test/4.js :: added test to verify that source arrays are not modified

Author: mimetnet

test/4.js

@@ -0,0 +1,22 @@
+var test = require('tape')
+    , streamify = require('..')
+    , concat = require('concat-stream')
+;
+
+test('immutable', function(t) {
+    var s, a = [1, 2, 3, 4, 5];
+
+    if (Object && 'function' === typeof(Object.observe)) {
+        Object.observe(a, function (changes) {
+            t.fail('input array has been modified');
+        });
+    }
+
+    s = streamify(a);
+
+    s.pipe(concat({encoding: 'object'}, function(res) {
+        t.equal(1, arguments.length, 'concat returns 1 arg');
+        t.deepEqual(a, res, 'result array matches input');
+        t.end();
+    }));
+});