Add identity synchronizing code

Addresses #4475, where entries in the identities object do not
necessarily have corresponding accounts in the vault.

On password submission, this change passes known accounts to the
preferencesController (responsible for nickname management), and removes
unknown entries.

Includes "TODO" notes for where we could log the issue to sentry or
notify the user.

1 files changed, 31 insertions, 0 deletions

diff --git a/app/scripts/controllers/preferences.js b/app/scripts/controllers/preferences.js
index 760868ddf..426ee5a02 100644
--- a/app/scripts/controllers/preferences.js
+++ b/app/scripts/controllers/preferences.js
@@ -98,6 +98,37 @@ class PreferencesController {
     this.store.updateState({ identities })
   }
 
+  /*
+   * Synchronizes identity entries with known accounts.
+   * Removes any unknown identities, and returns the resulting selected address.
+   *
+   * @param {Array<string>} addresses known to the vault.
+   * @returns {Promise<string>} selectedAddress the selected address.
+   */
+  syncAddresses (addresses) {
+    const identities = this.store.getState().identities
+
+    Object.keys(identities).forEach((identity) => {
+      if (!addresses.includes(identity)) {
+        delete identities[identity]
+
+        // TODO: Report the bug to Sentry including the now-lost identity.
+        // TODO: Inform the user of the lost identity.
+      }
+    })
+
+    this.store.updateState({ identities })
+    this.addAddresses(addresses)
+
+    let selected = this.getSelectedAddress()
+    if (!addresses.includes(selected)) {
+      selected = addresses[0]
+      this.setSelectedAddress(selected)
+    }
+
+    return selected
+  }
+
   /**
    * Setter for the `selectedAddress` property
    *