chore: collect test code coverage

Gemfile

@@ -3,7 +3,7 @@ source "https://rubygems.org"
 # Specify your gem's dependencies in activerecord-spanner.gemspec
 gemspec
 
-ar_version = ENV.fetch("AR_VERSION", "~> 7.1.0")
+ar_version = ENV.fetch("AR_VERSION", "~> 7.2.0")
 gem "activerecord", ar_version
 gem "ostruct"
 gem "minitest", "~> 5.25.0"
@@ -17,6 +17,7 @@ gem 'sqlite3'
 install_if -> { ar_version.dup.to_s.sub("~>", "").strip < "7.1.0" && !ENV["SKIP_COMPOSITE_PK"] } do
   gem "composite_primary_keys"
 end
+gem 'simplecov', require: false, group: :test
 
 # Required for samples
 gem "docker-api"

acceptance/test_helper.rb

@@ -4,6 +4,14 @@
 # license that can be found in the LICENSE file or at
 # https://opensource.org/licenses/MIT.
 
+require 'simplecov'
+SimpleCov.start do
+  add_filter '/test/'
+  add_filter '/acceptance/'
+  add_filter '/benchmarks/'
+end
+
+# Previous content of test helper now starts here
 gem "minitest"
 require "minitest/autorun"
 require "minitest/focus"

test/test_helper.rb

@@ -4,6 +4,13 @@
 # license that can be found in the LICENSE file or at
 # https://opensource.org/licenses/MIT.
 
+require 'simplecov'
+SimpleCov.start do
+  add_filter '/test/'
+  add_filter '/acceptance/'
+  add_filter '/benchmarks/'
+end
+
 require "minitest/autorun"
 require "minitest/focus"
 require "minitest/rg"