From cd95654a970046e6bd03a7081dfd5f27ec0d4abc Mon Sep 17 00:00:00 2001
From: Alex Rock <pierstoval@gmail.com>
Date: Fri, 14 Aug 2020 05:36:55 +0200
Subject: [PATCH] Allow using the compiler as an ESM module (#4972)

---
 rollup.config.js | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/rollup.config.js b/rollup.config.js
index 6f3d893a33..82a2b9ae34 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -99,12 +99,20 @@ export default [
 			json(),
 			ts_plugin
 		],
-		output: {
-			file: 'compiler.js',
-			format: is_publish ? 'umd' : 'cjs',
-			name: 'svelte',
-			sourcemap: true,
-		},
+		output: [
+			{
+				file: 'compiler.js',
+				format: is_publish ? 'umd' : 'cjs',
+				name: 'svelte',
+				sourcemap: true,
+			},
+			{
+				file: 'compiler.mjs',
+				format: 'esm',
+				name: 'svelte',
+				sourcemap: true,
+			}
+		],
 		external: is_publish
 			? []
 			: id => id === 'acorn' || id === 'magic-string' || id.startsWith('css-tree')