add basic build script

rollup.config.js

@@ -0,0 +1,66 @@
+import path from 'path'
+import minimist from 'minimist'
+import { getPackages } from '@lerna/project'
+import filterPackages from '@lerna/filter-packages'
+import batchPackages from '@lerna/batch-packages'
+import typescript from 'rollup-plugin-typescript2'
+import resolve from '@rollup/plugin-node-resolve'
+import commonjs from '@rollup/plugin-commonjs'
+import babel from '@rollup/plugin-babel'
+import { terser } from 'rollup-plugin-terser'
+
+async function getSortedPackages(scope, ignore) {
+  const packages = await getPackages(__dirname)
+  const filtered = filterPackages(packages, scope, ignore, false)
+
+  return batchPackages(filtered).reduce((arr, batch) => arr.concat(batch), [])
+}
+
+async function main(commandLineArgs) {
+  const config = []
+  // Support --scope and --ignore globs if passed in via commandline
+  const { scope, ignore } = minimist(process.argv.slice(2))
+  const packages = await getSortedPackages(scope, ignore)
+
+  // prevent rollup warning
+  delete commandLineArgs.scope
+  delete commandLineArgs.ignore
+
+  packages.forEach(pkg => {
+    /* Absolute path to package directory */
+    const basePath = path.relative(__dirname, pkg.location)
+    /* Absolute path to input file */
+    const input = path.join(basePath, 'index.ts')
+    /* "main" field from package.json file. */
+    const { main } = pkg.toJSON()
+    /* Push build config for this package. */
+
+    config.push({
+      input,
+      output: [
+        {
+          file: path.join(basePath, main),
+          format: 'cjs',
+        },
+      ],
+      external: [
+        ...Object.keys(pkg.dependencies || {}),
+        ...Object.keys(pkg.devDependencies || {}),
+        ...Object.keys(pkg.peerDependencies || {}),
+      ],
+      plugins: [
+        resolve(),
+        commonjs(),
+        typescript(),
+        babel({
+          babelHelpers: 'bundled',
+        }),
+        terser(),
+      ],
+    })
+  })
+
+  return config
+}
+
+export default main