fix: use ReadableStream for response object if deno (#10495)

.changeset/cool-bulldogs-change.md

@@ -0,0 +1,7 @@
+---
+"astro": patch
+---
+
+This patch allows astro to run in node-compat mode in Deno. Deno doesn't support
+construction of response from async iterables in node-compat mode so we need to
+use ReadableStream.

packages/astro/src/runtime/server/render/page.ts

@@ -5,7 +5,7 @@ import type { AstroComponentFactory } from './index.js';
 import { isAstroComponentFactory } from './astro/index.js';
 import { renderToAsyncIterable, renderToReadableStream, renderToString } from './astro/render.js';
 import { encoder } from './common.js';
-import { isNode } from './util.js';
+import { isNode, isDeno } from './util.js';
 
 export async function renderPage(
 	result: SSRResult,
@@ -48,7 +48,9 @@ export async function renderPage(
 
 	let body: BodyInit | Response;
 	if (streaming) {
-		if (isNode) {
+		// isNode is true in Deno node-compat mode but response construction from
+		// async iterables is not supported, so we fallback to ReadableStream if isDeno is true.
+		if (isNode && !isDeno) {
 			const nodeBody = await renderToAsyncIterable(
 				result,
 				componentFactory,

packages/astro/src/runtime/server/render/util.ts

@@ -207,6 +207,8 @@ export function renderToBufferDestination(bufferRenderFunction: RenderFunction):
 
 export const isNode =
 	typeof process !== 'undefined' && Object.prototype.toString.call(process) === '[object process]';
+// @ts-expect-error: Deno is not part of the types.
+export const isDeno = typeof Deno !== 'undefined';
 
 // We can get rid of this when Promise.withResolvers() is ready
 export type PromiseWithResolvers<T> = {