Implement `file_contains' condition keyword

features/steps/remote_steps.rb

@@ -6,6 +6,10 @@ Given /^a remote file named "([^"]+)"$/ do |file_name|
   write_file file_name, ''
 end
 
+Given /^a remote file named "([^"]+)" with "([^"]+)"$/ do |file_name, content|
+  write_file file_name, content
+end
+
 Then /^the remote directory "([^"]+)" should exists$/ do |path|
   check_directory_presence([path], true)
 end

features/tests/file_contains.feature

@@ -0,0 +1,28 @@
+@sshd
+Feature: `file_contains' condition keyword
+
+  Background:
+    Given a recipe with:
+      """
+      target 'some_host.test'
+
+      task :testing_content_in_file_presense do
+        condition { file_contains 'some_file', 'some_content' }
+
+        echo 'evaluated'
+      end
+      """
+
+  Scenario: succeeds when file contains expected content
+    Given a remote file named "some_file" with "some_content"
+    When I successfully execute the recipe
+    Then the output must contain "evaluated"
+
+  Scenario: fails when file does not contain expected content
+    Given a remote file named "some_file" with "some_other_content"
+    When I successfully execute the recipe
+    Then the output must not contain "evaluated"
+
+  Scenario: fails when file does not exist
+    When I successfully execute the recipe
+    Then the output must not contain "evaluated"