conditional build for addons

bin/install-addons.js

@@ -0,0 +1,40 @@
+const path = require('path');
+const cp = require('child_process');
+const fs = require('fs');
+
+const PACKAGE_ROOT = path.join(__dirname, '..');
+
+// install addon deps
+const addonsPath = path.join(PACKAGE_ROOT, 'addons');
+if (fs.existsSync(addonsPath)) {
+  console.log('pulling addon dependencies...');
+
+  // whether to use yarn or npm
+  let hasYarn = false;
+  try {
+    cp.execSync('yarn --version').toString();
+    hasYarn = true;
+  } catch(e) {}
+
+  // walk all addon folders
+  fs.readdir(addonsPath, (err, files) => {
+    files.forEach(folder => {
+      const addonPath = path.join(addonsPath, folder);
+
+      // install only if there are dependencies listed
+      const packageJson = require(path.join(addonPath, 'package.json'));
+      if ((packageJson.devDependencies && Object.keys(packageJson.devDependencies).length)
+          || (packageJson.dependencies && Object.keys(packageJson.dependencies).length))
+      {
+        console.log('Preparing', folder);
+        if (hasYarn) {
+          cp.execSync('yarn', {cwd: addonPath});
+        } else {
+          cp.execSync('npm install', {cwd: addonPath});
+        }
+      } else {
+        console.log('Skipped', folder);
+      }
+    });
+  });
+}

package.json

@@ -8,6 +8,7 @@
   "repository": "https://github.com/xtermjs/xterm.js",
   "license": "MIT",
   "scripts": {
+    "postinstall": "node -e \"try { require('./bin/install-addons'); } catch(e) {}\"",
     "prepackage": "npm run build",
     "package": "webpack",
     "start": "node demo/start",