Add Make A String Attribute Easy To Inquire About 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).
 
-_1332 TILs and counting..._
+_1334 TILs and counting..._
 
 ---
 
@@ -492,6 +492,7 @@ _1332 TILs and counting..._
 
 ### jq
 
+- [Combine An Array Of Objects Into A Single Object](jq/combine-an-array-of-objects-into-a-single-object.md)
 - [Count Each Collection In A JSON Object](jq/count-each-collection-in-a-json-object.md)
 - [Count The Number Of Things In A JSON File](jq/count-the-number-of-things-in-a-json-file.md)
 - [Extract A List Of Values](jq/extract-a-list-of-values.md)
@@ -839,6 +840,7 @@ _1332 TILs and counting..._
 - [Load Records In Batches With find_each](rails/load-records-in-batches-with-find-each.md)
 - [Log SQL Queries Executed By ActiveRecord](rails/log-sql-queries-executed-by-activerecord.md)
 - [Mark A Migration As Irreversible](rails/mark-a-migration-as-irreversible.md)
+- [Make A String Attribute Easy To Inquire About](rails/make-a-string-attribute-easy-to-inquire-about.md)
 - [Make ActionMailer Synchronous In Test](rails/make-action-mailer-synchronous-in-test.md)
 - [Make Remove Column Migration Reversible](rails/make-remove-column-migration-reversible.md)
 - [Manually Run A Migration From Rails Console](rails/manually-run-a-migration-from-rails-console.md)

jq/combine-an-array-of-objects-into-a-single-object.md

@@ -0,0 +1,40 @@
+# Combine An Array Of Objects Into A Single Object
+
+If you've spent any amount of time pulling data out of a JSON file with `jq`,
+you may have run into a result set that looks a little too spacious. It's this
+array of single key-value pair objects.
+
+```bash
+$ jq '.items | map({(.slug)}: .amount})' my-data.json
+
+[
+  {
+    "key-1": 123
+  },
+  {
+    "key-2": 345
+  },
+  {
+    "key-3": 456
+  },
+  ...
+]
+```
+
+When what you really wanted was a single object full of those unique key-value
+pairs.
+
+That query has you 90% of the way there. The trick is to pipe that array
+through the [`add` function](https://jqlang.github.io/jq/manual/#add) which
+will combine each of those individual objects into a single object.
+
+```bash
+$ jq '.items | map({(.slug)}: .amount}) | add' my-data.json
+
+{
+  "key-1": 123,
+  "key-2": 345,
+  "key-3": 456,
+  ...
+}
+```

rails/make-a-string-attribute-easy-to-inquire-about.md

@@ -0,0 +1,49 @@
+# Make A String Attribute Easy to Inquire About
+
+Have you ever been curious why Rails environment checks work the way they do?
+
+```ruby
+> Rails.env
+#=> 'development'
+> Rails.env.development?
+#=> true
+```
+
+What is powering this is
+[`ActiveSupport::StringInquirer`](https://api.rubyonrails.org/classes/ActiveSupport/StringInquirer.html).
+And since it is part of `ActiveSupport`, you can use that functionality
+elsewhere in your Rails code.
+
+Let's look at an example:
+
+```ruby
+class UserWithRole
+  attr_reader :name, :role
+
+  def initialize(name, role)
+    @name = name
+    @role = ActiveSupport::StringInquirer.new(role)
+  end
+end
+```
+
+With that class defined, we can initialize a user and inquire about their role.
+
+```ruby
+> user = UserWithRole.new('Bob', 'instructor')
+#=> <UserWithRole ...>
+> user.role.instructor?
+#=> true
+> user.role.admin?
+#=> false
+> user.role
+#=> 'instructor'
+```
+
+This helper class makes it much cleaner to inquire about the role of a user.
+Notice we don't have to do a string comparison to check if they are an
+instructor, e.g.:
+
+```ruby
+> user.role == 'instructor'
+```