Merge branch 'feat/trail' of https://github.com/jycouet/kit into pr/jycouet/15027

Author: teemingc

.changeset/thick-spiders-invite.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: Correctly handle shared memory when decoding binary form data

packages/kit/src/core/adapt/builder.spec.js

@@ -1,4 +1,4 @@
-import { existsSync, rmSync } from 'node:fs';
+import { copyFileSync, existsSync, mkdirSync, readFileSync, rmSync } from 'node:fs';
 import { join, dirname } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { assert, expect, test } from 'vitest';
@@ -72,3 +72,40 @@ test('compress files', async () => {
 	assert.ok(existsSync(target + '.br'));
 	assert.ok(existsSync(target + '.gz'));
 });
+
+test('instrument generates facade with posix paths', () => {
+	const fixtureDir = join(__dirname, 'fixtures/instrument');
+	const dest = join(__dirname, 'output');
+
+	rmSync(dest, { recursive: true, force: true });
+	mkdirSync(join(dest, 'server'), { recursive: true });
+	copyFileSync(join(fixtureDir, 'index.js'), join(dest, 'index.js'));
+	copyFileSync(
+		join(fixtureDir, 'server/instrumentation.server.js'),
+		join(dest, 'server/instrumentation.server.js')
+	);
+
+	const entrypoint = join(dest, 'index.js');
+	const instrumentation = join(dest, 'server', 'instrumentation.server.js');
+
+	// @ts-expect-error - we don't need the whole config for this test
+	const builder = create_builder({ route_data: [] });
+
+	builder.instrument({
+		entrypoint,
+		instrumentation,
+		module: { exports: ['default'] }
+	});
+
+	// Read the generated facade
+	const facade = readFileSync(entrypoint, 'utf-8');
+
+	// Verify it uses forward slashes (not backslashes)
+	// On Windows, path.relative() returns 'server\instrumentation.server.js'
+	// The fix ensures this becomes 'server/instrumentation.server.js'
+	expect(facade).toContain("import './server/instrumentation.server.js'");
+	expect(facade).not.toContain('\\');
+
+	// Cleanup
+	rmSync(dest, { recursive: true, force: true });
+});

packages/kit/src/core/adapt/fixtures/instrument/index.js

@@ -0,0 +1 @@
+export default {};

packages/kit/src/core/adapt/fixtures/instrument/server/instrumentation.server.js

@@ -0,0 +1 @@
+export {};

packages/kit/src/runtime/form-utils.js

@@ -220,7 +220,7 @@ export async function deserialize_binary_form(request) {
 			`Could not deserialize binary form: got version ${header[0]}, expected version ${BINARY_FORM_VERSION}`
 		);
 	}
-	const header_view = new DataView(header.buffer);
+	const header_view = new DataView(header.buffer, header.byteOffset, header.byteLength);
 	const data_length = header_view.getUint32(1, true);
 	const file_offsets_length = header_view.getUint16(5, true);
 

packages/kit/src/runtime/form-utils.spec.js

@@ -213,4 +213,33 @@ describe('binary form serializer', () => {
 		expect(await world_slice.text()).toBe('World');
 		expect(world_slice.type).toBe(file.type);
 	});
+
+	// Regression test for https://github.com/sveltejs/kit/issues/14971
+	test('DataView offset for shared memory', async () => {
+		const { blob } = serialize_binary_form({ a: 1 }, {});
+		const chunk = new Uint8Array(await blob.arrayBuffer());
+		// Simulate a stream that has extra bytes at the start in the underlying buffer
+		const stream = new ReadableStream({
+			start(controller) {
+				const offset_buffer = new Uint8Array(chunk.byteLength + 10);
+				offset_buffer.fill(255);
+				offset_buffer.set(chunk, 10);
+				controller.enqueue(offset_buffer.subarray(10));
+			}
+		});
+
+		const res = await deserialize_binary_form(
+			new Request('http://test', {
+				method: 'POST',
+				body: stream,
+				// @ts-expect-error duplex required in node
+				duplex: 'half',
+				headers: {
+					'Content-Type': BINARY_FORM_CONTENT_TYPE
+				}
+			})
+		);
+
+		expect(res.data).toEqual({ a: 1 });
+	});
 });