Add Stack Heredocs In A Method Call as a Ruby 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).
 
-_1516 TILs and counting..._
+_1517 TILs and counting..._
 
 ---
 
@@ -1294,6 +1294,7 @@ _1516 TILs and counting..._
 - [Specify How Random Array#sample Is](ruby/specify-how-random-array-sample-is.md)
 - [Split A Float Into Its Integer And Decimal](ruby/split-a-float-into-its-integer-and-decimal.md)
 - [Squeeze Out The Extra Space](ruby/squeeze-out-the-extra-space.md)
+- [Stack Heredocs In A Method Call](ruby/stack-heredocs-in-a-method-call.md)
 - [String Interpolation With Instance Variables](ruby/string-interpolation-with-instance-variables.md)
 - [Summing Collections](ruby/summing-collections.md)
 - [Triple Equals: The Case Equality Operator](ruby/triple-equals-the-case-equality-operator.md)

ruby/stack-heredocs-in-a-method-call.md

@@ -0,0 +1,37 @@
+# Stack Heredocs In A Method Call
+
+When you put a heredoc directly in a method call as an argument, it is only the
+opening identifier that goes in the argument list.
+
+That looks like this:
+
+```ruby
+execute_in_transaction(<<~SQL)
+  update reading_statuses
+  set status = 'abandoned'
+  where started_at < (now() - '2 years'::interval)
+    and finished_at is null;
+SQL
+```
+
+You might imagine then that we can put multiple heredocs in a method call. That
+leads to [_stacked
+heredocs_](https://www.visualmode.dev/ruby-operators/heredoc#stacked-heredocs).
+
+```ruby
+execute_in_transaction(<<~SQL1, <<~SQL2, <<~SQL3)
+  update reading_statuses
+  set status = 'abandoned'
+  where started_at < (now() - '2 years'::interval)
+    and finished_at is null;
+SQL1
+  insert into activity_log (name, description)
+  values ('abandon_books', 'Mark unread books as abandoned');
+SQL2
+  delete from background_jobs
+  where id = #{job_id}; -- better to sanitize values like this
+SQL3
+```
+
+Notice we terminate the body of each heredoc with its closing identifier and
+immediately begin the body of the next one.