first commit

src/util/logger.js

@@ -0,0 +1,18 @@
+'use strict';
+
+function createLogger({ verbose = false } = {}) {
+  const write = (stream, prefix, args) => {
+    stream.write(prefix + args.map(String).join(' ') + '\n');
+  };
+  return {
+    info: (...args) => write(process.stdout, '', args),
+    warn: (...args) => write(process.stderr, 'warning: ', args),
+    error: (...args) => write(process.stderr, 'error: ', args),
+    debug: (...args) => {
+      if (verbose) write(process.stdout, 'debug: ', args);
+    },
+    verbose,
+  };
+}
+
+module.exports = { createLogger };