From c94076079b8377af004d09bd9daa7567db01a178 Mon Sep 17 00:00:00 2001
From: Tejas Bubane <tejasbubane@gmail.com>
Date: Mon, 8 Jul 2019 16:49:07 +0530
Subject: [PATCH] Add section for hash syntax of enums

Closes https://github.com/rubocop-hq/rails-style-guide/issues/144

Ref: https://github.com/rubocop-hq/rubocop-rails/issues/78
---
 README.adoc | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/README.adoc b/README.adoc
index c9080ffc..8a6e6fb3 100644
--- a/README.adoc
+++ b/README.adoc
@@ -385,6 +385,26 @@ class Transaction < ActiveRecord::Base
 end
 ----
 
+=== Enums [[enums]]
+
+Prefer using the hash syntax for `enum`. Array makes the database values implicit
+& any insertion/removal/rearrangement of values in the middle will most probably
+lead to broken code.
+
+[source,ruby]
+----
+class Transaction < ActiveRecord::Base
+  # bad - implicit values - ordering matters
+  enum type: %i[credit debit]
+
+  # good - explicit values - ordering does not matter
+  enum type: {
+    credit: 0,
+    debit: 1
+  }
+end
+----
+
 === Macro Style Methods [[macro-style-methods]]
 
 Group macro-style methods (`has_many`, `validates`, etc) in the beginning of the class definition.