Apply rubocop suggestions.

lib/ptools.rb

@@ -90,7 +90,7 @@ def self.binary?(file)
   #   File.which('ruby') # => '/usr/local/bin/ruby'
   #   File.which('foo')  # => nil
   #
-  def self.which(program, path = ENV['PATH'])
+  def self.which(program, path = ENV.fetch('PATH', nil))
     raise ArgumentError, 'path cannot be empty' if path.nil? || path.empty?
 
     # Bail out early if an absolute path is provided.
@@ -143,7 +143,7 @@ def self.which(program, path = ENV['PATH'])
   #   File.whereis('ruby') # => ['/usr/bin/ruby', '/usr/local/bin/ruby']
   #   File.whereis('foo')  # => nil
   #
-  def self.whereis(program, path = ENV['PATH'])
+  def self.whereis(program, path = ENV.fetch('PATH', nil))
     raise ArgumentError, 'path cannot be empty' if path.nil? || path.empty?
 
     paths = []
@@ -423,7 +423,7 @@ def self.nl_for_platform(platform)
   #
   def self.bmp?(file)
     data = File.read(file, 6, nil, :encoding => 'binary')
-    data[0,2] == 'BM' && File.size(file) == data[2,4].unpack('i').first
+    data[0, 2] == 'BM' && File.size(file) == data[2, 4].unpack1('i')
   end
 
   # Is the file a jpeg file?

spec/binary_spec.rb

@@ -10,7 +10,7 @@
 
 RSpec.describe File, :binary do
   let(:dirname)  { described_class.dirname(__FILE__) }
-  let(:bin_file) { File::ALT_SEPARATOR ? described_class.join(ENV['windir'], 'notepad.exe') : '/bin/ls' }
+  let(:bin_file) { File::ALT_SEPARATOR ? described_class.join(ENV.fetch('windir', nil), 'notepad.exe') : '/bin/ls' }
 
   before do
     @txt_file = described_class.join(dirname, 'txt', 'english.txt')

spec/head_spec.rb

@@ -29,7 +29,7 @@
   end
 
   example 'head method returns the expected results' do
-    expect(described_class.head(test_file)).to be_kind_of(Array)
+    expect(described_class.head(test_file)).to be_a(Array)
     expect(described_class.head(test_file)).to eq(@expected_head1)
     expect(described_class.head(test_file, 5)).to eq(@expected_head2)
   end

spec/tail_spec.rb

@@ -74,7 +74,7 @@
   end
 
   example 'tail returns the expected values' do
-    expect(described_class.tail(test_file1)).to be_kind_of(Array)
+    expect(described_class.tail(test_file1)).to be_a(Array)
     expect(described_class.tail(test_file1)).to eq(@expected_tail1)
     expect(described_class.tail(test_file1, 5)).to eq(@expected_tail2)
   end

spec/wc_spec.rb

@@ -35,7 +35,7 @@
   end
 
   example 'wc with no option returns expected results' do
-    expect(described_class.wc(test_file)).to be_kind_of(Array)
+    expect(described_class.wc(test_file)).to be_a(Array)
     expect(described_class.wc(test_file)).to eq([166, 166, 25, 25])
   end
 

spec/whereis_spec.rb

@@ -34,7 +34,7 @@
   example 'whereis basic functionality' do
     expect(described_class).to respond_to(:whereis)
     expect{ described_class.whereis('ruby') }.not_to raise_error
-    expect(described_class.whereis('ruby')).to be_kind_of(Array).or be_nil
+    expect(described_class.whereis('ruby')).to be_a(Array).or be_nil
   end
 
   example 'whereis accepts an optional second argument' do
@@ -43,7 +43,7 @@
 
   example 'whereis returns expected values' do
     expect{ @actual_locs = described_class.whereis(ruby) }.not_to raise_error
-    expect(@actual_locs).to be_kind_of(Array)
+    expect(@actual_locs).to be_a(Array)
     expect((@expected_locs & @actual_locs).size > 0).to be true
   end
 

spec/which_spec.rb

@@ -40,7 +40,7 @@
   example 'which method basic functionality' do
     expect(described_class).to respond_to(:which)
     expect{ described_class.which(@ruby) }.not_to raise_error
-    expect(described_class.which(@ruby)).to be_kind_of(String)
+    expect(described_class.which(@ruby)).to be_a(String)
   end
 
   example 'which accepts an optional path to search' do
@@ -92,7 +92,7 @@
   end
 
   example 'resolves with with ~', :unix_only => true do
-    old_home = ENV['HOME']
+    old_home = Dir.home
     ENV['HOME'] = Dir::Tmpname.tmpdir
     program = Tempfile.new(['program', '.sh'])
     described_class.chmod(755, program.path)