Merge pull request #6 from rainforestapp/RF-18143/pp/Lint-NoEnv-cop

[RF-18143] Port Lint/NoEnv cop from rf-stylez, fix it, make it autocorrect

.gitignore

@@ -10,3 +10,6 @@
 # rspec failure tracking
 .rspec_status
 Gemfile.lock
+
+# editors
+.vscode/

Gemfile.lock

@@ -1,13 +1,20 @@
 PATH
   remote: .
   specs:
-    get_env (0.1.3)
+    get_env (0.2.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
+    ast (2.4.0)
     diff-lcs (1.3)
+    jaro_winkler (1.5.4)
+    parallel (1.19.1)
+    parser (2.7.1.2)
+      ast (~> 2.4.0)
+    rainbow (3.0.0)
     rake (13.0.1)
+    rexml (3.2.4)
     rspec (3.8.0)
       rspec-core (~> 3.8.0)
       rspec-expectations (~> 3.8.0)
@@ -23,6 +30,16 @@ GEM
     rspec-support (3.8.0)
     rspec_junit_formatter (0.4.1)
       rspec-core (>= 2, < 4, != 2.12.0)
+    rubocop (0.80.1)
+      jaro_winkler (~> 1.5.1)
+      parallel (~> 1.10)
+      parser (>= 2.7.0.1)
+      rainbow (>= 2.2.2, < 4.0)
+      rexml
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (>= 1.4.0, < 1.7)
+    ruby-progressbar (1.10.1)
+    unicode-display_width (1.6.1)
 
 PLATFORMS
   ruby
@@ -33,6 +50,7 @@ DEPENDENCIES
   rake
   rspec
   rspec_junit_formatter
+  rubocop
 
 BUNDLED WITH
    1.17.3

README.md

@@ -25,6 +25,19 @@ GetEnv['YOUR_ENV_VARIABLE']
 GetEnv.fetch('YOUR_ENV_VARIABLE') # Will raise a KeyError
 ```
 
+## Rubocop extension
+
+Add this to your `rubocop.yml`:
+```yaml
+require:
+  - get_env/cops
+
+Lint/NoENV:
+  Enabled: true
+```
+
+This will flag any instances of `ENV::[]` and `ENV::fetch` as Rubcop offenses.
+
 ## Development
 
 After checking out the repo run `rake spec` to run the tests.

get_env.gemspec

@@ -5,19 +5,28 @@ require 'get_env/version'
 Gem::Specification.new do |spec|
   spec.name          = 'get_env'
   spec.version       = GetEnv::VERSION
-  spec.authors       = ['Simon Mathieu', 'Bartek Kruszczynski', 'Jonathan Barber']
-  spec.email         = ['[email protected]', '[email protected]']
+  spec.authors       = [
+    'Simon Mathieu',
+    'Bartek Kruszczynski',
+    'Jonathan Barber',
+    'Paul Padier']
+  spec.email         = [
+    '[email protected]',
+    '[email protected]',
+    '[email protected]']
 
   spec.summary       = 'Read values from ENV in a reasonable way'
   spec.description   = 'Read values from ENV in a reasonable way'
   spec.homepage      = 'https://github.com/rainforestapp/get_env'
   spec.license       = 'MIT'
 
-  spec.files         = ['lib/get_env.rb', 'lib/get_env/version.rb']
+  spec.files         = Dir['lib/**/*']
+  spec.test_files    = Dir['spec/**/*']
   spec.require_paths = ['lib']
 
   spec.add_development_dependency 'bundler'
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rspec'
   spec.add_development_dependency 'rspec_junit_formatter'
+  spec.add_development_dependency 'rubocop'
 end

lib/get_env.rb

@@ -1,9 +1,11 @@
 # frozen_string_literal: true
-require "get_env/version"
+
+require 'get_env/version'
 
 module GetEnv
   def self.[](key)
     return nil if key.nil?
+
     v = ENV[key].to_i
     return v if v.to_s == ENV[key]
 
@@ -19,7 +21,7 @@ def self.[](key)
   def self.fetch(key, default = nil)
     if ENV.has_key?(key)
       self[key]
-    elsif default != nil
+    elsif !default.nil?
       default
     elsif block_given?
       yield

lib/get_env/cops.rb

@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+require_relative '../rubocop/cop/lint/no_env'

lib/get_env/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module GetEnv
-  VERSION = '0.1.4'
+  VERSION = '0.2.0'
 end

lib/rubocop/cop/lint/no_env.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Lint
+      # @example
+      #   # bad
+      #   ENV[]
+      #
+      #   # bad
+      #   ENV.fetch(..)
+      #
+      #   # good
+      #   GetEnv[]
+      #
+      #   # good
+      #   GetEnv.fetch(...)
+      class NoENV < Cop
+        MSG = 'Use `GetEnv` instead of `ENV`.'
+
+        def_node_matcher :is_ENV_index?, '(send (const nil? :ENV) :[] _key)'
+        def_node_matcher :is_ENV_fetch?, '(send (const nil? :ENV) :fetch _key ...)'
+
+        def on_const(node)
+          parent = node.parent
+          return unless is_ENV_index?(parent) || is_ENV_fetch?(parent)
+
+          add_offense(node)
+        end
+
+        def autocorrect(node)
+          lambda do |corrector|
+            if Gem::Version.new(RuboCop::Version.version) >= Gem::Version.new('0.82.0')
+              corrector.replace(node, 'GetEnv')
+            else
+              corrector.replace(node.loc.expression, 'GetEnv')
+            end
+          end
+        end
+      end
+    end
+  end
+end

spec/rubocop/cop/lint/no_env_spec.rb

@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+require 'rubocop'
+require 'rubocop/rspec/support'
+require_relative '../../../../lib/rubocop/cop/lint/no_env'
+
+RSpec.describe RuboCop::Cop::Lint::NoENV do
+  include RuboCop::RSpec::ExpectOffense
+
+  let(:config) { RuboCop::Config.new }
+
+  subject(:cop) { described_class.new(config) }
+
+  describe '#[]' do
+    it 'registers an offense when using `ENV`' do
+      expect_offense(<<~RUBY)
+        FOO = ENV['FOO']
+              ^^^ Use `GetEnv` instead of `ENV`.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        FOO = GetEnv['FOO']
+      RUBY
+    end
+
+    it 'does not register an offense when using `GetEnv`' do
+      expect_no_offenses(<<~RUBY)
+        FOO = GetEnv['FOO']
+      RUBY
+    end
+  end
+
+  describe '#fetch' do
+    it 'registers an offense when using `ENV`' do
+      expect_offense(<<~RUBY)
+        do_the_thing(ENV.fetch('FOO'))
+                     ^^^ Use `GetEnv` instead of `ENV`.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        do_the_thing(GetEnv.fetch('FOO'))
+      RUBY
+    end
+
+    it 'registers an offense when using `ENV` with a default value' do
+      expect_offense(<<~RUBY)
+        a = x + ENV.fetch('FOO', 42)
+                ^^^ Use `GetEnv` instead of `ENV`.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        a = x + GetEnv.fetch('FOO', 42)
+      RUBY
+    end
+
+    it 'does not register an offense when using `GetEnv`' do
+      expect_no_offenses(<<~RUBY)
+        do_the_thing(GetEnv.fetch('FOO'))
+      RUBY
+    end
+
+    it 'does not register an offense when using `GetEnv` with a default value' do
+      expect_no_offenses(<<~RUBY)
+        a = x + GetEnv.fetch('FOO', 42)
+      RUBY
+    end
+  end
+
+  it 'does not register an offense when using `ENV` for a method not defined by `GetEnv`' do
+    expect_no_offenses(<<~RUBY)
+      ENV.map do |var|
+        foo << var.lowercase
+      end
+    RUBY
+  end
+end