diff --git a/.travis.yml b/.travis.yml
index dd36cee..0a59ef7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,6 @@
 language: ruby
 rvm:
-  - 1.9.2
-  - 1.9.3
-  - 2.0.0
-  - jruby-19mode
-  - rbx-19mode
+  - 2.4
+  - 2.5
+  - 2.6
+  - 2.7
diff --git a/Rakefile b/Rakefile
index abd0206..7a58f1b 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,11 +1,13 @@
-require "bundler/gem_tasks"
+# frozen_string_literal: true
+
+require 'bundler/gem_tasks'
 
 require 'rake/testtask'
 
 Rake::TestTask.new do |t|
-  t.libs << "test"
+  t.libs << 'test'
   t.test_files = FileList['test/*_test.rb']
   t.verbose = true
 end
 
-task :default => :test
+task default: :test
diff --git a/json-merge_patch.gemspec b/json-merge_patch.gemspec
index 4138816..62cf7f2 100644
--- a/json-merge_patch.gemspec
+++ b/json-merge_patch.gemspec
@@ -1,24 +1,26 @@
-# coding: utf-8
-lib = File.expand_path('../lib', __FILE__)
+# frozen_string_literal: true
+
+lib = File.expand_path('lib', __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'json/merge_patch/version'
 
 Gem::Specification.new do |spec|
-  spec.name          = "json-merge_patch"
+  spec.name          = 'json-merge_patch'
   spec.version       = JSON::MergePatch::VERSION
-  spec.authors       = ["Steve Klabnik"]
-  spec.email         = ["steve@steveklabnik.com"]
-  spec.description   = %q{An implementation of the json-merge-patch draft.}
-  spec.summary       = %q{An implementation of the json-merge-patch draft.}
-  spec.homepage      = "http://json-merge-patch.herokuapp.com/"
-  spec.license       = "MIT"
+  spec.authors       = ['Steve Klabnik']
+  spec.email         = ['steve@steveklabnik.com']
+  spec.description   = 'An implementation of the json-merge-patch draft.'
+  spec.summary       = 'An implementation of the json-merge-patch draft.'
+  spec.homepage      = 'http://json-merge-patch.herokuapp.com/'
+  spec.license       = 'MIT'
 
-  spec.files         = `git ls-files`.split($/)
+  spec.files         = `git ls-files`.split($INPUT_RECORD_SEPARATOR)
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
-  spec.require_paths = ["lib"]
+  spec.require_paths = ['lib']
 
-  spec.add_development_dependency "bundler", "~> 1.3"
-  spec.add_development_dependency "rake"
-  spec.add_development_dependency "minitest"
+  spec.required_ruby_version = '>= 2.4'
+  spec.add_development_dependency 'bundler'
+  spec.add_development_dependency 'minitest'
+  spec.add_development_dependency 'rake'
 end
diff --git a/lib/json/merge_patch.rb b/lib/json/merge_patch.rb
index 3f4e3d7..2eb21d1 100644
--- a/lib/json/merge_patch.rb
+++ b/lib/json/merge_patch.rb
@@ -58,7 +58,7 @@ def is_array_or_primitive?(obj)
     end
 
     def is_primitive?(val)
-      [ String, Fixnum,
+      [ String, Integer, Float,
         TrueClass, FalseClass,
         NilClass
       ].include?(val.class)
diff --git a/lib/json/merge_patch/version.rb b/lib/json/merge_patch/version.rb
index d1656a9..40f9a8a 100644
--- a/lib/json/merge_patch/version.rb
+++ b/lib/json/merge_patch/version.rb
@@ -3,6 +3,6 @@
 module JSON
   class MergePatch
     # The current version of json-merge_patch
-    VERSION = "1.1.0"
+    VERSION = "2.0.0"
   end
 end
diff --git a/test/merge_patch_test.rb b/test/merge_patch_test.rb
index 60a3da3..758f288 100644
--- a/test/merge_patch_test.rb
+++ b/test/merge_patch_test.rb
@@ -1,214 +1,200 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 require 'json/merge_patch'
 
-describe "Section 1" do
-=begin
-1.  If either the root of the JSON data provided in the payload or
-    the root of the target resource are JSON Arrays, the target
-    resource is to be replaced, in whole, by the provided data.  Any
-    object member contained in the provided data whose value is
-    explicitly null is to be treated as if the member was undefined.
-=end
+describe 'Section 1' do
+  # 1.  If either the root of the JSON data provided in the payload or
+  #     the root of the target resource are JSON Arrays, the target
+  #     resource is to be replaced, in whole, by the provided data.  Any
+  #     object member contained in the provided data whose value is
+  #     explicitly null is to be treated as if the member was undefined.
 
-  describe "if the root of the data provided is an array" do
-    let(:merge_patch) { %q'["foo"]' }
+  describe 'if the root of the data provided is an array' do
+    let(:merge_patch) { '["foo"]' }
 
-    it "replaces the root whole" do
-      document = %q'{"foo":"bar"}'
+    it 'replaces the root whole' do
+      document = '{"foo":"bar"}'
 
-      expected = %q'["foo"]'
+      expected = '["foo"]'
 
       assert_equal expected, JSON.merge(document, merge_patch)
     end
   end
 
-  describe "if the root of the target resource is an array" do
-    let(:document) { %q'["foo"]' }
+  describe 'if the root of the target resource is an array' do
+    let(:document) { '["foo"]' }
 
-    it "replaces the root whole" do
-      merge_patch = %q'{"foo":"bar","bar":null}'
+    it 'replaces the root whole' do
+      merge_patch = '{"foo":"bar","bar":null}'
 
-      expected = %q'{"foo":"bar"}'
+      expected = '{"foo":"bar"}'
 
       assert_equal expected, JSON.merge(document, merge_patch)
     end
   end
 end
 
-describe "section 2" do
-=begin
-2.  If the root of the JSON data provided in the payload is an
-       Object, for each distinct member specified within that object:
-=end
+describe 'section 2' do
+  # 2.  If the root of the JSON data provided in the payload is an
+  #        Object, for each distinct member specified within that object:
 
-  describe "part 1" do
-=begin
-*  If the member is currently undefined within the target
-   resource, and the given value is not null, the member and the
-   value are to be added to the target.  Any object member
-   contained in the provided data whose value is explicitly null
-   is to be treated as if the member were undefined.
-=end
-    it "adds members" do
-      document = %q'{"foo":"bar"}'
+  describe 'part 1' do
+    # *  If the member is currently undefined within the target
+    #    resource, and the given value is not null, the member and the
+    #    value are to be added to the target.  Any object member
+    #    contained in the provided data whose value is explicitly null
+    #    is to be treated as if the member were undefined.
+    it 'adds members' do
+      document = '{"foo":"bar"}'
 
-      merge_patch = %q'{"foo":"bar","baz":"quxx"}'
+      merge_patch = '{"foo":"bar","baz":"quxx"}'
 
-      expected = %q'{"foo":"bar","baz":"quxx"}'
+      expected = '{"foo":"bar","baz":"quxx"}'
 
       assert_equal expected, JSON.merge(document, merge_patch)
     end
   end
 
-  describe "part 2" do
-=begin
-*  If the value is explicitly set to null and that member is
-   currently defined within the target resource, the existing
-   member is removed.
-=end
-    it "removes members" do
-      document = %q'{"foo":"bar"}'
+  describe 'part 2' do
+    # *  If the value is explicitly set to null and that member is
+    #    currently defined within the target resource, the existing
+    #    member is removed.
+    it 'removes members' do
+      document = '{"foo":"bar"}'
 
-      merge_patch = %q'{"foo":null}'
+      merge_patch = '{"foo":null}'
 
-      expected = %q'{}'
+      expected = '{}'
 
       assert_equal expected, JSON.merge(document, merge_patch)
     end
   end
 
-  describe "part 3" do
-=begin
-*  If the value is either a non-null JSON primitive or an Array
-   and that member is currently defined within the target
-   resource, the existing value for that member is to be replaced
-   with that provided.  Any object member contained in the
-   provided data whose value is explicitly null is to be treated
-   as if the member were undefined.
-=end
-    describe "object" do
-      it "replaces members" do
-        document = %q'{"foo":"bar"}'
+  describe 'part 3' do
+    # *  If the value is either a non-null JSON primitive or an Array
+    #    and that member is currently defined within the target
+    #    resource, the existing value for that member is to be replaced
+    #    with that provided.  Any object member contained in the
+    #    provided data whose value is explicitly null is to be treated
+    #    as if the member were undefined.
+    describe 'object' do
+      it 'replaces members' do
+        document = '{"foo":"bar"}'
 
-        merge_patch = %q'{"foo":"baz"}'
+        merge_patch = '{"foo":"baz"}'
 
-        expected = %q'{"foo":"baz"}'
+        expected = '{"foo":"baz"}'
 
         assert_equal expected, JSON.merge(document, merge_patch)
       end
     end
   end
 
-  describe "part 4" do
-=begin
-*  If the value is a JSON object and that member is currently
-   defined for the target resource and the existing value is a
-   JSON primitive or Array, the existing value is to be replaced
-   in whole by the object provided.  Any object member contained
-   in the provided data whose value is explicitly null is to be
-   treated as if the member was undefined.
-=end
-    describe "patch has a primitive" do
-      it "replaces members" do
-        document = %q'{"foo":{"bar":"baz"}}'
+  describe 'part 4' do
+    # *  If the value is a JSON object and that member is currently
+    #    defined for the target resource and the existing value is a
+    #    JSON primitive or Array, the existing value is to be replaced
+    #    in whole by the object provided.  Any object member contained
+    #    in the provided data whose value is explicitly null is to be
+    #    treated as if the member was undefined.
+    describe 'patch has a primitive' do
+      it 'replaces members' do
+        document = '{"foo":{"bar":"baz"}}'
 
-        merge_patch = %q'{"foo":2}'
+        merge_patch = '{"foo":2}'
 
-        expected = %q'{"foo":2}'
+        expected = '{"foo":2}'
 
         assert_equal expected, JSON.merge(document, merge_patch)
       end
     end
 
-    describe "patch has an array" do
-      it "replaces members" do
-        document = %q'{"foo":{"bar":"baz"}}'
+    describe 'patch has an array' do
+      it 'replaces members' do
+        document = '{"foo":{"bar":"baz"}}'
 
-        merge_patch = %q'{"foo":["bar"]}'
+        merge_patch = '{"foo":["bar"]}'
 
-        expected = %q'{"foo":["bar"]}'
+        expected = '{"foo":["bar"]}'
 
         assert_equal expected, JSON.merge(document, merge_patch)
       end
     end
   end
 
-  describe "part 5" do
-=begin
-*  If the value is a JSON object and that member is currently
-   defined within the target resource and the existing value is
-   also a JSON object, then recursively apply Rule #2 to each
-   object.
-=end
-    describe "nested objects" do
-      it "recursively " do
-        document = %q'{"foo":{"bar":"baz"}}'
+  describe 'part 5' do
+    # *  If the value is a JSON object and that member is currently
+    #    defined within the target resource and the existing value is
+    #    also a JSON object, then recursively apply Rule #2 to each
+    #    object.
+    describe 'nested objects' do
+      it 'recursively ' do
+        document = '{"foo":{"bar":"baz"}}'
 
-        merge_patch = %q'{"foo":{"bar":{"baz":"qux","dev":null}}}'
+        merge_patch = '{"foo":{"bar":{"baz":"qux","dev":null}}}'
 
-        expected = %q'{"foo":{"bar":{"baz":"qux"}}}'
+        expected = '{"foo":{"bar":{"baz":"qux"}}}'
 
         assert_equal expected, JSON.merge(document, merge_patch)
       end
     end
 
-    it "recursive removal" do
-      document = %q'{"foo":{"bar":"baz"}}'
+    it 'recursive removal' do
+      document = '{"foo":{"bar":"baz"}}'
 
-      merge_patch = %q'{"foo":{"bar":null}}'
+      merge_patch = '{"foo":{"bar":null}}'
 
-      expected = %q'{"foo":{}}'
+      expected = '{"foo":{}}'
 
       assert_equal expected, JSON.merge(document, merge_patch)
     end
   end
 
-  describe "part 6" do
-=begin
-*  Any member currently defined within the target resource that
-   does not explicitly appear within the patch is to remain
-   untouched and unmodified.
-=end
-    it "leaves well enough alone!" do
-      document = %q'{"content": "This will be unchanged"}'
+  describe 'part 6' do
+    # *  Any member currently defined within the target resource that
+    #    does not explicitly appear within the patch is to remain
+    #    untouched and unmodified.
+    it 'leaves well enough alone!' do
+      document = '{"content": "This will be unchanged"}'
 
-      merge_patch = %q'{}'
+      merge_patch = '{}'
 
-      expected = %q'{"content":"This will be unchanged"}'
+      expected = '{"content":"This will be unchanged"}'
 
       assert_equal expected, JSON.merge(document, merge_patch)
     end
   end
 end
 
-describe "missing coverage" do
-  it "deals with a nil patch" do
-    document = %q'{"foo":"bar"}'
-    expected = %q'{"foo":"bar"}'
+describe 'missing coverage' do
+  it 'deals with a nil patch' do
+    document = '{"foo":"bar"}'
+    expected = '{"foo":"bar"}'
 
     assert_equal expected, JSON::MergePatch.new(document, nil).call
   end
 
-  it "handles primitive true" do
-    document = %q'{"foo":"bar"}'
-    patch = %q'{"foo":true}'
-    expected = %q'{"foo":true}'
+  it 'handles primitive true' do
+    document = '{"foo":"bar"}'
+    patch = '{"foo":true}'
+    expected = '{"foo":true}'
 
     assert_equal expected, JSON.merge(document, patch)
   end
 
-  it "handles primitive false" do
-    document = %q'{"foo":"bar"}'
-    patch = %q'{"foo":false}'
-    expected = %q'{"foo":false}'
+  it 'handles primitive false' do
+    document = '{"foo":"bar"}'
+    patch = '{"foo":false}'
+    expected = '{"foo":false}'
 
     assert_equal expected, JSON.merge(document, patch)
   end
 end
 
-describe "README example" do
-  it "works properly" do
+describe 'README example' do
+  it 'works properly' do
     document = <<-JSON.strip_heredoc.chomp
     {
       "title": "Goodbye!",
@@ -232,14 +218,14 @@
     }
     JSON
 
-    expected = %q'{"title":"Hello!","author":{"givenName":"John"},"tags":["example"],"content":"This will be unchanged","phoneNumber":"+01-123-456-7890"}'
+    expected = '{"title":"Hello!","author":{"givenName":"John"},"tags":["example"],"content":"This will be unchanged","phoneNumber":"+01-123-456-7890"}'
 
     assert_equal expected, JSON.merge(document, merge_patch)
   end
 end
 
-describe "errors" do
-  it "throws an error when stuff goes wrong" do
+describe 'errors' do
+  it 'throws an error when stuff goes wrong' do
     assert_raises(JSON::MergeError) do
       JSON.merge(nil, nil)
     end
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 062bef7..1c8c304 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'simplecov'
 SimpleCov.start do
   add_filter do |source_file|
@@ -11,12 +13,10 @@
 require 'minitest/autorun'
 
 def pending
-  begin
-    yield
-    fail "OMG pending test passed."
-  rescue MiniTest::Assertion
-    skip "Still pending"
-  end
+  yield
+  raise 'OMG pending test passed.'
+rescue MiniTest::Assertion
+  skip 'Still pending'
 end
 
 class String