fix: better assetsInlineLimit runtime type checking

.changeset/late-bears-collect.md

@@ -0,0 +1,5 @@
+---
+"astro": patch
+---
+
+Improves runtime type-checking with the vite.build.assetsInlineLimit configuration option, which could result in errors when passing invalid options like strings. Astro now automatically casts this to a number to match the Vite behaviour.

packages/astro/src/core/build/plugins/util.ts

@@ -75,13 +75,14 @@ export function shouldInlineAsset(
 	assetPath: string,
 	assetsInlineLimit: NonNullable<BuildOptions['assetsInlineLimit']>
 ) {
-	if (typeof assetsInlineLimit === 'number') {
-		return Buffer.byteLength(assetContent) < assetsInlineLimit;
+	if (typeof assetsInlineLimit === 'function') {
+		const result = assetsInlineLimit(assetPath, Buffer.from(assetContent));
+		if (result != null) {
+			return result;
+		}
 	}
-
-	const result = assetsInlineLimit(assetPath, Buffer.from(assetContent));
-	if (result != null) {
-		return result;
+	if (typeof assetsInlineLimit === 'number' || typeof assetsInlineLimit === 'string') {
+		return Buffer.byteLength(assetContent) < Number(assetsInlineLimit);
 	}
 
 	return Buffer.byteLength(assetContent) < 4096; // Fallback to 4096kb by default (same as Vite)