Initial upgrade plugin

plugins/upgrade/init.zsh

@@ -0,0 +1,43 @@
+# ------------------------------------------------------------------------------
+#          FILE:  upgrade-oh-my-zsh.plugin.zsh
+#   DESCRIPTION:  oh-my-zsh plugin file.
+#        AUTHOR:  Jonathan Dahan <jonathan@jedahan.com>
+#       VERSION:  0.3.0
+# ------------------------------------------------------------------------------
+
+# This plugin adds upgrade_zsh(), a relatively safe manual upgrade.
+# It also has two dangerous options that are off by default.
+#
+# zstyle ':omz:plugin:upgrade' auto-commit 'yes'
+#   auto-commit will commit whatever upstream changes there are without review
+#   This will still favor local changes when conflict arive
+#
+# zstyle ':omz:plugin:upgrade' auto-upgrade 'yes'
+#   auto-upgrade will check for updates 6 hours from the last successful upgrade
+
+function upgrade_zsh() {
+  current_path=`pwd`
+  cd ~/.oh-my-zsh
+
+  zstyle -t ':omz:plugin:upgrade' auto-commit || nocommit='--no-commit'
+
+  if git pull $nocommit --strategy=recursive -X ours origin master; then
+    printf '\033[0;34m%s\033[0m\n' 'Hooray! oh-my-zsh is up-to-date :)'
+    touch ~/.zsh-upgrade
+  else
+    printf '\033[0;31m%s\033[0m\n' 'Oh no! There was an error upgrading oh-my-zsh :('
+  fi
+
+  cd $current_path
+}
+
+if zstyle -t ':omz:plugin:upgrade' auto-upgrade; then
+  if [ -f ~/.zsh-upgrade ]; then
+    # upgrade if ~/.zsh-update was modified over 6 hours ago
+    if [ ~/.zsh-upgrade(Nmh+6) ]; then
+      upgrade_zsh
+    fi
+  else
+    upgrade_zsh
+  fi
+fi