From d4f2ac06d28a6688b36d16458b48cc6503956cfe Mon Sep 17 00:00:00 2001
From: Dan Allen <dan.j.allen@gmail.com>
Date: Thu, 12 Oct 2023 02:29:19 -0600
Subject: [PATCH] capture and assert warning in test suite

---
 spec/lib/docbookrx/docbookrx_spec.rb |  8 +++++---
 spec/support/extensions/helpers.rb   | 15 +++++++++++++++
 2 files changed, 20 insertions(+), 3 deletions(-)
 create mode 100644 spec/support/extensions/helpers.rb

diff --git a/spec/lib/docbookrx/docbookrx_spec.rb b/spec/lib/docbookrx/docbookrx_spec.rb
index 5e701fa..b8545fd 100644
--- a/spec/lib/docbookrx/docbookrx_spec.rb
+++ b/spec/lib/docbookrx/docbookrx_spec.rb
@@ -474,9 +474,11 @@
 | Dam
 |===
     EOS
-    output = Docbookrx.convert input
-
-    expect(output).to include(expected)
+    capture_stdio do |_, stderr|
+      output = Docbookrx.convert input
+      expect(output).to include(expected)
+      expect(stderr.string).to include('5 columns specified in table \'Control parameters\', but only 4 headers')
+    end
   end
 
   it 'should convert nested program listings in listitems correctly' do
diff --git a/spec/support/extensions/helpers.rb b/spec/support/extensions/helpers.rb
new file mode 100644
index 0000000..6979961
--- /dev/null
+++ b/spec/support/extensions/helpers.rb
@@ -0,0 +1,15 @@
+require 'stringio'
+
+module RSpec::Support::Helpers
+  def capture_stdio
+    old_stdout, $stdout = $stdout, StringIO.new
+    old_stderr, $stderr = $stderr, StringIO.new
+    yield $stdout, $stderr
+  ensure
+    $stdout, $stderr = old_stdout, old_stderr
+  end
+end
+
+RSpec.configure do |config|
+  config.include RSpec::Support::Helpers
+end