revert: allow users to still use USER_AGENT

Removed from documentation, but older users can utilize
until fully removed in 4.0.0

src/config.ts

@@ -173,7 +173,8 @@ const browser = {
 		process.env.PAGE_SLEEP_MAX,
 		5000
 	),
-	open: envOrBoolean(process.env.OPEN_BROWSER)
+	open: envOrBoolean(process.env.OPEN_BROWSER),
+	userAgent: ''
 };
 
 const docker = envOrBoolean(process.env.DOCKER);

src/index.ts

@@ -48,6 +48,8 @@ async function main() {
 		headless: config.browser.isHeadless
 	});
 
+	config.browser.userAgent = await browser.userAgent();
+
 	for (const store of storeList.values()) {
 		logger.debug('store links', {meta: {links: store.links}});
 		if (store.setupAction !== undefined) {

src/store/lookup.ts

@@ -163,7 +163,7 @@ async function lookup(browser: Browser, store: Store) {
 		await page.setRequestInterception(true);
 
 		page.setDefaultNavigationTimeout(config.page.timeout);
-		await page.setUserAgent(await getRandomUserAgent(browser));
+		await page.setUserAgent(await getRandomUserAgent());
 
 		let adBlockRequestHandler: any;
 		let pageProxy;

src/util.ts

@@ -58,7 +58,7 @@ export async function usingPage<T>(
 ): Promise<T> {
 	const page = await browser.newPage();
 	page.setDefaultNavigationTimeout(config.page.timeout);
-	await page.setUserAgent(await getRandomUserAgent(browser));
+	await page.setUserAgent(await getRandomUserAgent());
 
 	try {
 		return await cb(page, browser);
@@ -79,11 +79,24 @@ export async function closePage(page: Page) {
 	await page.close();
 }
 
-export async function getRandomUserAgent(browser: Browser): Promise<string> {
+export async function getRandomUserAgent(): Promise<string> {
+	const deprecatedUserAgent = (process.env.USER_AGENT
+		? process.env.USER_AGENT.includes('\n')
+			? process.env.USER_AGENT.split('\n')
+			: process.env.USER_AGENT.split(',')
+		: []
+	).map((s) => s.trim());
+
+	if (deprecatedUserAgent.length > 0) {
+		return deprecatedUserAgent[
+			Math.floor(Math.random() * deprecatedUserAgent.length)
+		];
+	}
+
 	const userAgent =
 		getRandom((ua) => {
 			return ua.browserName === 'Chrome' && ua.browserVersion > '20';
-		}) ?? (await browser.userAgent());
+		}) ?? config.browser.userAgent;
 
 	logger.debug('user agent', userAgent);