fix middleware to work for various article types

Author: dskamiotis

dotcom-rendering/src/server/lib/get-abtests-from-query-params.ts

@@ -1,46 +1,52 @@
+import { isObject } from '@guardian/libs';
 import type { Handler } from 'express';
-import { validateAsFEArticle } from '../../model/validate';
 import { logger } from './logging';
 
+type AbServerSideTestType = {
+	config: {
+		serverSideABTests?: Record<string, string>;
+	};
+};
+
 const SAFE_AB_VALUE = /^[a-zA-Z0-9_-]+$/;
 const MAX_LENGTH = 100;
 
-export const getABTestsFromQueryParams: Handler = async (req, res, next) => {
+export const getABTestsFromQueryParams: Handler = (req, res, next) => {
 	try {
-		const frontendData = validateAsFEArticle(req.body);
-		const { config } = frontendData;
-		const queryParamsAb = req.query;
-		const filteredQuery: Record<string, string> = {};
+		if (isObject(req.body) && isObject(req.body.config)) {
+			const { config } = req.body as AbServerSideTestType;
+			const queryParamsAb = req.query;
+			const filteredQuery: Record<string, string> = {};
 
-		for (const [key, value] of Object.entries(queryParamsAb)) {
-			if (!key.startsWith('ab-') || typeof value !== 'string') {
-				continue;
-			}
+			for (const [key, value] of Object.entries(queryParamsAb)) {
+				if (!key.startsWith('ab-') || typeof value !== 'string') {
+					continue;
+				}
 
-			const testId = key.replace(/^ab-/, '');
+				const testId = key.replace(/^ab-/, '');
 
-			if (
-				testId.length > 0 &&
-				testId.length <= MAX_LENGTH &&
-				value.length > 0 &&
-				value.length <= MAX_LENGTH &&
-				SAFE_AB_VALUE.test(testId) &&
-				SAFE_AB_VALUE.test(value)
-			) {
-				filteredQuery[testId] = value;
-			} else {
-				logger.warn(
-					`Rejected invalid AB test parameter: ${key}=${value}`,
-				);
+				if (
+					testId.length > 0 &&
+					testId.length <= MAX_LENGTH &&
+					value.length > 0 &&
+					value.length <= MAX_LENGTH &&
+					SAFE_AB_VALUE.test(testId) &&
+					SAFE_AB_VALUE.test(value)
+				) {
+					filteredQuery[testId] = value;
+				} else {
+					logger.warn(
+						`Rejected invalid AB test parameter: ${key}=${value}`,
+					);
+				}
 			}
+			config.serverSideABTests = {
+				...config.serverSideABTests,
+				...filteredQuery,
+			};
 		}
-
-		config.serverSideABTests = {
-			...config.serverSideABTests,
-			...filteredQuery,
-		};
-		req.body = frontendData;
 	} catch (error) {
+		logger.error('Error processing AB test query params', error);
 		return next();
 	}
 	next();