Add custom functions to create close cookies

Calling `mw.centralNotice.hideBanner()` causes a spike in false
tracking events during the fundraising campaign, due to the
function looping the multiple URLS contained in `wgNoticeHideUrls`
in order to set cookies on multiple wikis.

This replaces the `hideBanner` call with custom setters that only
create the cookies on wikipedia.org.

See https://phabricator.wikimedia.org/T344381

src/page/MediaWiki/WindowMediaWiki.ts

@@ -2,6 +2,8 @@ import { MediaWiki } from '@src/page/MediaWiki/MediaWiki';
 import { LegacyBannerEvent } from '@src/page/MediaWiki/LegacyBannerEvent';
 import { SizeIssue } from '@src/page/MediaWiki/SizeIssue';
 import { BannerEvent } from '@src/page/MediaWiki/BannerEvent';
+import { setCookie } from '@src/page/MediaWiki/setCookie';
+import { createImageCookieSetter } from '@src/page/MediaWiki/createImageCookieSetter';
 
 interface MediaWikiTools {
 	config: { get: ( item: string ) => any };
@@ -52,16 +54,21 @@ export class WindowMediaWiki implements MediaWiki {
 	}
 
 	public preventBannerDisplayForPeriod(): void {
-		window.mw.centralNotice.hideBanner();
+		this.hideBanner( 'close', this.getConfigItem( 'wgNoticeCookieDurations' ).close );
 	}
 
 	public preventBannerDisplayUntilEndOfCampaign(): void {
 		const endOfYear = new Date( new Date().getFullYear(), 11, 31, 23, 59, 59 );
 		const secondsToEndOfYear = Math.abs( ( endOfYear.getTime() - Date.now() ) / 1000 );
-		window.mw.centralNotice.customHideBanner( 'donate', secondsToEndOfYear );
+		this.hideBanner( 'donate', secondsToEndOfYear );
 	}
 
 	public setBannerLoadedButHidden(): void {
 		window.mw.centralNotice.setBannerLoadedButHidden();
 	}
+
+	private hideBanner( reason: string, durationInSeconds: number ): void {
+		setCookie( reason, new Date(), durationInSeconds );
+		createImageCookieSetter( reason, durationInSeconds, this.getConfigItem( 'wgNoticeHideUrls' )[ 0 ] );
+	}
 }

src/page/MediaWiki/createImageCookieSetter.ts

@@ -0,0 +1,19 @@
+const HIDE_EVENT_TRACKING_CATEGORY = 'fundraising';
+
+export function createImageCookieSetter( reason: string, durationInSeconds: number, trackingUrl: string ): void {
+	const trackingData = {
+		duration: String( durationInSeconds ),
+		category: HIDE_EVENT_TRACKING_CATEGORY,
+		reason: reason
+	};
+
+	const baseUrl = new URL( 'https:' + trackingUrl );
+	const newParams = new URLSearchParams( [
+		...Array.from( baseUrl.searchParams.entries() ),
+		...Object.entries( trackingData )
+	] ).toString();
+
+	const trackingImgUrl = new URL( `${ baseUrl.origin }${ baseUrl.pathname }?${ newParams }` );
+
+	document.createElement( 'img' ).src = trackingImgUrl.toString();
+}

src/page/MediaWiki/setCookie.ts

@@ -0,0 +1,14 @@
+const COOKIE_NAME = 'centralnotice_hide_fundraising';
+
+export function setCookie( reason: string, created: Date, durationInSeconds: number ): void {
+	const expiryDate = new Date( created.getTime() );
+	expiryDate.setSeconds( created.getSeconds() + durationInSeconds );
+
+	const hideData = {
+		v: 1,
+		created: Math.floor( created.getTime() / 1000 ),
+		reason: reason
+	};
+
+	document.cookie = `${ COOKIE_NAME }=${ encodeURIComponent( JSON.stringify( hideData ) ) }; expires=${ expiryDate.toUTCString() }; path=/; SameSite=None;`;
+}

test/integration/page/MediaWiki/createTrackingImage.spec.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it, vi, vitest } from 'vitest';
+import { createImageCookieSetter } from '@src/page/MediaWiki/createImageCookieSetter';
+
+describe( 'createTrackingImage', () => {
+	it( 'creates the image cookie setter', () => {
+		const element = { src: '' };
+		const documentMock = {
+			createElement: vi.fn( () => element )
+		};
+		vitest.stubGlobal( 'document', documentMock );
+
+		createImageCookieSetter( 'fun', 424242, '//en.wikipedia.org/w/index.php?title=Special:HideBanners' );
+
+		expect( document.createElement ).toHaveBeenCalledOnce();
+		expect( element.src ).toBe( 'https://en.wikipedia.org/w/index.php?title=Special%3AHideBanners&duration=424242&category=fundraising&reason=fun' );
+	} );
+} );

test/integration/page/MediaWiki/setCookie.spec.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it } from 'vitest';
+import { setCookie } from '@src/page/MediaWiki/setCookie';
+
+describe( 'setCookie', () => {
+	it( 'sets the cookie', () => {
+		Object.defineProperty( document, 'cookie', { writable: true, configurable: true, value: '' } );
+
+		setCookie( 'testReason', new Date( 'August 29, 1997 02:14:00' ), 99999 );
+
+		expect( document.cookie ).toBe( [
+			'centralnotice_hide_fundraising=%7B%22v%22%3A1%2C%22created%22%3A872813640%2C%22reason%22%3A%22testReason%22%7D;',
+			'expires=Sat, 30 Aug 1997 04:00:39 GMT;',
+			'path=/;',
+			'SameSite=None;'
+		].join( ' ' ) );
+	} );
+} );