Add spec for exception when failure_lines has a bad encoding

Author: bf4

spec/rspec/core/encoding_spec.rb

@@ -0,0 +1,47 @@
+# # encoding: utf-8
+require 'spec_helper'
+require 'rspec/core/notifications'
+
+RSpec.describe "FailedExampleNotification" do
+  break unless String.method_defined?(:encoding)
+
+  include FormatterSupport
+
+  let(:notification) { ::RSpec::Core::Notifications::FailedExampleNotification.new(example) }
+
+  before do
+    allow(example).to receive(:file_path) { __FILE__ }
+  end
+
+  describe '#message_lines' do
+    let(:message_with_invalid_byte_sequence) do
+      "\xEF \255 \xAD".force_encoding(Encoding::UTF_8)
+    end
+    let(:exception) do
+      instance_double(
+        Exception,
+        :backtrace => [ "#{__FILE__}:#{__LINE__}"],
+        :message => message_with_invalid_byte_sequence,
+      )
+    end
+    let(:example_group) do
+      class_double(
+        RSpec::Core::ExampleGroup,
+        :metadata => {},
+        :parent_groups => [],
+        :location => "#{__FILE__}:#{__LINE__}"
+      )
+    end
+
+    before do
+      allow(example).to receive(:example_group) { example_group }
+    end
+
+    context "when failure_lines contains an invalid byte sequence" do
+      it "raises an ArgumentError" do
+        expect { lines = notification.message_lines }.to raise_error(ArgumentError)
+      end
+    end
+
+  end
+end