Create sqlite3 directory if not present

If the `db/` directory is not present on a remote machine it will blow up in unexpected ways with error messages that do not indicate there is a missing directory:

```
SQLite3::CantOpenException: unable to open database file
```

This PR checks to see if a directory exists for the sqlite3 file and if not creates it for you.

This PR is an alternative to #11692 as suggested by @josevalim

1 files changed, 21 insertions, 0 deletions

diff --git a/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb b/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb
new file mode 100644
index 0000000000..5a4fe63580
--- /dev/null
+++ b/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb
@@ -0,0 +1,21 @@
+# encoding: utf-8
+require "cases/helper"
+require 'models/owner'
+
+module ActiveRecord
+  module ConnectionAdapters
+    class SQLite3CreateFolder < ActiveRecord::TestCase
+      def test_sqlite_creates_directory
+        Dir.mktmpdir do |dir|
+          dir = Pathname.new(dir)
+          @conn = Base.sqlite3_connection :database => dir.join("db/foo.sqlite3"),
+                               :adapter => 'sqlite3',
+                               :timeout => 100
+
+          assert Dir.exists? dir.join('db')
+          assert File.exist? dir.join('db/foo.sqlite3')
+        end
+      end
+    end
+  end
+end