Add standalone build

.gitignore

@@ -3,3 +3,6 @@ node_modules
 .history
 plugin.js
 plugin.js.map
+standalone.js
+standalone.js.map
+esm

package.json

@@ -3,12 +3,28 @@
     "version": "2.3.1",
     "description": "Svelte plugin for prettier",
     "main": "plugin.js",
+    "module": "esm/plugin.mjs",
+    "exports": {
+        ".": {
+            "browser": {
+                "import": "./esm/standalone.mjs",
+                "default": "./standalone.js"
+            },
+            "default": "./plugin.js"
+        },
+        "./standalone": {
+            "import": "./esm/standalone.mjs",
+            "default": "./standalone.js"
+        }
+    },
     "files": [
         "plugin.js",
-        "plugin.js.map"
+        "plugin.js.map",
+        "esm/**/*.mjs",
+        "esm/**/*.mjs.map"
     ],
     "scripts": {
-        "build": "rollup -c",
+        "build": "rollup -c && rollup -c rollup.standalone.cjs.config.js && rollup -c rollup.standalone.esm.config.js",
         "test": "ava",
         "prepare": "npm run build",
         "prepublishOnly": "npm test"
@@ -28,6 +44,8 @@
     },
     "homepage": "https://github.com/sveltejs/prettier-plugin-svelte#readme",
     "devDependencies": {
+        "@rollup/plugin-alias": "^3.1.4",
+        "@rollup/plugin-inject": "^4.0.2",
         "@types/node": "^10.12.18",
         "@types/prettier": "^2.1.6",
         "ava": "3.15.0",
@@ -44,5 +62,8 @@
     "peerDependencies": {
         "prettier": "^1.16.4 || ^2.0.0",
         "svelte": "^3.2.0"
+    },
+    "dependencies": {
+        "buffer": "^5.7.1"
     }
 }

rollup.standalone.cjs.config.js

@@ -0,0 +1,29 @@
+import resolve from '@rollup/plugin-node-resolve';
+import commonjs from '@rollup/plugin-commonjs';
+import typescript from 'rollup-plugin-typescript';
+import inject from '@rollup/plugin-inject';
+import alias from '@rollup/plugin-alias';
+
+export default {
+    input: 'src/index.ts',
+    plugins: [
+        alias({
+            entries: [{ find: /^prettier$/gm, replacement: `prettier/standalone` }],
+        }),
+        resolve({
+            preferBuiltins: false,
+            browser: true,
+        }),
+        commonjs(),
+        typescript({}),
+        inject({
+            Buffer: ['buffer', 'Buffer'],
+        }),
+    ],
+    external: ['prettier/standalone', 'svelte/compiler'],
+    output: {
+        file: 'standalone.js',
+        format: 'cjs',
+        sourcemap: true,
+    },
+};

rollup.standalone.esm.config.js

@@ -0,0 +1,31 @@
+import resolve from '@rollup/plugin-node-resolve';
+import commonjs from '@rollup/plugin-commonjs';
+import typescript from 'rollup-plugin-typescript';
+import inject from '@rollup/plugin-inject';
+import alias from '@rollup/plugin-alias';
+import path from 'path';
+
+const srcDir = path.resolve(__dirname, 'src');
+export default {
+    input: 'src/index.ts',
+    plugins: [
+        alias({
+            entries: [{ find: /^prettier$/gm, replacement: `${srcDir}/standalone-shim` }],
+        }),
+        resolve({
+            preferBuiltins: false,
+            browser: true,
+        }),
+        commonjs(),
+        typescript({}),
+        inject({
+            Buffer: ['buffer', 'Buffer'],
+        }),
+    ],
+    external: ['prettier/esm/standalone', 'svelte/compiler'],
+    output: {
+        file: 'esm/standalone.mjs',
+        format: 'esm',
+        sourcemap: true,
+    },
+};

src/index.ts

@@ -3,6 +3,7 @@ import { print } from './print';
 import { ASTNode } from './print/nodes';
 import { embed } from './embed';
 import { snipScriptAndStyleTagContent } from './lib/snipTagContent';
+import { parse as parseSvelte } from 'svelte/compiler';
 
 function locStart(node: any) {
     return node.start;
@@ -25,7 +26,8 @@ export const parsers: Record<string, Parser> = {
     svelte: {
         parse: (text) => {
             try {
-                return <ASTNode>{ ...require(`svelte/compiler`).parse(text), __isRoot: true };
+                // @ts-ignore
+                return <ASTNode>{ ...parseSvelte(text), __isRoot: true };
             } catch (err) {
                 if (err.start != null && err.end != null) {
                     // Prettier expects error objects to have loc.start and loc.end fields.

src/standalone-shim.mjs

@@ -0,0 +1,2 @@
+import prettier from 'prettier/esm/standalone';
+export const doc = prettier.doc;