replace jest with ava

node_modules/concordance/lib/hasLength.js

@@ -0,0 +1,15 @@
+'use strict'
+
+const isLength = require('lodash.islength')
+
+const hop = Object.prototype.hasOwnProperty
+
+function hasLength (obj) {
+  return (
+    Array.isArray(obj) ||
+    (hop.call(obj, 'length') &&
+      isLength(obj.length) &&
+      (obj.length === 0 || '0' in obj))
+  )
+}
+module.exports = hasLength