extract renameStorage, removeStorage methods

and tests for each of them

browser/main/lib/dataApi/removeStorage.js

@@ -0,0 +1,28 @@
+const _ = require('lodash')
+
+/**
+ * @param {String} key
+ * @return {key}
+ */
+function removeStorage (key) {
+  let rawStorages
+
+  try {
+    rawStorages = JSON.parse(localStorage.getItem('storages'))
+    if (!_.isArray(rawStorages)) throw new Error('invalid storages')
+  } catch (e) {
+    console.warn(e)
+    rawStorages = []
+  }
+
+  rawStorages = rawStorages
+    .filter(function excludeTargetStorage (rawStorage) {
+      return rawStorage.key !== key
+    })
+
+  localStorage.setItem('storages', JSON.stringify(rawStorages))
+
+  return Promise.resolve(key)
+}
+
+module.exports = removeStorage