1 files changed, 48 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..a2b292069
--- /dev/null
+++ b/node_modules/unique-stream/index.js
@@ -0,0 +1,48 @@
+'use strict';
+
+var filter = require('through2-filter').obj;
+var stringify = require("json-stable-stringify");
+
+var ES6Set;
+if (typeof global.Set === 'function') {
+  ES6Set = global.Set;
+} else {
+  ES6Set = function() {
+    this.keys = [];
+    this.has = function(val) {
+      return this.keys.indexOf(val) !== -1;
+    },
+    this.add = function(val) {
+      this.keys.push(val);
+    }
+  }
+}
+
+function prop(propName) {
+  return function (data) {
+    return data[propName];
+  };
+}
+
+module.exports = unique;
+function unique(propName, keyStore) {
+  keyStore = keyStore || new ES6Set();
+
+  var keyfn = stringify;
+  if (typeof propName === 'string') {
+    keyfn = prop(propName);
+  } else if (typeof propName === 'function') {
+    keyfn = propName;
+  }
+
+  return filter(function (data) {
+    var key = keyfn(data);
+
+    if (keyStore.has(key)) {
+      return false;
+    }
+
+    keyStore.add(key);
+    return true;
+  });
+}