Readd Bootstrap.js

Author: wmonk

Diff for: bootstrap.js

@@ -0,0 +1,67 @@
+'use strict';
+
+const { execSync, spawn } = require('child_process');
+const { resolve } = require('path');
+const { existsSync } = require('fs');
+const { platform } = require('os');
+
+function shouldUseYarn() {
+  try {
+    execSync('yarnpkg --version', { stdio: 'ignore' });
+    return true;
+  } catch (e) {
+    return false;
+  }
+}
+
+function shouldUseNpmConcurrently() {
+  try {
+    const versionString = execSync('npm --version');
+    const m = /^(\d+)[.]/.exec(versionString);
+    // NPM >= 5 support concurrent installs
+    return Number(m[1]) >= 5;
+  } catch (e) {
+    return false;
+  }
+}
+
+const yarn = shouldUseYarn();
+const windows = platform() === 'win32';
+const lerna = resolve(
+  __dirname,
+  'node_modules',
+  '.bin',
+  windows ? 'lerna.cmd' : 'lerna'
+);
+
+if (!existsSync(lerna)) {
+  if (yarn) {
+    console.log('Cannot find lerna. Please run `yarn --check-files`.');
+  } else {
+    console.log(
+      'Cannot find lerna. Please remove `node_modules` and run `npm install`.'
+    );
+  }
+  process.exit(1);
+}
+
+let child;
+if (yarn) {
+  // Yarn does not support concurrency
+  child = spawn(lerna, ['bootstrap', '--npm-client=yarn', '--concurrency=1'], {
+    stdio: 'inherit',
+  });
+} else {
+  let args = ['bootstrap'];
+  if (
+    // The Windows filesystem does not handle concurrency well
+    windows ||
+    // Only newer npm versions support concurrency
+    !shouldUseNpmConcurrently()
+  ) {
+    args.push('--concurrency=1');
+  }
+  child = spawn(lerna, args, { stdio: 'inherit' });
+}
+
+child.on('close', code => process.exit(code));