ClientRouter: honor ctrl/shift... keys when clicking submit

.changeset/four-carpets-wear.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Allows the ClientRouter to open new tabs or windows when submitting forms by clicking while holding the Cmd, Ctrl, or Shift key.

packages/astro/components/ClientRouter.astro

@@ -37,6 +37,7 @@ const { fallback = 'animate' } = Astro.props;
 	import { init } from 'astro/virtual-modules/prefetch.js';
 
 	type Fallback = 'none' | 'animate' | 'swap';
+	let lastClickedElementLeavingWindow: EventTarget | null = null;
 
 	function getFallback(): Fallback {
 		const el = document.querySelector('[name="astro-view-transitions-fallback"]');
@@ -50,6 +51,13 @@ const { fallback = 'animate' } = Astro.props;
 		return el.dataset.astroReload !== undefined;
 	}
 
+	const leavesWindow = (ev: MouseEvent) =>
+		(ev.button && ev.button !== 0) || // left clicks only
+		ev.metaKey || // new tab (mac)
+		ev.ctrlKey || // new tab (windows)
+		ev.altKey || // download
+		ev.shiftKey; // new window
+
 	if (supportsViewTransitions || getFallback() !== 'none') {
 		if (import.meta.env.DEV && window.matchMedia('(prefers-reduced-motion)').matches) {
 			console.warn(
@@ -58,6 +66,9 @@ const { fallback = 'animate' } = Astro.props;
 		}
 		document.addEventListener('click', (ev) => {
 			let link = ev.target;
+
+			lastClickedElementLeavingWindow = leavesWindow(ev) ? link : null;
+
 			if (ev.composed) {
 				link = ev.composedPath()[0];
 			}
@@ -82,11 +93,7 @@ const { fallback = 'animate' } = Astro.props;
 				!link.href ||
 				(linkTarget && linkTarget !== '_self') ||
 				origin !== location.origin ||
-				ev.button !== 0 || // left clicks only
-				ev.metaKey || // new tab (mac)
-				ev.ctrlKey || // new tab (windows)
-				ev.altKey || // download
-				ev.shiftKey || // new window
+				lastClickedElementLeavingWindow ||
 				ev.defaultPrevented
 			) {
 				// No page transitions in these cases,
@@ -102,11 +109,15 @@ const { fallback = 'animate' } = Astro.props;
 
 		document.addEventListener('submit', (ev) => {
 			let el = ev.target as HTMLElement;
-			if (el.tagName !== 'FORM' || ev.defaultPrevented || isReloadEl(el)) {
+			const submitter = ev.submitter;
+
+			const clickedWithKeys = submitter && submitter === lastClickedElementLeavingWindow;
+			lastClickedElementLeavingWindow = null;
+
+			if (el.tagName !== 'FORM' || ev.defaultPrevented || isReloadEl(el) || clickedWithKeys) {
 				return;
 			}
 			const form = el as HTMLFormElement;
-			const submitter = ev.submitter;
 			const formData = new FormData(form, submitter);
 			// form.action and form.method can point to an <input name="action"> or <input name="method">
 			// in which case should fallback to the form attribute