feat: add unit suffix support for BODY_SIZE_LIMIT

.changeset/great-hats-cough.md

@@ -0,0 +1,5 @@
+---
+"@sveltejs/adapter-node": minor
+---
+
+feat: add unit suffixes to the `BODY_SIZE_LIMIT` environment variable

documentation/docs/25-build-and-deploy/40-adapter-node.md

@@ -118,6 +118,8 @@ We instead read from the _right_, accounting for the number of trusted proxies.
 
 The maximum request body size to accept in bytes including while streaming. Defaults to 512kb. You can disable this option with a value of 0 and implement a custom check in [`handle`](hooks#server-hooks-handle) if you need something more advanced.
 
+The body size variable can also specify unit suffixes for kilobytes (`K`), megabytes (`M`), and gigabytes (`G`). For example `512K` and `1M`
+
 ## Options
 
 The adapter can be configured with various options:

packages/adapter-node/src/handler.js

@@ -19,7 +19,21 @@ const address_header = env('ADDRESS_HEADER', '').toLowerCase();
 const protocol_header = env('PROTOCOL_HEADER', '').toLowerCase();
 const host_header = env('HOST_HEADER', 'host').toLowerCase();
 const port_header = env('PORT_HEADER', '').toLowerCase();
-const body_size_limit = Number(env('BODY_SIZE_LIMIT', '524288'));
+
+/**
+ * @param {string} bytes
+ */
+function parse_body_size_limit(bytes) {
+	const multiplier =
+		{
+			K: 1024,
+			M: 1024 * 1024,
+			G: 1024 * 1024 * 1024
+		}[bytes[bytes.length - 1]?.toUpperCase()] ?? 1;
+	return Number(multiplier != 1 ? bytes.substring(0, bytes.length - 1) : bytes) * multiplier;
+}
+
+const body_size_limit = parse_body_size_limit(env('BODY_SIZE_LIMIT', '512K'));
 
 if (isNaN(body_size_limit)) {
 	throw new Error(