Add unit tests for role middleware

node_modules/formidable/src/plugins/json.js

@@ -0,0 +1,39 @@
+/* eslint-disable no-underscore-dangle */
+
+import JSONParser from '../parsers/JSON.js';
+
+export const jsonType = 'json';
+// the `options` is also available through the `this.options` / `formidable.options`
+export default function plugin(formidable, options) {
+  // the `this` context is always formidable, as the first argument of a plugin
+  // but this allows us to customize/test each plugin
+
+  /* istanbul ignore next */
+  const self = this || formidable;
+
+  if (/json/i.test(self.headers['content-type'])) {
+    init.call(self, self, options);
+  }
+
+  return self;
+};
+
+// Note that it's a good practice (but it's up to you) to use the `this.options` instead
+// of the passed `options` (second) param, because when you decide
+// to test the plugin you can pass custom `this` context to it (and so `this.options`)
+function init(_self, _opts) {
+  this.type = jsonType;
+
+  const parser = new JSONParser(this.options);
+
+  parser.on('data', (fields) => {
+    this.fields = fields;
+  });
+
+  parser.once('end', () => {
+    this.ended = true;
+    this._maybeEnd();
+  });
+
+  this._parser = parser;
+}