1 files changed, 54 insertions, 0 deletions
diff --git a/node_modules/unique-stream/index.js b/node_modules/unique-stream/index.js
new file mode 100644
index 000000000..0c13168e5
--- /dev/null
+++ b/node_modules/unique-stream/index.js
@@ -0,0 +1,54 @@
+var Stream = require('stream');
+
+function prop(propName) {
+  return function (data) {
+    return data[propName];
+  };
+}
+
+module.exports = unique;
+function unique(propName) {
+  var keyfn = JSON.stringify;
+  if (typeof propName === 'string') {
+    keyfn = prop(propName);
+  } else if (typeof propName === 'function') {
+    keyfn = propName;
+  }
+  var seen = {};
+  var s = new Stream();
+  s.readable = true;
+  s.writable = true;
+  var pipes = 0;
+
+  s.write = function (data) {
+    var key = keyfn(data);
+    if (seen[key] === undefined) {
+      seen[key] = true;
+      s.emit('data', data);
+    }
+  };
+
+  var ended = 0;
+  s.end = function (data) {
+    if (arguments.length) s.write(data);
+    ended++;
+    if (ended === pipes || pipes === 0) {
+      s.writable = false;
+      s.emit('end');
+    }
+  };
+
+  s.destroy = function (data) {
+    s.writable = false;
+  };
+
+  s.on('pipe', function () {
+    pipes++;
+  });
+
+  s.on('unpipe', function () {
+    pipes--;
+  });
+
+  return s;
+}