build: add esm build

.gitignore

@@ -30,3 +30,4 @@ yarn.lock
 package-lock.json
 /.history
 lib
+es

gulpfile.js

@@ -2,11 +2,31 @@ const gulp = require('gulp');
 const ts = require('gulp-typescript');
 const tsconfig = require('./tsconfig.json');
 
-gulp.task('default', () => gulp
-  .src('src/**/*.ts')
-  .pipe(ts({
-    ...tsconfig.compilerOptions,
-    declaration: true,
-  }))
-  .pipe(gulp.dest('lib'))
+gulp.task('lib', () =>
+  gulp
+    .src('src/**/*.ts')
+    .pipe(
+      ts({
+        ...tsconfig.compilerOptions,
+        declaration: true,
+      }),
+    )
+    .pipe(gulp.dest('lib')),
 );
+
+gulp.task('es', () =>
+  gulp
+    .src('src/**/*.ts')
+    .pipe(
+      ts({
+        ...tsconfig.compilerOptions,
+        target: 'es2015',
+        module: 'esnext',
+        declaration: true,
+        moduleResolution: 'node',
+      }),
+    )
+    .pipe(gulp.dest('es')),
+);
+
+gulp.task('default', gulp.parallel('lib', 'es'));

package.json

@@ -3,7 +3,7 @@
   "version": "4.0.1",
   "description": "Color palettes calculator of Ant Design",
   "main": "lib/index.js",
-  "module": "lib/index.js",
+  "module": "es/index.js",
   "files": [
     "lib"
   ],