Add latest changes from gitlab-org/gitlab@master

1 files changed, 77 insertions, 0 deletions

diff --git a/spec/rubocop/cop/performance/readlines_each_spec.rb b/spec/rubocop/cop/performance/readlines_each_spec.rb
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+++ b/spec/rubocop/cop/performance/readlines_each_spec.rb
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+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+require_relative '../../../support/helpers/expect_offense'
+require_relative '../../../../rubocop/cop/performance/readlines_each'
+
+describe RuboCop::Cop::Performance::ReadlinesEach do
+  include CopHelper
+  include ExpectOffense
+
+  subject(:cop) { described_class.new }
+
+  let(:message) { 'Avoid `IO.readlines.each`, since it reads contents into memory in full. Use `IO.each_line` or `IO.each` instead.' }
+
+  shared_examples_for(:class_read) do |klass|
+    context "and it is called as a class method on #{klass}" do
+      # We can't use `expect_offense` here because indentation changes based on `klass`
+      it 'flags it as an offense' do
+        inspect_source "#{klass}.readlines(file_path).each { |line| puts line }"
+
+        expect(cop.offenses.map(&:cop_name)).to contain_exactly('Performance/ReadlinesEach')
+      end
+    end
+
+    context 'when just using readlines without each' do
+      it 'does not flag it as an offense' do
+        expect_no_offenses "contents = #{klass}.readlines(file_path)"
+      end
+    end
+  end
+
+  context 'when reading all lines using IO.readlines.each' do
+    %w(IO File).each do |klass|
+      it_behaves_like(:class_read, klass)
+    end
+
+    context 'and it is called as an instance method on a return value' do
+      it 'flags it as an offense' do
+        expect_offense <<~SOURCE
+          get_file.readlines.each { |line| puts line }
+                             ^^^^ #{message}
+        SOURCE
+      end
+    end
+
+    context 'and it is called as an instance method on an assigned variable' do
+      it 'flags it as an offense' do
+        expect_offense <<~SOURCE
+          file = File.new(path)
+          file.readlines.each { |line| puts line }
+                         ^^^^ #{message}
+        SOURCE
+      end
+    end
+
+    context 'and it is called as an instance method on a new object' do
+      it 'flags it as an offense' do
+        expect_offense <<~SOURCE
+          File.new(path).readlines.each { |line| puts line }
+                                   ^^^^ #{message}
+        SOURCE
+      end
+    end
+
+    it 'autocorrects `readlines.each` to `each_line`' do
+      expect(autocorrect_source('obj.readlines.each { |line| line }')).to(
+        eq('obj.each_line { |line| line }')
+      )
+    end
+  end
+
+  context 'when just using readlines without each' do
+    it 'does not flag it as an offense' do
+      expect_no_offenses 'contents = my_file.readlines'
+    end
+  end
+end