Add peek method

index.js

@@ -2,12 +2,14 @@
 
 const Promise = require("bluebird");
 const propagateAbort = require("@ppstreams/propagate-abort");
+const propagatePeek = require("@ppstreams/propagate-peek");
 const { isEndOfStream } = require("@ppstreams/end-of-stream-marker");
 
 module.exports = function greedySinkStream(description, callback) {
 	return {
 		description: `greedy sink stream (${description})`,
 		abort: propagateAbort,
+		peek: propagatePeek,
 		read: function produceValue_greedySinkStream(source) {
 			let lastResult;
 

package.json

@@ -7,6 +7,7 @@
   "license": "WTFPL OR CC0-1.0",
   "dependencies": {
     "@ppstreams/propagate-abort": "^0.1.2",
+    "@ppstreams/propagate-peek": "^0.1.0",
     "bluebird": "^3.5.4"
   }
 }