add outDir option

index.mjs

@@ -6,6 +6,7 @@ import {resolve, basename, extname, dirname, relative, join} from 'node:path';
 export function buildConfig ({
 	manifest: manifestPathRelative,
 	platforms = [],
+	outDir = 'build/[platform]',
 	scriptPlugins = [],
 	sourcemap,
 }) {
@@ -51,10 +52,6 @@ export function buildConfig ({
 		return join(base, uniqueFileNameSegment(entryPath, ext));
 	}
 
-	function getOutputPathRelative (outputDir, platform, entryPath, ext) {
-		return join(outputDir, platform, getOutputFilename(entryPath, ext));
-	}
-
 	/** Scans a manifest for entrypoints */
 	function getEntryPointsFromManifest (manifestContent) {
 		const scriptEntrypointAbsolutePaths = [];
@@ -119,7 +116,10 @@ export function buildConfig ({
 		...scripts.map(entrypointPath => ({
 			input: relative(process.cwd(), entrypointPath),
 			output: {
-				file: getOutputPathRelative('build', platform, entrypointPath, 'js'),
+				file: join(
+					outDir.replace(/\[platform\]/g, platform),
+					getOutputFilename(entrypointPath, 'js'),
+				),
 				format: 'iife',
 				sourcemap,
 			},
@@ -131,7 +131,10 @@ export function buildConfig ({
 		{
 			input: manifestPathRelative,
 			output: {
-				file: `build/${platform}/manifest.json`,
+				file: join(
+					outDir.replace(/\[platform\]/g, platform),
+					`manifest.json`
+				),
 			},
 			plugins: [
 				{