[#94] Backend

https://project.mdnd-it.cc/work_packages/94

SerpentRace_Backend/node_modules/stream-chain/utils/skip.js

@@ -0,0 +1,32 @@
+'use strict';
+
+const {Transform} = require('stream');
+
+class Skip extends Transform {
+  constructor(options) {
+    super(Object.assign({}, options, {writableObjectMode: true, readableObjectMode: true}));
+    this._n = 0;
+    if (options) {
+      'n' in options && (this._n = options.n);
+    }
+    if (this._n <= 0) {
+      this._transform = this._passThrough;
+    }
+  }
+  _transform(chunk, encoding, callback) {
+    if (--this._n <= 0) {
+      this._transform = this._passThrough;
+    }
+    callback(null);
+  }
+  _passThrough(chunk, encoding, callback) {
+    this.push(chunk);
+    callback(null);
+  }
+  static make(n) {
+    return new Skip(typeof n == 'object' ? n : {n});
+  }
+}
+Skip.make.Constructor = Skip;
+
+module.exports = Skip.make;