Add Parameterize A String With Underscores as a Rails TIL

rails/parameterize-a-string-with-underscores.md

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+# Parameterize A String With Underscores
+
+I have human-readable status strings that I'm working with like `In progress`,
+`Pending approval`, and `Completed`. I need to deterministically turn those
+into parameterized values that I can compare. That is, I want them lowercased
+and separated by underscores instead of spaces.
+
+The `ActiveSupport` `#parameterize` method, as is, gets me pretty close.
+
+```ruby
+> statuses = [
+  "In progress",
+  "Pending approval",
+  "Completed"
+]
+
+> statuses.map(&:parameterize)
+=> [
+  "in-progress",
+  "pending-approval",
+  "completed"
+]
+```
+
+Those are separated by dashes though. Fortunately, `parameterize` takes a
+`separator` option that we can use to verride what character is used to
+separate words. Let's use an underscore (`_`).
+
+```ruby
+> statuses.map { |str| str.parameterize(separator: '_') }
+=> [
+  "in_progress",
+  "pending_approval",
+  "completed"
+]
+```
+
+See the [`#paramterize`
+docs](https://api.rubyonrails.org/classes/ActiveSupport/Inflector.html#method-i-parameterize)
+for more details.