From 905a6dd1491705c1154b6679a67c1eb1ffe7eef5 Mon Sep 17 00:00:00 2001
From: Harttle <harttle@harttle.com>
Date: Mon, 15 Aug 2022 02:34:23 +0800
Subject: [PATCH] fix: target ES6 for ESM bundles, fixes #526

---
 .eslintrc.json                        |  2 +-
 package.json                          |  4 ++--
 rollup.config.ts => rollup.config.mjs | 19 ++++++++++---------
 3 files changed, 13 insertions(+), 12 deletions(-)
 rename rollup.config.ts => rollup.config.mjs (89%)

diff --git a/.eslintrc.json b/.eslintrc.json
index 7f129f6c42..cffae27a9c 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -32,7 +32,7 @@
     "@typescript-eslint/no-unused-vars": ["error", { "vars": "all", "args": "none", "ignoreRestSiblings": false }]
   },
   "overrides": [{
-    "files": ["**/*.js", "*.js"],
+    "files": ["**/*.js", "**/*.mjs"],
     "rules": {
       "@typescript-eslint/no-var-requires": "off"
     }
diff --git a/package.json b/package.json
index a0023812f6..631ce00716 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,7 @@
   },
   "types": "dist/liquid.d.ts",
   "scripts": {
-    "lint": "eslint \"**/*.ts\" .",
+    "lint": "eslint \"**/*.mjs\" \"**/*.ts\" .",
     "check": "npm run build && npm test && npm run lint && npm run perf:diff",
     "test": "nyc mocha \"test/**/*.ts\"",
     "test:e2e": "mocha \"test/e2e/**/*.ts\"",
@@ -20,7 +20,7 @@
     "perf:engines": "cd benchmark && npm run engines",
     "postversion": "npm run build:dist",
     "build": "npm run build:dist && npm run build:docs",
-    "build:dist": "rollup -c rollup.config.ts",
+    "build:dist": "rollup -c rollup.config.mjs",
     "build:docs": "bin/build-docs.sh"
   },
   "bin": {
diff --git a/rollup.config.ts b/rollup.config.mjs
similarity index 89%
rename from rollup.config.ts
rename to rollup.config.mjs
index 9fea0bd205..d8ff2d9d80 100644
--- a/rollup.config.ts
+++ b/rollup.config.mjs
@@ -1,9 +1,10 @@
 import { uglify } from 'rollup-plugin-uglify'
-import pkg from './package.json'
 import typescript from 'rollup-plugin-typescript2'
 import replace from 'rollup-plugin-replace'
 import versionInjector from 'rollup-plugin-version-injector'
+import { createRequire } from 'module'
 
+const pkg = createRequire(import.meta.url)('./package.json')
 const version = process.env.VERSION || pkg.version
 const sourcemap = true
 const banner = `/*
@@ -14,16 +15,16 @@ const banner = `/*
 const treeshake = {
   propertyReadSideEffects: false
 }
-const tsconfig = {
+const tsconfig = (target) => ({
   tsconfigOverride: {
     include: [ 'src' ],
     exclude: [ 'test', 'benchmark' ],
     compilerOptions: {
-      target: 'es5',
+      target,
       module: 'ES2015'
     }
   }
-}
+})
 const versionInjection = versionInjector({
   injectInComments: false,
   injectInTags: {
@@ -60,7 +61,7 @@ const nodeCjs = {
     banner
   }],
   external: ['path', 'fs'],
-  plugins: [versionInjection, typescript(tsconfig)],
+  plugins: [versionInjection, typescript(tsconfig('es5'))],
   treeshake,
   input
 }
@@ -75,7 +76,7 @@ const nodeEsm = {
   plugins: [
     versionInjection,
     replace(esmRequire),
-    typescript(tsconfig)
+    typescript(tsconfig('es6'))
   ],
   treeshake,
   input
@@ -92,7 +93,7 @@ const browserEsm = {
     versionInjection,
     replace(browserFS),
     replace(browserStream),
-    typescript(tsconfig)
+    typescript(tsconfig('es6'))
   ],
   treeshake,
   input
@@ -110,7 +111,7 @@ const browserUmd = {
     versionInjection,
     replace(browserFS),
     replace(browserStream),
-    typescript(tsconfig)
+    typescript(tsconfig('es5'))
   ],
   treeshake,
   input
@@ -128,7 +129,7 @@ const browserMin = {
     versionInjection,
     replace(browserFS),
     replace(browserStream),
-    typescript(tsconfig),
+    typescript(tsconfig('es5')),
     uglify()
   ],
   treeshake,