fix ESM dist target

package.json

@@ -13,7 +13,7 @@
   },
   "scripts": {
     "prebuild": "npm run fix",
-    "build": "rollup ./src/index.js -c",
+    "build": "rm -rf dist && rollup ./src/index.js -c",
     "prepare": "npm run build",
     "test": "npm run test:lint && npm run test:build",
     "test:build": "npm run build",

rollup.config.js

@@ -1,11 +1,42 @@
-import { nodeResolve } from '@rollup/plugin-node-resolve';
 import commonjs from '@rollup/plugin-commonjs';
 import { babel } from '@rollup/plugin-babel';
 import eslint from '@rollup/plugin-eslint';
-import { terser } from "rollup-plugin-terser";
-import analyze from 'rollup-plugin-analyzer'
+import { terser } from 'rollup-plugin-terser';
+import analyze from 'rollup-plugin-analyzer';
+import { nodeResolve } from '@rollup/plugin-node-resolve';
+
+const plugins = [
+  !process.env.NOLINT &&
+    eslint({
+      include: 'src/**/*.js',
+      exclude: 'node_modules/**',
+    }),
+  babel({
+    include: 'src/**',
+    exclude: 'node_modules/**',
+    extensions: ['.js'],
+    babelHelpers: 'runtime',
+    presets: ['@babel/env', '@babel/preset-react'],
+    plugins: ['@babel/plugin-transform-runtime'],
+  }),
+  commonjs(),
+  terser(),
+  analyze({
+    stdout: true,
+    summaryOnly: true,
+  }),
+];
 
-export default {
+const external = [
+  '@babel/runtime',
+  '@kitware/vtk.js',
+  'prop-types',
+  'react',
+  'regenerator-runtime',
+];
+
+export default [
+  {
     input: 'src/index.js',
     output: [
       {
@@ -14,43 +45,33 @@ export default {
         preserveModules: true,
         preserveModulesRoot: 'src',
       },
+      {
+        file: 'dist/cjs/react-vtk.js',
+        format: 'cjs',
+      },
+    ],
+    external,
+    plugins,
+  },
+  {
+    input: 'src/index.js',
+    output: [
       {
         file: 'dist/umd/react-vtk.js',
         format: 'umd',
         exports: 'named',
         name: 'ReactVtkJS',
       },
-      {
-        file: 'dist/cjs/react-vtk.js',
-        format: 'cjs',
-      },
     ],
-    external: ['react', 'prop-types'],
+    external,
     plugins: [
       nodeResolve({
         // include: 'node_modules/**',
         // don't rely on node builtins for web
         preferBuiltins: false,
         browser: true,
       }),
-      !process.env.NOLINT &&
-      eslint({
-        include: 'src/**/*.js',
-        exclude: 'node_modules/**',
-      }),
-      babel({
-        include: 'src/**',
-        exclude: 'node_modules/**',
-        extensions: ['.js'],
-        babelHelpers: 'runtime',
-        presets: ['@babel/env', '@babel/preset-react'],
-        plugins:['@babel/plugin-transform-runtime'],
-      }),
-      commonjs(),
-      terser(),
-      analyze({
-        stdout: true,
-        summaryOnly: true,
-      }),
+      ...plugins,
     ],
-};
+  },
+];