no prefetching when wait is false (#15)

Author: mafintosh

lib/streams.js

@@ -92,7 +92,7 @@ class BlobReadStream extends Readable {
     this.id = id
     this.core = core.session({ wait: opts.wait, timeout: opts.timeout })
 
-    this._prefetch = opts.prefetch
+    this._prefetch = opts.wait === false ? noPrefetch : opts.prefetch
     this._lastPrefetch = null
     if (!this._prefetch) {
       const prefetcher = new SparsePrefetcher(opts)
@@ -174,3 +174,7 @@ module.exports = {
 }
 
 function noop () {}
+
+function noPrefetch () {
+  return null
+}