chore: add build by gulp (#8)

.gitignore

@@ -7,3 +7,4 @@ node_modules
 
 # Artifacts
 dist
+build

gulpfile.js

@@ -0,0 +1,75 @@
+/* eslint-env node */
+const path = require('path');
+const {task, src, dest, series, parallel} = require('gulp');
+const rimraf = require('rimraf');
+const ts = require('gulp-typescript');
+const replace = require('gulp-replace');
+const sass = require('gulp-dart-sass');
+
+const BUILD_DIR = path.resolve('build');
+
+task('clean', (done) => {
+    rimraf.sync(BUILD_DIR);
+    rimraf.sync('styles/**/*.css');
+    done();
+});
+
+function compileTs(modules = false) {
+    const tsProject = ts.createProject('tsconfig.json', {
+        declaration: true,
+        module: modules ? 'esnext' : 'commonjs',
+    });
+
+    return src([
+        'src/**/*.{ts,tsx}',
+        '!src/demo/**/*',
+        '!src/stories/**/*',
+        '!src/**/__stories__/**/*',
+        '!src/**/__tests__/**/*',
+    ])
+        .pipe(
+            replace(/import '.+\.scss';/g, (match) =>
+                modules ? match.replace('.scss', '.css') : '',
+            ),
+        )
+        .pipe(tsProject())
+        .pipe(dest(path.resolve(BUILD_DIR, modules ? 'esm' : 'cjs')));
+}
+
+task('compile-to-esm', () => {
+    return compileTs(true);
+});
+
+task('compile-to-cjs', () => {
+    return compileTs();
+});
+
+task('copy-i18n', () => {
+    return src(['src/**/i18n/*.json'])
+        .pipe(dest(path.resolve(BUILD_DIR, 'esm')))
+        .pipe(dest(path.resolve(BUILD_DIR, 'cjs')));
+});
+
+task('styles-components', () => {
+    return src(['src/components/**/*.scss', '!src/components/**/__stories__/**/*'])
+        .pipe(
+            sass({
+                includePaths: ['node_modules'],
+            }),
+        )
+        .pipe(sass().on('error', sass.logError))
+        .pipe(dest(path.resolve(BUILD_DIR, 'esm', 'components')))
+        .pipe(dest(path.resolve(BUILD_DIR, 'cjs', 'components')));
+});
+
+task(
+    'build',
+    series([
+        'clean',
+        parallel(['compile-to-esm', 'compile-to-cjs']),
+        'copy-i18n',
+        parallel(['styles-components']),
+    ]),
+);
+
+task('default', series(['build']));