Fix broken transform stream

README.md

@@ -23,7 +23,7 @@ $ node rle-decode.js < rle-encoded.txt
 ## Running tests
 Run `run-tests.sh` bash script to invoke the unit tests.
 
-They are written using my port of `jstinytest` which is bundled
+They are written using my fork of `jstinytest` which is bundled
 inside `tests/tinytest.js`.
 
 ## Licence

rle-decode.js

@@ -1,6 +1,6 @@
 "use strict";
 
-var transformStream= require("./transform-stream.js");
+var transformStream = require("./transform-stream.js");
 
 /*
 * run length decoding JS
@@ -18,4 +18,5 @@ function decode(data) {
     return result;
 }
 
-process.stdin.pipe(transformStream).pipe(process.stdout);
+var transform = transformStream.create( decode );
+process.stdin.pipe(transform).pipe(process.stdout);

rle-encode.js

@@ -36,4 +36,5 @@ function prettyPrint(rleData) {
     return [...rleData].join("");
 }
 
-process.stdin.pipe(transformStream).pipe(process.stdout);
+var transform = transformStream.create( encode );
+process.stdin.pipe(transform).pipe(process.stdout);

transform-stream.js

@@ -2,10 +2,15 @@
 
 var stream = require("stream");
 
-var transformStream = new stream.Transform();
-transformStream._transform = function transform(chunk, encoding, callback) {
-    transformStream.push( encode(chunk.toString()) );
-    callback();
-};
+// encode/decode-function passed in
+// strategy pattern, GoF
+function create( func ) {
+    var transformStream = new stream.Transform();
+    transformStream._transform = function transform(chunk, encoding, callback) {
+        transformStream.push( func(chunk.toString()) );
+        callback();
+    };
+    return transformStream;
+}
 
-module.exports = transformStream;
+module.exports = { create };