test: use chai-subset

In order to make assertions easier to write and read.
See: https://www.chaijs.com/plugins/chai-subset/

Author: Kocal

package.json

@@ -62,6 +62,7 @@
     "babel-eslint": "^10.0.1",
     "chai": "^3.5.0",
     "chai-fs": "^1.0.0",
+    "chai-subset": "^1.6.0",
     "core-js": "^3.0.0",
     "eslint": "^5.15.2",
     "eslint-loader": "^2.1.2",

test/functional.js

@@ -11,6 +11,7 @@
 
 const chai = require('chai');
 chai.use(require('chai-fs'));
+chai.use(require('chai-subset'));
 const expect = chai.expect;
 const path = require('path');
 const testSetup = require('./helpers/setup');

yarn.lock

@@ -1757,6 +1757,11 @@ chai-fs@^1.0.0:
     bit-mask "0.0.2-alpha"
     readdir-enhanced "^1.4.0"
 
+chai-subset@^1.6.0:
+  version "1.6.0"
+  resolved "https://registry.yarnpkg.com/chai-subset/-/chai-subset-1.6.0.tgz#a5d0ca14e329a79596ed70058b6646bd6988cfe9"
+  integrity sha1-pdDKFOMpp5WW7XAFi2ZGvWmIz+k=
+
 chai@^3.5.0:
   version "3.5.0"
   resolved "https://registry.yarnpkg.com/chai/-/chai-3.5.0.tgz#4d02637b067fe958bdbfdd3a40ec56fef7373247"