diff --git a/Gemfile b/Gemfile
index 8a48bba1..3e553ad9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,14 +1,12 @@
 source 'https://rubygems.org'
 
 gem "activesupport", require: false
-gem "rubocop", require: false
+gem "rubocop", "~> 0.37.2", require: false
 gem "rubocop-rspec", require: false
 gem "safe_yaml"
 gem "pry", require: false
 
 group :test do
-  gem "mocha"
   gem "rake"
-  gem "minitest"
-  gem "minitest-reporters"
+  gem "rspec"
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 06948bbb..5a209965 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,65 +1,67 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (4.2.4)
+    activesupport (4.2.5.1)
       i18n (~> 0.7)
       json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    ansi (1.5.0)
     ast (2.2.0)
-    astrolabe (1.3.1)
-      parser (~> 2.2)
-    builder (3.2.2)
     coderay (1.1.0)
+    diff-lcs (1.2.5)
     i18n (0.7.0)
     json (1.8.3)
-    metaclass (0.0.4)
     method_source (0.8.2)
-    minitest (5.8.0)
-    minitest-reporters (1.0.20)
-      ansi
-      builder
-      minitest (>= 5.0)
-      ruby-progressbar
-    mocha (1.1.0)
-      metaclass (~> 0.0.1)
-    parser (2.2.3.0)
-      ast (>= 1.1, < 3.0)
+    minitest (5.8.4)
+    parser (2.3.0.4)
+      ast (~> 2.2)
     powerpack (0.1.1)
-    pry (0.10.1)
+    pry (0.10.3)
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
-    rainbow (2.0.0)
-    rake (10.4.2)
-    rubocop (0.35.1)
-      astrolabe (~> 1.3)
-      parser (>= 2.2.3.0, < 3.0)
+    rainbow (2.1.0)
+    rake (10.5.0)
+    rspec (3.3.0)
+      rspec-core (~> 3.3.0)
+      rspec-expectations (~> 3.3.0)
+      rspec-mocks (~> 3.3.0)
+    rspec-core (3.3.1)
+      rspec-support (~> 3.3.0)
+    rspec-expectations (3.3.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.3.0)
+    rspec-mocks (3.3.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.3.0)
+    rspec-support (3.3.0)
+    rubocop (0.37.2)
+      parser (>= 2.3.0.4, < 3.0)
       powerpack (~> 0.1)
       rainbow (>= 1.99.1, < 3.0)
       ruby-progressbar (~> 1.7)
-      tins (<= 1.6.0)
-    rubocop-rspec (1.3.0)
+      unicode-display_width (~> 0.3)
+    rubocop-rspec (1.3.1)
     ruby-progressbar (1.7.5)
     safe_yaml (1.0.4)
     slop (3.6.0)
     thread_safe (0.3.5)
-    tins (1.6.0)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
+    unicode-display_width (0.3.1)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   activesupport
-  minitest
-  minitest-reporters
-  mocha
   pry
   rake
-  rubocop
+  rspec
+  rubocop (~> 0.37.2)
   rubocop-rspec
   safe_yaml
+
+BUNDLED WITH
+   1.11.2
diff --git a/Rakefile b/Rakefile
index c3d10e07..7b48a012 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,10 +1,5 @@
-require 'rake/testtask'
+require "rspec/core/rake_task"
 
-Rake.add_rakelib 'lib/tasks'
-
-Rake::TestTask.new do |t|
-  t.test_files = Dir.glob('spec/**/*_spec.rb')
-  t.libs = %w[lib spec]
-end
-
-task(default: :test)
+Rake.add_rakelib "lib/tasks"
+RSpec::Core::RakeTask.new(:spec)
+task default: :spec
diff --git a/config/cops.yml b/config/cops.yml
index 450e5d70..9c647e08 100644
--- a/config/cops.yml
+++ b/config/cops.yml
@@ -1,25 +1,27 @@
 Metrics/AbcSize:
   base_points: 1_000_000
-  violation_points: 70_000
+  overage_points: 70_000
 Metrics/BlockNesting:
   base_points: 100_000
+  overage_points: 50_000
 Metrics/ClassLength:
   base_points: 5_000_000
-  violation_points: 35_000
-Metrics/CyclomaticComplexity: # This check is per method
+  overage_points: 35_000
+Metrics/CyclomaticComplexity:
   base_points: 1_000_000
-  violation_points: 70_000
+  overage_points: 70_000
 Metrics/LineLength:
   base_points: 50_000
+  overage_points: 0
 Metrics/MethodLength:
   base_points: 1_000_000
-  violation_points: 70_000
+  overage_points: 70_000
 Metrics/ModuleLength:
   base_points: 5_000_000
-  violation_points: 35_000
+  overage_points: 35_000
 Metrics/ParameterList:
   base_points: 500_000
-  violation_points: 100_000
+  overage_points: 100_000
 Metrics/PerceivedComplexity:
   base_points: 1_000_000
-  violation_points: 70_000
+  overage_points: 70_000
diff --git a/lib/cc/engine/file_list_resolver.rb b/lib/cc/engine/file_list_resolver.rb
index 4a9874df..2db1771a 100644
--- a/lib/cc/engine/file_list_resolver.rb
+++ b/lib/cc/engine/file_list_resolver.rb
@@ -1,11 +1,11 @@
 module CC
   module Engine
     class FileListResolver
-      def initialize(code:, engine_config: {}, rubocop_config_store:)
-        @code = code
+      def initialize(root:, engine_config: {}, config_store:)
+        @root = root
         @exclude_paths = engine_config["exclude_paths"] || []
         @include_paths = engine_config["include_paths"]
-        @rubocop_config_store = rubocop_config_store
+        @config_store = config_store
       end
 
       def expanded_list
@@ -39,7 +39,7 @@ def include_based_files_to_inspect
       end
 
       def local_path(path)
-        realpath = Pathname.new(@code).realpath.to_s
+        realpath = Pathname.new(@root).realpath.to_s
         path.gsub(%r{^#{realpath}/}, '')
       end
 
@@ -47,13 +47,13 @@ def rubocop_file_to_include?(file)
         if file =~ /\.rb$/
           true
         else
-          dir, basename = File.split(file)
-          @rubocop_config_store.for(dir).file_to_include?(basename)
+          root, basename = File.split(file)
+          @config_store.for(root).file_to_include?(basename)
         end
       end
 
       def rubocop_runner
-        @rubocop_runner ||= RuboCop::Runner.new({}, @rubocop_config_store)
+        @rubocop_runner ||= RuboCop::Runner.new({}, @config_store)
       end
     end
   end
diff --git a/lib/cc/engine/issue.rb b/lib/cc/engine/issue.rb
new file mode 100644
index 00000000..2eccd032
--- /dev/null
+++ b/lib/cc/engine/issue.rb
@@ -0,0 +1,122 @@
+require 'safe_yaml'
+SafeYAML::OPTIONS[:default_mode] = :safe
+
+module CC
+  module Engine
+    class Issue < SimpleDelegator
+      MULTIPLIER_REGEX = %r{\[([\d\.]+)\/([\d\.]+)\]}
+      DEFAULT_REMEDIATION_POINTS = 50_000
+      DEFAULT_BASE_POINTS = 200_000
+      DEFAULT_OVERAGE_POINTS = 50_000
+
+      def initialize(issue, path, cop_list: nil)
+        @path = path
+        @cop_list = cop_list
+
+        super(issue)
+      end
+
+      # rubocop:disable Metrics/MethodLength
+      def to_json
+        hash = {
+          type: "Issue",
+          check_name: "Rubocop/#{cop_name}",
+          description: message,
+          categories: [category],
+          remediation_points: remediation_points,
+          location: {
+            path: path,
+            positions: positions,
+          },
+        }
+        hash[:content] = { body: content_body } if content_body.present?
+        hash.to_json
+      end
+
+      def remediation_points
+        if multiplier?
+          base_points + overage_points
+        else
+          cop_definition.fetch("remediation_points", DEFAULT_REMEDIATION_POINTS)
+        end
+      end
+
+      private
+
+      attr_reader :path
+
+      def multiplier?
+        message.match(MULTIPLIER_REGEX)
+      end
+
+      def base_points
+        cop_definition.fetch("base_points", DEFAULT_BASE_POINTS)
+      end
+
+      def cop_definition
+        @cop_definition ||= cop_list.fetch(cop_name, {})
+      end
+
+      def cop_list
+        @cop_list ||= YAML.load_file(expand_config_path("cops.yml"))
+      end
+
+      def expand_config_path(path)
+        File.expand_path("../../../../config/#{path}", __FILE__)
+      end
+
+      def overage_points
+        overage_points = cop_definition.
+          fetch("overage_points", DEFAULT_OVERAGE_POINTS)
+
+        overage_points * multiplier
+      end
+
+      def multiplier
+        result = message.scan(MULTIPLIER_REGEX)
+        score, threshold = result[0]
+        score.to_i - threshold.to_i
+      end
+
+      def category
+        CategoryParser.new(cop_name).category
+      end
+
+      def positions
+        {
+          begin: {
+            column: columns.first,
+            line: lines.first,
+          },
+          end: {
+            column: columns.last,
+            line: lines.last,
+          }
+        }
+      end
+
+      # Increments column values as columns are 0-based in parser
+      def columns
+        return @columns if defined?(@columns)
+
+        end_column = location.try(:last_column) || location.column
+        @columns = [location.column + 1, end_column + 1]
+      end
+
+      def lines
+        return @lines if defined?(@lines)
+
+        begin_line = location.try(:first_line) || location.line
+        end_line = location.try(:last_line) || location.line
+        @lines = [begin_line, end_line]
+      end
+
+      def content_body
+        return @content_body if defined?(@content_body)
+
+        content_path = expand_config_path("contents/#{cop_name.underscore}.md")
+        @content_body = File.exist?(content_path) && File.read(content_path)
+      end
+    end
+  end
+end
diff --git a/lib/cc/engine/rubocop.rb b/lib/cc/engine/rubocop.rb
index a88cc9ad..35eacefd 100644
--- a/lib/cc/engine/rubocop.rb
+++ b/lib/cc/engine/rubocop.rb
@@ -1,127 +1,59 @@
 require "json"
+require "delegate"
 require "pathname"
 require "rubocop"
+require "rubocop/config_patch"
 require "rubocop/cop/method_complexity_patch"
 require "rubocop/cop/method_length"
 require "rubocop/cop/class_length"
+require "cc/engine/source_file"
 require "cc/engine/category_parser"
 require "cc/engine/file_list_resolver"
-require "cc/engine/violation_decorator"
+require "cc/engine/issue"
 require "active_support"
 require "active_support/core_ext"
 
 module CC
   module Engine
     class Rubocop
-      def initialize(code, engine_config, io)
-        @code = code
+      def initialize(root, engine_config, io)
+        @root = root
         @engine_config = engine_config || {}
         @io = io
       end
 
       def run
-        Dir.chdir(@code) do
+        Dir.chdir(root) do
           files_to_inspect.each do |path|
-            inspect_file(path)
+            SourceFile.new(
+              config_store: config_store.for(path),
+              io: io,
+              path: path,
+              root: root,
+            ).inspect
           end
         end
       end
 
       private
 
-      def files_to_inspect
-        @file_list_resolver = FileListResolver.new(
-          code: @code,
-          engine_config: @engine_config,
-          rubocop_config_store: rubocop_config_store
-        )
-        @file_list_resolver.expanded_list
-      end
+      attr_reader :root, :engine_config, :io
 
-      def category(cop_name)
-        CategoryParser.new(cop_name).category
-      end
-
-      def inspect_file(path)
-        parsed = RuboCop::ProcessedSource.from_file(path)
-        rubocop_team_for_path(path).inspect_file(parsed).each do |violation|
-          next if violation.disabled?
-          decorated_violation = ViolationDecorator.new(violation)
-          json = violation_json(decorated_violation, local_path(path))
-          @io.print "#{json}\0"
-        end
-      end
-
-      def local_path(path)
-        realpath = Pathname.new(@code).realpath.to_s
-        path.gsub(%r{^#{realpath}/}, '')
+      def files_to_inspect
+        @files_to_inspect ||= FileListResolver.new(
+          config_store: config_store,
+          engine_config: engine_config,
+          root: root,
+        ).expanded_list
       end
 
-      def rubocop_config_store
-        @rubocop_config_store ||= begin
-          Dir.chdir(@code) do
-            config_store = RuboCop::ConfigStore.new
-            if (config_file = @engine_config["config"])
-              config_store.options_config = config_file
-            end
-            config_store
+      def config_store
+        @config_store ||= RuboCop::ConfigStore.new.tap do |config_store|
+          if (config_file = engine_config["config"])
+            config_store.options_config = config_file
           end
         end
       end
-
-      def rubocop_team_for_path(path)
-        rubocop_config = rubocop_config_store.for(path)
-        RuboCop::Cop::Team.new(RuboCop::Cop::Cop.all, rubocop_config)
-      end
-
-      def violation_positions(location)
-        if location.is_a?(RuboCop::Cop::Lint::Syntax::PseudoSourceRange)
-          first_line = location.line
-          last_line = location.line
-          first_column = location.column
-          last_column = location.column
-        else
-          first_line = location.first_line
-          last_line = location.last_line
-          first_column = location.column
-          last_column = location.last_column
-        end
-
-        {
-          begin: {
-            column: first_column + 1, # columns are 0-based in Parser
-            line: first_line,
-          },
-          end: {
-            column: last_column + 1,
-            line: last_line,
-          }
-        }
-      end
-
-      def violation_json(violation, local_path)
-        violation_hash = {
-          type: "Issue",
-          check_name: "Rubocop/#{violation.cop_name}",
-          description: violation.message,
-          categories: [category(violation.cop_name)],
-          remediation_points: violation.remediation_points,
-          location: {
-            path: local_path,
-            positions: violation_positions(violation.location),
-          },
-        }
-        body = content_body(violation.cop_name)
-        violation_hash.merge!(content: { body: body }) if body.present?
-        violation_hash.to_json
-      end
-
-      def content_body(cop_name)
-        path = File.expand_path(
-          "../../../../config/contents/#{cop_name.underscore}.md", __FILE__
-        )
-        File.exist?(path) ? File.read(path) : nil
-      end
     end
   end
 end
diff --git a/lib/cc/engine/source_file.rb b/lib/cc/engine/source_file.rb
new file mode 100644
index 00000000..1c1ef93c
--- /dev/null
+++ b/lib/cc/engine/source_file.rb
@@ -0,0 +1,42 @@
+module CC
+  module Engine
+    class SourceFile
+      def initialize(config_store:, io:, path:, root:)
+        @config_store = config_store
+        @io = io
+        @path = path
+        @root = root
+      end
+
+      def inspect
+        rubocop_team.inspect_file(processed_source).each do |offense|
+          next if offense.disabled?
+
+          io.print Issue.new(offense, display_path).to_json
+          io.print "\0"
+        end
+      end
+
+      private
+
+      attr_reader :config_store, :io, :path, :root
+
+      def processed_source
+        RuboCop::ProcessedSource.from_file(path, target_ruby_version)
+      end
+
+      def target_ruby_version
+        config_store["AllCops"] && config_store["AllCops"]["TargetRubyVersion"]
+      end
+
+      def rubocop_team
+        RuboCop::Cop::Team.new(RuboCop::Cop::Cop.all, config_store)
+      end
+
+      def display_path
+        realpath = Pathname.new(root).realpath.to_s
+        path.gsub(%r{^#{realpath}/}, "")
+      end
+    end
+  end
+end
diff --git a/lib/cc/engine/violation_decorator.rb b/lib/cc/engine/violation_decorator.rb
deleted file mode 100644
index ea73e343..00000000
--- a/lib/cc/engine/violation_decorator.rb
+++ /dev/null
@@ -1,57 +0,0 @@
-require 'safe_yaml'
-SafeYAML::OPTIONS[:default_mode] = :safe
-
-module CC
-  module Engine
-    class ViolationDecorator < SimpleDelegator
-      MULTIPLIER_REGEX = %r{\[([\d\.]+)\/([\d\.]+)\]}
-
-      DEFAULT_REMEDIATION_POINTS = 200_000
-      DEFAULT_POINTS_PER_VIOLATION = 50_000
-
-      def remediation_points
-        if multiplier?
-          base_points + violation_points
-        else
-          base_points
-        end
-      end
-
-      private
-
-      def base_points
-        cop_list.
-          fetch(cop_name, {}).
-          fetch("base_points", DEFAULT_REMEDIATION_POINTS)
-      end
-
-      def violation_points
-        per_violation_points = cop_list.
-          fetch(cop_name, {}).
-          fetch("violation_points", DEFAULT_POINTS_PER_VIOLATION)
-
-        per_violation_points * multiplier
-      end
-
-      def multiplier
-        result = message.scan(MULTIPLIER_REGEX)
-        score, max = result[0]
-        score.to_i - max.to_i
-      end
-
-      def multiplier?
-        message.match(MULTIPLIER_REGEX)
-      end
-
-      def cop_list
-        return @cop_list if @cop_list
-
-        cops_path = File.expand_path(
-          File.join(File.dirname(__FILE__), "../../../config/cops.yml")
-        )
-
-        @cop_list = YAML.load_file(cops_path)
-      end
-    end
-  end
-end
diff --git a/lib/rubocop/config_patch.rb b/lib/rubocop/config_patch.rb
new file mode 100644
index 00000000..92871057
--- /dev/null
+++ b/lib/rubocop/config_patch.rb
@@ -0,0 +1,10 @@
+RuboCop::Config.class_eval do
+  def reject_obsolete_cops
+    RuboCop::Config::OBSOLETE_COPS.each do |cop_name, message|
+      next unless key?(cop_name) || key?(cop_name.split('/').last)
+      message += "\n(obsolete configuration found in #{loaded_path}, please" \
+        ' update it)'
+      $stderr.puts message
+    end
+  end
+end
diff --git a/spec/cc/engine/category_parser_spec.rb b/spec/cc/engine/category_parser_spec.rb
index ac075e0e..ef63a929 100644
--- a/spec/cc/engine/category_parser_spec.rb
+++ b/spec/cc/engine/category_parser_spec.rb
@@ -3,16 +3,22 @@
 
 module CC::Engine
   describe CategoryParser do
-    it "returns a category for the cop name" do
-      CategoryParser.new("Rails/Delegate").category.must_equal("Clarity")
+    it "returns the category mapped to the full cop name if present" do
+      category_parser = CategoryParser.new("Rails/Delegate")
+
+      expect(category_parser.category).to eq("Clarity")
     end
 
-    it "returns a category for the cop" do
-      CategoryParser.new("Performance/Sup").category.must_equal("BugRisk")
+    it "returns the category mapped to the cop category if present" do
+      category_parser = CategoryParser.new("Rails/ScopeArgs")
+
+      expect(category_parser.category).to eq("BugRisk")
     end
 
-    it "returns a default" do
-      CategoryParser.new("Sup").category.must_equal("Style")
+    it "returns Style as the default" do
+      category_parser = CategoryParser.new("Pretend")
+
+      expect(category_parser.category).to eq("Style")
     end
   end
 end
diff --git a/spec/cc/engine/issue_spec.rb b/spec/cc/engine/issue_spec.rb
new file mode 100644
index 00000000..84c0cb6d
--- /dev/null
+++ b/spec/cc/engine/issue_spec.rb
@@ -0,0 +1,106 @@
+require "spec_helper"
+require "cc/engine/issue"
+
+module CC::Engine
+  describe Issue do
+    describe "#to_json" do
+      let(:issue) do
+        location = OpenStruct.new
+        location.first_line = 10
+        location.last_line = 10
+        location.column = 3
+        location.last_column = 99
+
+        offense = OpenStruct.new
+        offense.cop_name = "Metrics/LineLength"
+        offense.message = "Line too long [100/80]"
+        offense.location = location
+
+        Issue.new(offense, "app/models/user.rb")
+      end
+
+      it "returns a json issue for a Rubocop offense" do
+        attributes = JSON.parse(issue.to_json)
+
+        expect(attributes["type"]).to eq("Issue")
+        expect(attributes["check_name"]).to eq("Rubocop/Metrics/LineLength")
+        expect(attributes["description"]).to eq("Line too long [100/80]")
+        expect(attributes["categories"]).to eq(["Style"])
+        expect(attributes["remediation_points"]).to eq(50_000)
+        expect(attributes["location"]["path"]).to eq("app/models/user.rb")
+        expect(attributes["location"]["positions"]["begin"]["line"]).to eq(10)
+        expect(attributes["location"]["positions"]["end"]["line"]).to eq(10)
+        expect(attributes["location"]["positions"]["begin"]["column"]).to eq(4)
+        expect(attributes["location"]["positions"]["end"]["column"]).to eq(100)
+        expect(attributes["content"]["body"]).to include(
+          "This cop checks the length of lines in the source code."
+        )
+      end
+    end
+
+    describe "#remediation points" do
+      describe "cop has configured remediation points" do
+        describe "without a multiplier" do
+          it "returns the configured remediation points" do
+            cop_list = {
+              "Metrics/BlockNesting" => {
+                "remediation_points" => 300_000,
+              }
+            }
+            offense = OpenStruct.new
+            offense.cop_name = "Metrics/BlockNesting"
+            offense.message = "This has no multiplier"
+            issue = Issue.new(offense, "/code/file", cop_list: cop_list)
+
+            expect(issue.remediation_points).to eq(300_000)
+          end
+        end
+
+        describe "with a multiplier" do
+          it "calculates remediation points using the configured base and overage points" do
+            cop_list = {
+              "Metrics/AbcSize" => {
+                "base_points" => 5_000_000,
+                "overage_points" => 100_000,
+              }
+            }
+            offense = OpenStruct.new
+            offense.cop_name = "Metrics/AbcSize"
+            offense.message = "This has a [32/20] multiplier"
+            issue = Issue.new(offense, "/code/file", cop_list: cop_list)
+            base_points = 5_000_000
+            overage_points = 100_000 * 12
+
+            expect(issue.remediation_points).to eq(base_points + overage_points)
+          end
+        end
+      end
+
+      describe "cop has no configured remediation points" do
+        describe "without a multiplier" do
+          it "returns the default remediation points" do
+            offense = OpenStruct.new
+            offense.cop_name = "Some/UnconfiguredCop"
+            offense.message = "This has no multiplier"
+            issue = Issue.new(offense, "/code/file.rb")
+
+            expect(issue.remediation_points).to eq(Issue::DEFAULT_REMEDIATION_POINTS)
+          end
+        end
+
+        describe "with a multiplier" do
+          it "calculates remediation points using the default base and overage points" do
+            offense = OpenStruct.new
+            offense.cop_name = "Some/UnconfiguredCop"
+            offense.message = "This has a [22/20] multiplier"
+            issue = Issue.new(offense, "/code/file")
+            base_points = Issue::DEFAULT_BASE_POINTS
+            overage_points = Issue::DEFAULT_OVERAGE_POINTS * 2
+
+            expect(issue.remediation_points).to eq(base_points + overage_points)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/cc/engine/rubocop_spec.rb b/spec/cc/engine/rubocop_spec.rb
index 86932002..7965f895 100644
--- a/spec/cc/engine/rubocop_spec.rb
+++ b/spec/cc/engine/rubocop_spec.rb
@@ -18,7 +18,7 @@ def method
 
         output = run_engine
 
-        assert includes_check?(output, "Lint/UselessAssignment")
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be true
       end
 
       it "reads the configured ruby_style file" do
@@ -38,8 +38,8 @@ def method
         config = { "config" => "rubocop.yml" }
         output = run_engine(config)
 
-        assert includes_check?(output, "Style/AndOr")
-        assert !includes_check?(output, "Lint/UselessAssignment")
+        expect(includes_check?(output, "Style/AndOr")).to be true
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be false
       end
 
       it "respects the default .rubocop.yml file" do
@@ -58,8 +58,8 @@ def method
 
         output = run_engine
 
-        assert includes_check?(output, "Style/AndOr")
-        assert !includes_check?(output, "Lint/UselessAssignment")
+        expect(includes_check?(output, "Style/AndOr")).to be true
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be false
       end
 
       it "reads a file with a #!.*ruby declaration at the top" do
@@ -73,7 +73,8 @@ def method
           end
         EORUBY
         output = run_engine
-        assert includes_check?(output, "Lint/UselessAssignment")
+
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be true
       end
 
       it "uses excludes from the specified YAML config" do
@@ -92,7 +93,8 @@ def method
         )
         config = { "config" => "rubocop.yml" }
         output = run_engine(config)
-        assert !includes_check?(output, "Lint/UselessAssignment")
+
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be false
       end
 
       it "uses exclusions passed in via the config hash" do
@@ -107,7 +109,8 @@ def method
         EORUBY
         config = { "exclude_paths" => ["my_script"] }
         output = run_engine(config)
-        assert !includes_check?(output, "Lint/UselessAssignment")
+
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be false
       end
 
       it "layers config exclusions on top of the YAML config" do
@@ -129,11 +132,12 @@ def method
         )
         config = { "config" => "rubocop.yml", "exclude_paths" => ["bar.rb"] }
         output = run_engine(config)
-        assert !includes_check?(output, "Lint/UselessAssignment")
+
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be false
       end
 
       it "handles different locations properly" do
-        RuboCop::Cop::Team.any_instance.expects(:inspect_file).returns(
+        allow_any_instance_of(RuboCop::Cop::Team).to receive(:inspect_file).and_return(
           [
             OpenStruct.new(
               location: RuboCop::Cop::Lint::Syntax::PseudoSourceRange.new(
@@ -164,7 +168,8 @@ def method
             "end" => { "column" => 1, "line" => 1 }
           }
         }
-        assert_equal location, result["location"]
+
+        expect(result["location"]).to eq(location)
       end
 
       it "includes complete method body for cyclomatic complexity issue" do
@@ -192,7 +197,7 @@ def method(a,b,c,d,e,f,g)
           end
         EORUBY
         output = run_engine
-        assert includes_check?(output, "Metrics/CyclomaticComplexity")
+        expect(includes_check?(output, "Metrics/CyclomaticComplexity")).to be true
 
         json = JSON.parse('[' + output.split("\u0000").join(',') + ']')
 
@@ -206,7 +211,8 @@ def method(a,b,c,d,e,f,g)
             "end" => { "column" => 14, "line" => 21 }
           }
         }
-        assert_equal location, result["location"]
+
+        expect(result["location"]).to eq(location)
       end
 
       it "includes issue content when available" do
@@ -215,7 +221,7 @@ def method(a,b,c,d,e,f,g)
 
         output = run_engine
 
-        assert includes_content_for?(output, "Metrics/ClassLength")
+        expect(includes_content_for?(output, "Metrics/ClassLength")).to be true
       end
 
       it "uses only include_paths when they're passed in via the config hash" do
@@ -243,8 +249,9 @@ def method
         output = run_engine(
           "include_paths" => %w[included_root_file.rb subdir/]
         )
-        assert !includes_check?(output, "Lint/UselessAssignment")
-        assert !includes_check?(output, "Style/AndOr")
+
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be false
+        expect(includes_check?(output, "Style/AndOr")).to be false
       end
 
       it "ignores non-Ruby files even when passed in as include_paths" do
@@ -253,9 +260,11 @@ def method
         output = run_engine(
           "include_paths" => %w[config.yml]
         )
-        refute(issues(output).detect do |i|
+        issue = issues(output).detect do |i|
           i["description"] == "unexpected token tCOLON"
-        end)
+        end
+
+        expect(issue).to be nil
       end
 
       it "includes Ruby files even if they don't end with .rb" do
@@ -267,7 +276,8 @@ def method
           end
         EORUBY
         output = run_engine("include_paths" => %w[Rakefile])
-        assert includes_check?(output, "Lint/UselessAssignment")
+
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be true
       end
 
       it "skips local disables" do
@@ -280,7 +290,8 @@ def method
           end
         EORUBY
         output = run_engine
-        refute includes_check?(output, "Lint/UselessAssignment")
+
+        expect(includes_check?(output, "Lint/UselessAssignment")).to be false
       end
 
       it "shows full source of long methods" do
@@ -292,12 +303,12 @@ def method
         EORUBY
         output = run_engine
         issues = output.split("\0").map { |issue| JSON.parse(issue) }
-        violation = issues.find do |issue|
-          issue["check_name"] == "Rubocop/Metrics/MethodLength"
+        issue = issues.find do |i|
+          i["check_name"] == "Rubocop/Metrics/MethodLength"
         end
 
-        assert_equal 1, violation["location"]["positions"]["begin"]["line"]
-        assert_equal 14, violation["location"]["positions"]["end"]["line"]
+        expect(issue["location"]["positions"]["begin"]["line"]).to eq(1)
+        expect(issue["location"]["positions"]["end"]["line"]).to eq(14)
       end
 
       it "shows full source of long classes" do
@@ -308,12 +319,12 @@ class Awesome
         EORUBY
         output = run_engine
         issues = output.split("\0").map { |issue| JSON.parse(issue) }
-        violation = issues.find do |issue|
-          issue["check_name"] == "Rubocop/Metrics/ClassLength"
+        issue = issues.find do |i|
+          i["check_name"] == "Rubocop/Metrics/ClassLength"
         end
 
-        assert_equal 1, violation["location"]["positions"]["begin"]["line"]
-        assert_equal 105, violation["location"]["positions"]["end"]["line"]
+        expect(issue["location"]["positions"]["begin"]["line"]).to eq(1)
+        expect(issue["location"]["positions"]["end"]["line"]).to eq(105)
       end
 
       def includes_check?(output, cop_name)
diff --git a/spec/cc/engine/violation_decorator_spec.rb b/spec/cc/engine/violation_decorator_spec.rb
deleted file mode 100644
index 8c1f9d88..00000000
--- a/spec/cc/engine/violation_decorator_spec.rb
+++ /dev/null
@@ -1,37 +0,0 @@
-require "spec_helper"
-require "cc/engine/violation_decorator"
-
-module CC::Engine
-  describe ViolationDecorator do
-    describe "#remediation points" do
-      it "returns remediation points for violation" do
-        fake_violation = Minitest::Mock.new
-        fake_violation.expect :cop_name, :unknown_cop
-        fake_violation.expect :message, "This has no multiplier!"
-
-        decorated_violation = ViolationDecorator.new(fake_violation)
-
-        decorated_violation.remediation_points.must_equal(
-          ViolationDecorator::DEFAULT_REMEDIATION_POINTS
-        )
-      end
-
-      it "returns remedation points plus per violation points multiplied by overage" do
-        fake_violation = Minitest::Mock.new
-        fake_violation.expect :cop_name, :unknown_cop
-        fake_violation.expect :cop_name, :unknown_cop
-        fake_violation.expect :message, "This has [22/20] multiplier!"
-        fake_violation.expect :message, "This has [22/20] multiplier!"
-
-        decorated_violation = ViolationDecorator.new(fake_violation)
-
-        violation_pointss = ViolationDecorator::DEFAULT_POINTS_PER_VIOLATION * 2
-        base_points = ViolationDecorator::DEFAULT_REMEDIATION_POINTS
-
-        decorated_violation.remediation_points.must_equal(
-          violation_pointss + base_points
-        )
-      end
-    end
-  end
-end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 91472195..a5796422 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,5 +1 @@
-require 'minitest/spec'
-require 'minitest/autorun'
-require "minitest/reporters"
-require "mocha/mini_test"
-Minitest::Reporters.use! Minitest::Reporters::DefaultReporter.new
+require "rspec"