.google.ima.dai.api.StreamManager was not overwritten');
+    AdsLoader.requestAds();
+    requestAnimationFrame(() => {
+        assert.strictEqual(number, 1, 'number is equal to 1');
+        done();
+    });
+});