initial commit.

node_modules/json2csv/lib/JSON2CSVAsyncParser.js

@@ -0,0 +1,60 @@
+'use strict';
+
+const { Transform } = require('stream');
+const JSON2CSVTransform = require('./JSON2CSVTransform');
+const { fastJoin } = require('./utils');
+
+class JSON2CSVAsyncParser {
+  constructor(opts, transformOpts) {
+    this.input = new Transform(transformOpts);
+    this.input._read = () => {};
+
+    this.transform = new JSON2CSVTransform(opts, transformOpts);
+    this.processor = this.input.pipe(this.transform);
+  }
+
+  fromInput(input) {
+    if (this._input) {
+      throw new Error('Async parser already has an input.');
+    }
+    this._input = input;
+    this.input = this._input.pipe(this.processor);
+    return this;
+  }
+
+  throughTransform(transform) {
+    if (this._output) {
+      throw new Error('Can\'t add transforms once an output has been added.');
+    }
+    this.processor = this.processor.pipe(transform);
+    return this;
+  }
+
+  toOutput(output) {
+    if (this._output) {
+      throw new Error('Async parser already has an output.');
+    }
+    this._output = output;
+    this.processor = this.processor.pipe(output);
+    return this;
+  }
+
+  promise(returnCSV = true) {
+    return new Promise((resolve, reject) => {
+      if (!returnCSV) {
+        this.processor
+          .on('finish', () => resolve())
+          .on('error', err => reject(err));
+        return;
+      }
+
+      let csvBuffer = [];
+      this.processor
+        .on('data', chunk => csvBuffer.push(chunk.toString()))
+        .on('finish', () => resolve(fastJoin(csvBuffer, '')))
+        .on('error', err => reject(err));
+    });
+  }
+}
+
+module.exports = JSON2CSVAsyncParser