add bundle-time error for non-web-workers where target is node

Author: hughrawlinson

src/utils/buildWorkerCode.js

@@ -59,6 +59,9 @@ export default WorkerFactory;
 
 function buildWorkerCode(source, sourcemap = null, optionsArg = kDefaultsOptions) {
     const options = Object.assign({}, kDefaultsOptions, optionsArg);
+    if (options.targetPlatform === 'node' && options.type !== 'web-worker') {
+        throw new Error(`rollup-plugin-web-worker-loader only supports web-workers in node. ${options.type} is unavailable.`);
+    }
     const factoryFuncName = getFactoryFuncName(options);
     const argsString = getArgsString(source, sourcemap, options);
     return buildWorkerSource(options, factoryFuncName, argsString);