Merge pull request #3083 from MetaMask/i3076-UseStorageLocalInstead

Use storage.local instead of localStorage

1 files changed, 38 insertions, 0 deletions

diff --git a/app/scripts/lib/local-store.js b/app/scripts/lib/local-store.js
new file mode 100644
index 000000000..781aea17e
--- /dev/null
+++ b/app/scripts/lib/local-store.js
@@ -0,0 +1,38 @@
+// We should not rely on local storage in an extension!
+// We should use this instead!
+// https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/storage/local
+
+const extension = require('extensionizer')
+const { promisify } = require('util').promisify
+
+module.exports = class ExtensionStore {
+  constructor() {
+    this.isSupported = !!(extension.storage.local)
+    if (!this.isSupported) {
+      log.error('Storage local API not available.')
+    }
+    const local = extension.storage.local
+    this._get = promisify(local.get).bind(local)
+    this._set = promisify(local.set).bind(local)
+  }
+
+  async get() {
+    if (!this.isSupported) return undefined
+    const result = await this._get()
+    // extension.storage.local always returns an obj
+    // if the object is empty, treat it as undefined
+    if (isEmpty(result)) {
+      return undefined
+    } else {
+      return result
+    }
+  }
+
+  async set(state) {
+    return this._set(state)
+  }
+}
+
+function isEmpty(obj) {
+  return Object.keys(obj).length === 0
+}