From f7f2d2638e9e8dc4679d2bc5b5c73c1eb0de5e5b Mon Sep 17 00:00:00 2001
From: Pete Bacon Darwin <pbacondarwin@cloudflare.com>
Date: Mon, 19 Oct 2026 11:56:34 +0100
Subject: [PATCH] [vite-plugin] Backport October 19 SDK release coverage to v1

---
 .changeset/v1-sdk-release-16313.md            |  7 ++
 .../src/__tests__/sdk-release.spec.ts         | 73 +++++++++++++++++++
 2 files changed, 80 insertions(+)
 create mode 100644 .changeset/v1-sdk-release-16313.md
 create mode 100644 packages/vite-plugin-cloudflare/src/__tests__/sdk-release.spec.ts

diff --git a/.changeset/v1-sdk-release-16313.md b/.changeset/v1-sdk-release-16313.md
new file mode 100644
index 0000000000..6f9cdf8ced
--- /dev/null
+++ b/.changeset/v1-sdk-release-16313.md
@@ -0,0 +1,7 @@
+---
+"@cloudflare/vite-plugin": patch
+---
+
+Align local development and preview with the October 19 Miniflare release
+
+Use the compatible SDK release with Miniflare 5.20261019.0-beta for Vite development and generated preview output. Earlier backports supply its coupled runtime and deployment helper versions; this release retains its own dev and preview regression coverage.
diff --git a/packages/vite-plugin-cloudflare/src/__tests__/sdk-release.spec.ts b/packages/vite-plugin-cloudflare/src/__tests__/sdk-release.spec.ts
new file mode 100644
index 0000000000..841e0baa81
--- /dev/null
+++ b/packages/vite-plugin-cloudflare/src/__tests__/sdk-release.spec.ts
@@ -0,0 +1,73 @@
+import { realpath, writeFile } from "node:fs/promises";
+import { runInTempDir } from "@cloudflare/workers-utils/test-helpers";
+import { createBuilder, createServer, preview } from "vite";
+import { test, vi } from "vitest";
+import { cloudflare } from "../../dist/index.mjs";
+
+runInTempDir();
+
+test.for(["dev", "preview"] as const)(
+	"runs the published v1 plugin with the October 19 SDK in %s",
+	async (mode, { expect, onTestFinished }) => {
+		const root = await realpath(process.cwd());
+		process.chdir(root);
+		vi.stubEnv("PWD", root);
+		onTestFinished(() => {
+			vi.unstubAllEnvs();
+		});
+		await writeFile("package.json", JSON.stringify({ type: "module" }));
+		await writeFile(
+			"wrangler.json",
+			JSON.stringify({
+				name: "v1-sdk-release",
+				main: "index.js",
+				compatibility_date: "2026-10-19",
+				vars: { RELEASE: "october-19" },
+			})
+		);
+		await writeFile(
+			"index.js",
+			`
+export default {
+ fetch(request, env) {
+  return Response.json({ release: env.RELEASE, path: new URL(request.url).pathname });
+ },
+};
+`
+		);
+		const config = {
+			root,
+			configFile: false as const,
+			logLevel: "silent" as const,
+			plugins: [
+				cloudflare({
+					inspectorPort: false,
+					persistState: false,
+					remoteBindings: false,
+				}),
+			],
+			server: { port: 0 },
+			preview: { port: 0 },
+		};
+		if (mode === "preview") {
+			const builder = await createBuilder(config);
+			await builder.buildApp();
+		}
+		const server =
+			mode === "dev" ? await createServer(config) : await preview(config);
+		onTestFinished(() => server.close());
+		if ("listen" in server) {
+			await server.listen();
+		}
+		const url = server.resolvedUrls?.local[0];
+		if (!url) {
+			throw new Error("The v1 plugin did not start a local server");
+		}
+		const response = await fetch(new URL("/release-check", url));
+		expect(response.status).toBe(200);
+		expect(await response.json()).toEqual({
+			release: "october-19",
+			path: "/release-check",
+		});
+	}
+);