Add step and API to add whole lines to a file

.rubocop.yml

@@ -11,6 +11,12 @@ AllCops:
   NewCops: enable
   TargetRubyVersion: 2.4
 
+# Spec blocks can be any size
+Metrics/BlockLength:
+  Exclude:
+    - '**/*.gemspec'
+    - 'spec/**/*'
+
 # Use older RuboCop default
 Style/PercentLiteralDelimiters:
   PreferredDelimiters:

.rubocop_todo.yml

@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config --no-offense-counts --no-auto-gen-timestamp`
-# using RuboCop version 1.6.1.
+# using RuboCop version 1.8.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -40,7 +40,7 @@ Metrics/AbcSize:
 # Configuration parameters: CountComments, CountAsOne, ExcludedMethods, IgnoredMethods.
 # IgnoredMethods: refine
 Metrics/BlockLength:
-  Max: 594
+  Max: 68
 
 # Configuration parameters: CountComments, CountAsOne.
 Metrics/ClassLength:
@@ -56,7 +56,7 @@ Metrics/MethodLength:
 
 # Configuration parameters: CountComments, CountAsOne.
 Metrics/ModuleLength:
-  Max: 182
+  Max: 193
 
 # Configuration parameters: IgnoredMethods.
 Metrics/PerceivedComplexity:

features/03_testing_frameworks/cucumber/steps/filesystem/append_to_file.feature

@@ -5,8 +5,8 @@ Feature: Append content to file
   Background:
     Given I use a fixture named "cli-app"
 
-  Scenario: Append to a existing file
-    Given a file named "features/non-existence.feature" with:
+  Scenario: Append to an existing file
+    Given a file named "features/appending.feature" with:
     """
     Feature: Existence
       Scenario: Existence
@@ -26,6 +26,28 @@ Feature: Append content to file
     When I run `cucumber`
     Then the features should all pass
 
+  Scenario: Append whole lines to an existing file
+    Given a file named "features/appending.feature" with:
+    """
+    Feature: Existence
+      Scenario: Existence
+        Given a file named "foo/bar/example.txt" with:
+        \"\"\"
+        hello world
+        \"\"\"
+        When I append the following lines to "foo/bar/example.txt":
+        \"\"\"
+        this was appended
+        \"\"\"
+        Then the file named "foo/bar/example.txt" should contain:
+        \"\"\"
+        hello world
+        this was appended
+        \"\"\"
+    """
+    When I run `cucumber`
+    Then the features should all pass
+
   Scenario: Append to a non-existing file
     Given a file named "features/non-existence.feature" with:
     """

lib/aruba/api/filesystem.rb

@@ -330,6 +330,28 @@ def append_to_file(file_name, file_content)
         File.open(file_name, "a") { |f| f << file_content }
       end
 
+      # Append lines to a (text) file. This will make sure a newline is present
+      # between the old content and the new.
+      #
+      # @param [String] file_name
+      #   The name of the file to be used
+      #
+      # @param [String] file_content
+      #   The lines which should be appended to file
+      def append_lines_to_file(file_name, file_content)
+        file_name = expand_path(file_name)
+
+        last = File.open(file_name) do |f|
+          f.seek(-3, IO::SEEK_END)
+          f.read
+        end
+
+        File.open(file_name, "a") do |f|
+          f << "\n" unless last.end_with? "\n"
+          f << file_content
+        end
+      end
+
       # Create a directory in current directory
       #
       # @param [String] directory_name

lib/aruba/cucumber/file.rb

@@ -68,6 +68,10 @@
   append_to_file(file_name, file_content)
 end
 
+When(/^I append the following lines to "([^"]*)":$/) do |file_name, file_content|
+  append_lines_to_file(file_name, file_content)
+end
+
 When(/^I append to "([^"]*)" with "([^"]*)"$/) do |file_name, file_content|
   append_to_file(file_name, file_content)
 end

spec/aruba/api/filesystem_spec.rb

@@ -4,6 +4,23 @@
 RSpec.describe Aruba::Api::Filesystem do
   include_context "uses aruba API"
 
+  describe "#append_lines_to_file" do
+    let(:path) { @file_path }
+    let(:name) { @file_name }
+
+    it "inserts a newline if existing file does not end in one" do
+      Aruba.platform.write_file(path, "foo\nbar")
+      append_lines_to_file(name, "baz")
+      expect(File.read(path)).to eq "foo\nbar\nbaz"
+    end
+
+    it "does not insert a newline if the existing file ends in one" do
+      Aruba.platform.write_file(path, "foo\nbar\n")
+      append_lines_to_file(name, "baz")
+      expect(File.read(path)).to eq "foo\nbar\nbaz"
+    end
+  end
+
   describe "#all_paths" do
     let(:name) { @file_name }
     let(:path) { @file_path }