Add Prevent erb_lint From Removing Opening Tags as a Ruby TIL

ruby/prevent-erb-lint-from-removing-opening-tags.md

@@ -0,0 +1,45 @@
+# Prevent erb_lint From Removing Opening Tags
+
+The [`erb_lint` gem](https://github.com/Shopify/erb_lint) is a tool from
+shopify for linting and auto-formatting ERB files. When I first set it up in a
+Rails codebase with the base `.erb-lint.yml` recommended in the README, I ran
+into a pernicious issue. The linter wanted to remove opening tags (i.e. `<%`
+and `<%=`) from my ERB files.
+
+So, for a file that looked like this:
+
+```erb
+<div>
+  <%= form_with(url: login_path, scope: :session) do |f| %>
+    <div>
+      <%= f.label :email %>
+      <%= f.email_field :email %>
+    </div>
+</div>
+```
+
+It would get formatted to this:
+
+```erb
+<div>
+form_with(url: login_path, scope: :session) do |f| %>
+    <div>
+f.label :email %>
+f.email_field :email %>
+    </div>
+</div>
+```
+
+Yikes!
+
+I had to disable a couple rules (under `rubocop_config:`) in the `.erb-lint.yml` file to get it to stop
+doing this.
+
+```yaml
+Layout/InitialIndentation:
+  Enabled: false
+Layout/TrailingEmptyLines:
+  Enabled: false
+```
+
+[source](https://github.com/Shopify/erb_lint/issues/222)