dispatch custom event for winning message

Author: cemms1

dotcom-rendering/src/components/StickyBottomBanner.importable.tsx

@@ -310,9 +310,9 @@ export const StickyBottomBanner = ({
 		};
 
 		pickMessage(bannerConfig, renderingTarget)
-			.then((PickedBanner: () => MaybeFC) =>
-				setSelectedBanner(PickedBanner),
-			)
+			.then((PickedBanner: () => MaybeFC) => {
+				setSelectedBanner(PickedBanner);
+			})
 			.catch((e) =>
 				console.error(
 					`StickyBottomBanner pickMessage - error: ${String(e)}`,

dotcom-rendering/src/lib/messagePicker.ts

@@ -164,18 +164,26 @@ export const pickMessage = (
 			.then((winner) => {
 				clearAllTimeouts(candidateConfigsWithTimeout);
 
+				log(
+					'supporterRevenue',
+					`pickMessage for ${name}: ${JSON.stringify(winner)}}`,
+				);
+				document.dispatchEvent(
+					new CustomEvent<{
+						type: string;
+						winner: string | null;
+					}>('supporterRevenue:message-picker', {
+						detail: {
+							type: name,
+							winner: winner?.candidate.id ?? null,
+						},
+					}),
+				);
+
 				if (winner === null) {
-					log(
-						'supporterRevenue',
-						`pickMessage for ${name}: no winner, returning default value`,
-					);
 					resolve(defaultShow);
 				} else {
 					const { candidate, meta } = winner;
-					log(
-						'supporterRevenue',
-						`pickMessage for ${name}: winner is ${candidate.id}`,
-					);
 					resolve(() => candidate.show(meta));
 				}
 			})