Add Use IRB And Ruby Flags With Rails Console as a Rails TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1214 TILs and counting..._
+_1215 TILs and counting..._
 
 ---
 
@@ -809,6 +809,7 @@ _1214 TILs and counting..._
 - [Truncate Almost All Tables](rails/truncate-almost-all-tables.md)
 - [Update Column Versus Update Attribute](rails/update-column-versus-update-attribute.md)
 - [Upgrading Your Manifest For Sprocket's 4](rails/upgrading-your-manifest-for-sprockets-4.md)
+- [Use IRB And Ruby Flags With Rails Console](rails/use-irb-and-ruby-flags-with-rails-console.md)
 - [Verify And Read A Signed Cookie Value](rails/verify-and-read-a-signed-cookie-value.md)
 - [Where Am I In The Partial Iteration?](rails/where-am-i-in-the-partial-iteration.md)
 - [Wipe Out All Precompiled Assets](rails/wipe-out-all-precompiled-assets.md)

rails/use-irb-and-ruby-flags-with-rails-console.md

@@ -0,0 +1,22 @@
+# Use IRB And Ruby Flags With Rails Console
+
+The `rails console` command only accepts two flags `--environment` and
+`--[no-]sandbox`. However, the `rails console` is built on top of IRB and Ruby,
+so it can accept flags that those commands understand.
+
+You can't pass an IRB flag directly to `rails console` though because it
+doesn't consider those part of its repertoire.
+
+```bash
+$ rails console --sandbox -r './vendor/setup_records.rb'
+```
+
+It will put the session in sandbox mode, but it doesn't know what to do with
+`-r`.  We have to explicitly separate its flags from flags that should be
+passed through. This is done with the `--` CLI convention.
+
+```bash
+$ rails console --sandbox -- -r './vendor/setup_records.rb'
+```
+
+Everything after the `--` gets passed along to IRB.