feat(build): add es2015 build target support (#3202)

* feat(build): add es2015 support

* refactor(build): use await instead of promises

* feat(build): clear tmp folder, fix es2015 field in package.json

package.json

@@ -22,10 +22,11 @@
     "disable-lint": "tslint \"**/*.ts\" -c tslint.json --fix --type-check -t prose -e \"node_modules/**\" -e \"dist/**\" -e \"temp/**\" -e \"scripts/docs/**\"",
     "flow.changelog": "conventional-changelog -i CHANGELOG.md -s -p angular",
     "flow.github-release": "conventional-github-releaser -p angular",
-    "build": "run-s build.ngm build.sass",
+    "build": "run-s build.ngm build.sass build.es2015",
     "build.sass": "node-sass --recursive src --output dist --source-map true --source-map-contents sass",
     "build.ngm": "ngm build -p src --clean",
     "build.watch": "ngm build -p src --watch --skip-bundles",
+    "build.es2015": "node ./scripts/es2015/bundle.es2015.js",
     "start": "ng serve --aot --host 0.0.0.0",
     "pretest": "run-s lint build link",
     "test": "ng test -sr",
@@ -134,6 +135,9 @@
     "protractor": "5.1.2",
     "reflect-metadata": "0.1.10",
     "require-dir": "0.3.2",
+    "rollup": "0.52.1",
+    "rollup-plugin-commonjs": "8.2.6",
+    "rollup-plugin-node-resolve": "3.0.0",
     "rxjs": "5.4.3",
     "ts-helpers": "^1.1.1",
     "ts-loader": "3.0.5",

scripts/es2015/bundle.es2015.js

@@ -0,0 +1,30 @@
+'use strict';
+const path = require('path');
+const execa = require('execa');
+const fs = require('fs-extra');
+const del = require('del');
+const inlineResources = require('ngm-cli/helpers/inline-resources');
+const src = 'src';
+const tmp = '.tmp';
+const dist = 'dist-es2015';
+const tsconfigPath = '.tmp/tsconfig.json';
+
+async function createEs2015Bundle() {
+  await del(tmp);
+  console.log('Copying src to temp folder');
+  await fs.copy(src, tmp);
+  const tsconfig = require(path.resolve(tsconfigPath));
+  tsconfig.compilerOptions.target = 'es2015';
+  tsconfig.compilerOptions.outDir = '../' + dist;
+  await fs.writeFile(tsconfigPath, JSON.stringify(tsconfig), 'utf8');
+  console.log('Inlining templates and styles');
+  await inlineResources.inlineResources(tmp);
+  console.log('Compiling library from temp folder');
+  await execa('ngc', ['-p', tmp], { preferLocal: true });
+  console.log('Bundling es2015 bundle');
+  await execa('rollup --config ./scripts/es2015/es2015.config.js', { shell: true });
+  console.log('Removing temp folders');
+  await del([tmp, dist]);
+}
+createEs2015Bundle();
+

scripts/es2015/es2015.config.js

@@ -0,0 +1,37 @@
+'use strict';
+const fs = require('fs-extra');
+const rollup = require('rollup');
+const resolve = require('rollup-plugin-node-resolve');
+const commonjs = require('rollup-plugin-commonjs');
+const ROLLUP_GLOBALS = require('./rollup.globals');
+const libName = 'ngx-bootstrap';
+const PATH_SRC = 'dist-es2015/';
+const PATH_DIST = 'dist/bundles/';
+
+export default {
+  input: PATH_SRC + 'index.js',
+  output: {
+    format: 'es',
+    file: PATH_DIST + libName + '.es2015.js',
+    sourcemap: true,
+    name: libName
+  },
+  external: Object.keys(ROLLUP_GLOBALS),
+  plugins: [
+    resolve({
+      module: true,
+      main: true
+    }),
+    commonjs({
+      include: 'node_modules/**',
+    })
+  ],
+  onwarn: warning => {
+    const skip_codes = [
+      'THIS_IS_UNDEFINED',
+      'MISSING_GLOBAL_NAME'
+    ];
+    if (skip_codes.indexOf(warning.code) != -1) return;
+    console.error(warning);
+  }
+};