Add integration test for annotating a singular file (#64)

This PR builds on top of the integration tests in #60 and adds a test
for annotating a single file:

`bundle exec annotaterb models app/models/test_default.rb`

Rakefile

@@ -15,4 +15,4 @@ end
 
 task spec: ["spec:unit", "spec:integration"]
 
-task default: :spec
+task default: ["spec:unit"]

spec/dummyapp/Gemfile

@@ -38,6 +38,8 @@ group :development do
   # Use console on exceptions pages [https://github.com/rails/web-console]
   gem "web-console"
 
+  gem "pry-byebug"
+
   # Add speed badges [https://github.com/MiniProfiler/rack-mini-profiler]
   # gem "rack-mini-profiler"
 

spec/integration/annotate_single_file_spec.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require "integration_spec_helper"
+
+RSpec.describe "Annotate a single file", type: "aruba" do
+  let(:models_dir) { "app/models" }
+  let(:command_timeout_seconds) { 10 }
+
+  before do
+    copy(Dir[File.join(aruba.config.root_directory, "spec/dummyapp/*")], aruba.config.home_directory)
+
+    # Unset the bundler context from running annotaterb integration specs.
+    #   This way, when `run_command("bundle exec annotaterb")` runs, it runs as if it's within the context of dummyapp.
+    unset_bundler_env_vars
+  end
+
+  let(:templates_dir) { File.join(aruba.config.root_directory, "spec/templates/#{ENV["DATABASE_ADAPTER"]}") }
+  let(:model_file) { "app/models/test_default.rb" }
+
+  it "annotates a single file" do
+    expected_test_default = read(File.join(templates_dir, "test_default.rb")).join("\n")
+    expected_test_null_false = read(File.join(templates_dir, "test_null_false.rb")).join("\n")
+
+    original_test_default = read(File.join(models_dir, "test_default.rb")).join("\n")
+    original_test_null_false = read(File.join(models_dir, "test_null_false.rb")).join("\n")
+
+    # Check that files have been copied over correctly
+    expect(expected_test_default).not_to eq(original_test_default)
+    expect(expected_test_null_false).not_to eq(original_test_null_false)
+
+    _cmd = run_command_and_stop("bundle exec annotaterb models #{model_file}", fail_on_error: true, exit_timeout: command_timeout_seconds)
+
+    annotated_test_default = read(File.join(models_dir, "test_default.rb")).join("\n")
+    annotated_test_null_false = read(File.join(models_dir, "test_null_false.rb")).join("\n")
+
+    expect(last_command_started).to be_successfully_executed
+    expect(annotated_test_default).to eq(expected_test_default)
+    expect(annotated_test_null_false).not_to eq(expected_test_null_false)
+  end
+end