Change default name from snake_case to PascalCase

Author: msfragala

package.json

@@ -53,6 +53,7 @@
     "rollup-plugin-preserve-shebang": "^0.1.3",
     "rollup-plugin-sizes": "^0.4.2",
     "rollup-plugin-uglify": "^2.0.1",
+    "uppercamelcase": "^3.0.0",
     "yargs": "^10.0.3"
   },
   "devDependencies": {

src/index.js

@@ -16,12 +16,13 @@ import gzipSize from 'gzip-size';
 import prettyBytes from 'pretty-bytes';
 import shebangPlugin from 'rollup-plugin-preserve-shebang';
 import flow from 'rollup-plugin-flow';
+import pascalCase from 'uppercamelcase';
 
 const readFile = promisify(fs.readFile);
 const stat = promisify(fs.stat);
 const isDir = name => stat(name).then( stats => stats.isDirectory() ).catch( () => false );
 const isFile = name => stat(name).then( stats => stats.isFile() ).catch( () => false );
-const safeVariableName = name => name.replace(/(?:^[^a-z$_]|([^a-z0-9_$]+))/g, '_');
+const safeVariableName = name => pascalCase(name.toLowerCase().replace(/((^[^a-zA-Z]+)|[^\w.-])|([^a-zA-Z0-9]+$)/g, ''));
 
 const FORMATS = ['es', 'cjs', 'umd'];