Add property based tests to assess load reverses dump

package.json

@@ -36,6 +36,7 @@
     "browserify": "^14.3.0",
     "codemirror": "^5.13.4",
     "eslint": "^4.1.1",
+    "fast-check": "0.0.13",
     "istanbul": "^0.4.5",
     "mocha": "^3.3.0",
     "uglify-js": "^3.0.1"

test/25-dumper-fuzzy.js

@@ -0,0 +1,47 @@
+'use strict';
+
+var assert = require('assert');
+var fc     = require('fast-check');
+var yaml   = require('../');
+
+// Generate valid YAML instances for yaml.safeDump
+var key = fc.string16bits();
+var values = [
+  key, fc.boolean(), fc.integer(), fc.double(),
+  fc.constantFrom(null, Number.NEGATIVE_INFINITY, Number.POSITIVE_INFINITY)
+];
+var yamlArbitrary = fc.object({ key: key, values: values });
+
+// Generate valid options for yaml.safeDump configuration
+var dumpOptionsArbitrary = fc.record({
+  skipInvalid: fc.boolean(),
+  sortKeys: fc.boolean(),
+  noRefs: fc.boolean(),
+  noCompatMode: fc.boolean(),
+  condenseFlow: fc.boolean(),
+  indent: fc.integer(1, 80),
+  flowLevel: fc.integer(-1, 10),
+  styles: fc.record({
+    '!!null': fc.constantFrom('lowercase', 'canonical', 'uppercase', 'camelcase'),
+    '!!int': fc.constantFrom('decimal', 'binary', 'octal', 'hexadecimal'),
+    '!!bool': fc.constantFrom('lowercase', 'uppercase', 'camelcase'),
+    '!!float': fc.constantFrom('lowercase', 'uppercase', 'camelcase')
+  }, { with_deleted_keys: true })
+}, { with_deleted_keys: true })
+  .map(function (instance) {
+    if (instance.condenseFlow === true && instance.flowLevel !== undefined) { instance.flowLevel = -1; }
+    return instance;
+  });
+
+suite('Properties', function () {
+  test('Load from dumped should be the original object', function () {
+    fc.assert(fc.property(
+      yamlArbitrary,
+      dumpOptionsArbitrary,
+      function (obj, dumpOptions) {
+        var yamlContent = yaml.safeDump(obj, dumpOptions);
+        assert.ok(typeof yamlContent === 'string');
+        assert.deepStrictEqual(yaml.safeLoad(yamlContent), obj);
+      }));
+  });
+});