Prebid Core : add setScriptAttributes to adloader in Utils (prebid#8624)

* Allow SpotX module to load script without appendChild

* Fix SpotX spec to no longer use appendChild

* Restore spotx files

* Formatting fixes

* Unit test for setScriptAttributes

* Unit test and formatting fix

* Formatting fix

* Comment that attributes are added once only

src/adloader.js

@@ -1,5 +1,5 @@
 import {includes} from './polyfill.js';
-import { logError, logWarn, insertElement } from './utils.js';
+import { logError, logWarn, insertElement, setScriptAttributes } from './utils.js';
 
 const _requestCache = new WeakMap();
 // The below list contains modules or vendors whom Prebid allows to load external JS.
@@ -9,6 +9,7 @@ const _approvedLoadExternalJSList = [
   'criteo',
   'outstream',
   'adagio',
+  'spotx',
   'browsi',
   'brandmetrics',
   'justtag',
@@ -27,8 +28,9 @@ const _approvedLoadExternalJSList = [
  * @param {string} moduleCode bidderCode or module code of the module requesting this resource
  * @param {function} [callback] callback function to be called after the script is loaded
  * @param {Document} [doc] the context document, in which the script will be loaded, defaults to loaded document
+ * @param {object} an object of attributes to be added to the script with setAttribute by [key] and [value]; Only the attributes passed in the first request of a url will be added.
  */
-export function loadExternalScript(url, moduleCode, callback, doc) {
+export function loadExternalScript(url, moduleCode, callback, doc, attributes) {
   if (!moduleCode || !url) {
     logError('cannot load external script without url and moduleCode');
     return;
@@ -77,9 +79,9 @@ export function loadExternalScript(url, moduleCode, callback, doc) {
     } catch (e) {
       logError('Error executing callback', 'adloader.js:loadExternalScript', e);
     }
-  }, doc);
+  }, doc, attributes);
 
-  function requestResource(tagSrc, callback, doc) {
+  function requestResource(tagSrc, callback, doc, attributes) {
     if (!doc) {
       doc = document;
     }
@@ -107,6 +109,10 @@ export function loadExternalScript(url, moduleCode, callback, doc) {
 
     jptScript.src = tagSrc;
 
+    if (attributes) {
+      setScriptAttributes(jptScript, attributes);
+    }
+
     // add the new script tag to the page
     insertElement(jptScript, doc);
 

src/utils.js

@@ -1368,3 +1368,16 @@ export function safeJSONParse(data) {
     return JSON.parse(data);
   } catch (e) {}
 }
+
+/**
+ * Sets dataset attributes on a script
+ * @param {Script} script
+ * @param {object} attributes
+ */
+export function setScriptAttributes(script, attributes) {
+  for (let key in attributes) {
+    if (attributes.hasOwnProperty(key)) {
+      script.setAttribute(key, attributes[key]);
+    }
+  }
+}

test/spec/adloader_spec.js

@@ -69,4 +69,27 @@ describe('adLoader', function () {
       expect(utilsinsertElementStub.callCount).to.equal(2);
     });
   });
+
+  it('attaches passed attributes to a script', function () {
+    const doc = {
+        createElement: function () {
+          return {
+            setAttribute: function (key, value) {
+              this[key] = value;
+            }
+          }
+        },
+        getElementsByTagName: function() {
+          return {
+            firstChild: {
+              insertBefore: function() {}
+            }
+          }
+        }
+      },
+      attrs = {'z': 'A', 'y': 2};
+    let script = adLoader.loadExternalScript('someUrl', 'criteo', undefined, doc, attrs);
+    expect(script.z).to.equal('A');
+    expect(script.y).to.equal(2);
+  });
 });

test/spec/utils_spec.js

@@ -1243,4 +1243,20 @@ describe('Utils', function () {
       });
     });
   });
+
+  describe('setScriptAttributes', () => {
+    it('correctly adds attributes from an object', () => {
+      const script = document.createElement('script'),
+        attrs = {
+          'data-first_prop': '1',
+          'data-second_prop': 'b',
+          'id': 'newId'
+        };
+      script.id = 'oldId';
+      utils.setScriptAttributes(script, attrs);
+      expect(script.dataset['first_prop']).to.equal('1');
+      expect(script.dataset.second_prop).to.equal('b');
+      expect(script.id).to.equal('newId');
+    });
+  });
 });