add functionality for once

README.md

@@ -17,12 +17,18 @@ Uses [through2](https://github.com/rvagg/through2) as opposed to `node` core's [
 
 ## Usage
 
-### wait(timeout)
+### wait(timeout[, options])
 
 #### timeout
 
 > _{number}_ The delay in `ms` to pass to [setTimeout](https://nodejs.org/api/timers.html#timers_settimeout_callback_delay_arg).
 
+### options
+
+#### once
+
+> _{boolean}_ The delay will only happen for the first chunk to enter the stream; all other chunks will pass through immediately.
+
 ## Example
 
 ```js

index.js

@@ -13,16 +13,28 @@
    *
    * @name wait
    * @param {number} timeout - The duration to wait, in milliseconds.
+   * @param {object} [options] - The options to modify the behavior of wait().
+   * @param {boolean} [options.once] - Only wait for the very first chunk into the pipe.
    * @return {stream} - The node stream for piping.
    */
-  function wait(timeout) {
+  function wait(timeout, options) {
+    options = options || {};
+    var waited = false;
+
     return through2.obj(function(chunk, enc, callback) {
       var stream = this;
 
-      setTimeout(function() {
+      if (!options.once || !waited) {
+        setTimeout(function() {
+          stream.push(chunk);
+          callback();
+        }, timeout || 0);
+
+        waited = true;
+      } else {
         stream.push(chunk);
         callback();
-      }, timeout || 0);
+      }
     });
   }
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "wait-stream",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "description": "Simple wait module for streams3 in node",
   "repository": "justinhelmer/wait-stream",
   "keywords": [