Use Readline.readline for feature_flag binary

bin/feature-flag

@@ -9,6 +9,7 @@ require 'optparse'
 require 'yaml'
 require 'fileutils'
 require 'uri'
+require 'readline'
 
 require_relative '../lib/feature/shared' unless defined?(Feature::Shared)
 
@@ -114,8 +115,7 @@ class FeatureFlagOptionParser
       $stdout.puts ">> Specify the group introducing the feature flag, like `group::apm`:"
 
       loop do
-        $stdout.print "?> "
-        group = $stdin.gets.strip
+        group = Readline.readline('?> ', false)&.strip
         group = nil if group.empty?
         return group if group.nil? || group.start_with?('group::')
 
@@ -137,9 +137,7 @@ class FeatureFlagOptionParser
       end
 
       loop do
-        $stdout.print "?> "
-
-        type = $stdin.gets.strip.to_sym
+        type = Readline.readline('?> ', false)&.strip&.to_sym
         return type if TYPES[type] && !TYPES[type][:deprecated]
 
         $stderr.puts "Invalid type specified '#{type}'"
@@ -151,8 +149,7 @@ class FeatureFlagOptionParser
       $stdout.puts ">> URL of the MR introducing the feature flag (enter to skip):"
 
       loop do
-        $stdout.print "?> "
-        introduced_by_url = $stdin.gets.strip
+        introduced_by_url = Readline.readline('?> ', false)&.strip
         introduced_by_url = nil if introduced_by_url.empty?
         return introduced_by_url if introduced_by_url.nil? || introduced_by_url.start_with?('https://')
 
@@ -184,8 +181,7 @@ class FeatureFlagOptionParser
       $stdout.puts ">> URL of the rollout issue (enter to skip):"
 
       loop do
-        $stdout.print "?> "
-        created_url = $stdin.gets.strip
+        created_url = Readline.readline('?> ', false)&.strip
         created_url = nil if created_url.empty?
         return created_url if created_url.nil? || created_url.start_with?('https://')
 
@@ -218,7 +214,7 @@ class FeatureFlagCreator
     assert_name!
     assert_existing_feature_flag!
 
-    # Read type from $stdin unless is already set
+    # Read type from stdin unless is already set
     options.type ||= FeatureFlagOptionParser.read_type
     options.ee ||= FeatureFlagOptionParser.read_ee_only(options)
     options.group ||= FeatureFlagOptionParser.read_group

spec/bin/feature_flag_spec.rb

@@ -25,7 +25,7 @@ RSpec.describe 'bin/feature-flag' do
       allow(File).to receive(:write).and_return(true)
 
       # ignore stdin
-      allow($stdin).to receive(:gets).and_raise('EOF')
+      allow(Readline).to receive(:readline).and_raise('EOF')
     end
 
     subject { creator.execute }
@@ -135,8 +135,8 @@ RSpec.describe 'bin/feature-flag' do
           let(:type) { 'deprecated' }
 
           it 'shows error message and retries' do
-            expect($stdin).to receive(:gets).and_return(type)
-            expect($stdin).to receive(:gets).and_raise('EOF')
+            expect(Readline).to receive(:readline).and_return(type)
+            expect(Readline).to receive(:readline).and_raise('EOF')
 
             expect do
               expect { described_class.read_type }.to raise_error(/EOF/)
@@ -154,8 +154,8 @@ RSpec.describe 'bin/feature-flag' do
           )
         end
 
-        it 'reads type from $stdin' do
-          expect($stdin).to receive(:gets).and_return(type)
+        it 'reads type from stdin' do
+          expect(Readline).to receive(:readline).and_return(type)
           expect do
             expect(described_class.read_type).to eq(:development)
           end.to output(/Specify the feature flag type/).to_stdout
@@ -165,8 +165,8 @@ RSpec.describe 'bin/feature-flag' do
           let(:type) { 'invalid' }
 
           it 'shows error message and retries' do
-            expect($stdin).to receive(:gets).and_return(type)
-            expect($stdin).to receive(:gets).and_raise('EOF')
+            expect(Readline).to receive(:readline).and_return(type)
+            expect(Readline).to receive(:readline).and_raise('EOF')
 
             expect do
               expect { described_class.read_type }.to raise_error(/EOF/)
@@ -180,8 +180,8 @@ RSpec.describe 'bin/feature-flag' do
     describe '.read_group' do
       let(:group) { 'group::memory' }
 
-      it 'reads type from $stdin' do
-        expect($stdin).to receive(:gets).and_return(group)
+      it 'reads type from stdin' do
+        expect(Readline).to receive(:readline).and_return(group)
         expect do
           expect(described_class.read_group).to eq('group::memory')
         end.to output(/Specify the group introducing the feature flag/).to_stdout
@@ -191,8 +191,8 @@ RSpec.describe 'bin/feature-flag' do
         let(:type) { 'invalid' }
 
         it 'shows error message and retries' do
-          expect($stdin).to receive(:gets).and_return(type)
-          expect($stdin).to receive(:gets).and_raise('EOF')
+          expect(Readline).to receive(:readline).and_return(type)
+          expect(Readline).to receive(:readline).and_raise('EOF')
 
           expect do
             expect { described_class.read_group }.to raise_error(/EOF/)
@@ -205,8 +205,8 @@ RSpec.describe 'bin/feature-flag' do
     describe '.read_introduced_by_url' do
       let(:url) { 'https://merge-request' }
 
-      it 'reads type from $stdin' do
-        expect($stdin).to receive(:gets).and_return(url)
+      it 'reads type from stdin' do
+        expect(Readline).to receive(:readline).and_return(url)
         expect do
           expect(described_class.read_introduced_by_url).to eq('https://merge-request')
         end.to output(/URL of the MR introducing the feature flag/).to_stdout
@@ -216,7 +216,7 @@ RSpec.describe 'bin/feature-flag' do
         let(:url) { '' }
 
         it 'skips entry' do
-          expect($stdin).to receive(:gets).and_return(url)
+          expect(Readline).to receive(:readline).and_return(url)
           expect do
             expect(described_class.read_introduced_by_url).to be_nil
           end.to output(/URL of the MR introducing the feature flag/).to_stdout
@@ -227,8 +227,8 @@ RSpec.describe 'bin/feature-flag' do
         let(:url) { 'invalid' }
 
         it 'shows error message and retries' do
-          expect($stdin).to receive(:gets).and_return(url)
-          expect($stdin).to receive(:gets).and_raise('EOF')
+          expect(Readline).to receive(:readline).and_return(url)
+          expect(Readline).to receive(:readline).and_raise('EOF')
 
           expect do
             expect { described_class.read_introduced_by_url }.to raise_error(/EOF/)
@@ -242,8 +242,8 @@ RSpec.describe 'bin/feature-flag' do
       let(:options) { double('options', name: 'foo', type: :development) }
       let(:url) { 'https://issue' }
 
-      it 'reads type from $stdin' do
-        expect($stdin).to receive(:gets).and_return(url)
+      it 'reads type from stdin' do
+        expect(Readline).to receive(:readline).and_return(url)
         expect do
           expect(described_class.read_rollout_issue_url(options)).to eq('https://issue')
         end.to output(/URL of the rollout issue/).to_stdout
@@ -253,8 +253,8 @@ RSpec.describe 'bin/feature-flag' do
         let(:type) { 'invalid' }
 
         it 'shows error message and retries' do
-          expect($stdin).to receive(:gets).and_return(type)
-          expect($stdin).to receive(:gets).and_raise('EOF')
+          expect(Readline).to receive(:readline).and_return(type)
+          expect(Readline).to receive(:readline).and_raise('EOF')
 
           expect do
             expect { described_class.read_rollout_issue_url(options) }.to raise_error(/EOF/)