Implement `file_match' condition keyword

spec/producer/core/tests/file_match_spec.rb

@@ -0,0 +1,46 @@
+require 'spec_helper'
+
+module Producer::Core
+  module Tests
+    describe FileMatch, :env do
+      let(:filepath)  { 'some_file' }
+      let(:pattern)   { /\Asome_content\z/ }
+      subject(:test)  { described_class.new(env, filepath, pattern) }
+
+      it_behaves_like 'test'
+
+      describe '#verify' do
+        context 'when file matches the pattern' do
+          before do
+            allow(remote_fs)
+              .to receive(:file_read).with(filepath) { 'some_content' }
+          end
+
+          it 'returns true' do
+            expect(test.verify).to be true
+          end
+        end
+
+        context 'when file does not match the pattern' do
+          before do
+            allow(remote_fs).to receive(:file_read).with(filepath) { 'foo bar' }
+          end
+
+          it 'returns false' do
+            expect(test.verify).to be false
+          end
+        end
+
+        context 'when file does not exist' do
+          before do
+            allow(remote_fs).to receive(:file_read).with(filepath) { nil }
+          end
+
+          it 'returns false' do
+            expect(test.verify).to be false
+          end
+        end
+      end
+    end
+  end
+end