From 4d7a98341556614818223060ca94413b17e3d1e6 Mon Sep 17 00:00:00 2001
From: Gautham Goli <goligautham@gmail.com>
Date: Thu, 1 Jun 2017 00:57:24 +0530
Subject: [PATCH 1/3] audit: Port audit_checksum method to rubocop and add
 tests

---
 Library/.rubocop.yml                          |   3 +
 Library/Homebrew/dev-cmd/audit.rb             |  23 ---
 Library/Homebrew/rubocops.rb                  |   1 +
 Library/Homebrew/rubocops/checksum_cop.rb     |  61 ++++++
 .../Homebrew/rubocops/extend/formula_cop.rb   |   9 +-
 .../test/rubocops/checksum_cop_spec.rb        | 179 ++++++++++++++++++
 6 files changed, 251 insertions(+), 25 deletions(-)
 create mode 100644 Library/Homebrew/rubocops/checksum_cop.rb
 create mode 100644 Library/Homebrew/test/rubocops/checksum_cop_spec.rb

diff --git a/Library/.rubocop.yml b/Library/.rubocop.yml
index 19d8714141..dafb1221b7 100644
--- a/Library/.rubocop.yml
+++ b/Library/.rubocop.yml
@@ -12,6 +12,9 @@ FormulaAudit/Text:
 FormulaAudit/Caveats:
   Enabled: true
 
+FormulaAudit/Checksum:
+  Enabled: true
+
 FormulaAuditStrict/BottleBlock:
   Enabled: true
 
diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 0d9a630fdc..a6c71f795d 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -1246,7 +1246,6 @@ class ResourceAuditor
 
   def audit
     audit_version
-    audit_checksum
     audit_download_strategy
     audit_urls
     self
@@ -1273,28 +1272,6 @@ class ResourceAuditor
     problem "version #{version} should not end with an underline and a number"
   end
 
-  def audit_checksum
-    return unless checksum
-
-    case checksum.hash_type
-    when :md5
-      problem "MD5 checksums are deprecated, please use SHA256"
-      return
-    when :sha1
-      problem "SHA1 checksums are deprecated, please use SHA256"
-      return
-    when :sha256 then len = 64
-    end
-
-    if checksum.empty?
-      problem "#{checksum.hash_type} is empty"
-    else
-      problem "#{checksum.hash_type} should be #{len} characters" unless checksum.hexdigest.length == len
-      problem "#{checksum.hash_type} contains invalid characters" unless checksum.hexdigest =~ /^[a-fA-F0-9]+$/
-      problem "#{checksum.hash_type} should be lowercase" unless checksum.hexdigest == checksum.hexdigest.downcase
-    end
-  end
-
   def audit_download_strategy
     if url =~ %r{^(cvs|bzr|hg|fossil)://} || url =~ %r{^(svn)\+http://}
       problem "Use of the #{$&} scheme is deprecated, pass `:using => :#{Regexp.last_match(1)}` instead"
diff --git a/Library/Homebrew/rubocops.rb b/Library/Homebrew/rubocops.rb
index c4a38cdb77..4710654fa2 100644
--- a/Library/Homebrew/rubocops.rb
+++ b/Library/Homebrew/rubocops.rb
@@ -5,3 +5,4 @@ require_relative "./rubocops/components_redundancy_cop"
 require_relative "./rubocops/homepage_cop"
 require_relative "./rubocops/text_cop"
 require_relative "./rubocops/caveats_cop"
+require_relative "./rubocops/checksum_cop"
diff --git a/Library/Homebrew/rubocops/checksum_cop.rb b/Library/Homebrew/rubocops/checksum_cop.rb
new file mode 100644
index 0000000000..17ce1e83e0
--- /dev/null
+++ b/Library/Homebrew/rubocops/checksum_cop.rb
@@ -0,0 +1,61 @@
+require_relative "./extend/formula_cop"
+
+module RuboCop
+  module Cop
+    module FormulaAudit
+      class Checksum < FormulaCop
+        def audit_formula(_node, _class_node, _parent_class_node, body_node)
+          %w[stable devel head].each do |name|
+            next unless spec_node = find_block(body_node, name.to_sym)
+            _, _, spec_body = *spec_node
+            audit_checksums(spec_body, name)
+            if name == "stable"
+              resource_blocks = find_blocks(body_node, :resource) +
+                                find_all_blocks(spec_body, :resource)
+            else
+              resource_blocks = find_all_blocks(spec_body, :resource)
+            end
+            resource_blocks.each do |rb|
+              _, _, resource_body = *rb
+              audit_checksums(resource_body, name, string_content(parameters(rb).first))
+            end
+          end
+        end
+
+        def audit_checksums(node, spec, resource_name = nil)
+          msg_prefix = if resource_name
+            "#{spec} resource \"#{resource_name}\": "
+          else
+            "#{spec}: "
+          end
+          if find_node_method_by_name(node, :md5)
+            problem "#{msg_prefix}MD5 checksums are deprecated, please use SHA256"
+          end
+
+          if find_node_method_by_name(node, :sha1)
+            problem "#{msg_prefix}SHA1 checksums are deprecated, please use SHA256"
+          end
+
+          checksum_node = find_node_method_by_name(node, :sha256)
+          return if checksum_node.nil?
+          checksum = parameters(checksum_node).first
+          if string_content(checksum).size.zero?
+            problem "#{msg_prefix}sha256 is empty"
+            return
+          end
+
+          if string_content(checksum).size != 64 && regex_match_group(checksum, /^\w*$/)
+            problem "#{msg_prefix}sha256 should be 64 characters"
+          end
+
+          unless regex_match_group(checksum, /^[a-f0-9]+$/i)
+            problem "#{msg_prefix}sha256 contains invalid characters"
+          end
+
+          return unless regex_match_group(checksum, /[A-F]+/)
+          problem "#{msg_prefix}sha256 should be lowercase"
+        end
+      end
+    end
+  end
+end
diff --git a/Library/Homebrew/rubocops/extend/formula_cop.rb b/Library/Homebrew/rubocops/extend/formula_cop.rb
index 75a3e72d5d..98280841cc 100644
--- a/Library/Homebrew/rubocops/extend/formula_cop.rb
+++ b/Library/Homebrew/rubocops/extend/formula_cop.rb
@@ -173,6 +173,12 @@ module RuboCop
         node.each_child_node(:block).select { |block_node| block_name == block_node.method_name }
       end
 
+      # Returns an array of block nodes of any depth below node in AST
+      def find_all_blocks(node, block_name)
+        return if node.nil?
+        node.each_descendant(:block).select { |block_node| block_name == block_node.method_name }
+      end
+
       # Returns a method definition node with method_name
       def find_method_def(node, method_name)
         return if node.nil?
@@ -250,8 +256,7 @@ module RuboCop
 
       # Returns the array of arguments of the method_node
       def parameters(method_node)
-        return unless method_node.send_type?
-        method_node.method_args
+        method_node.method_args if method_node.send_type? || method_node.block_type?
       end
 
       # Returns true if the given parameters are present in method call
diff --git a/Library/Homebrew/test/rubocops/checksum_cop_spec.rb b/Library/Homebrew/test/rubocops/checksum_cop_spec.rb
new file mode 100644
index 0000000000..c2caab73a5
--- /dev/null
+++ b/Library/Homebrew/test/rubocops/checksum_cop_spec.rb
@@ -0,0 +1,179 @@
+require "rubocop"
+require "rubocop/rspec/support"
+require_relative "../../extend/string"
+require_relative "../../rubocops/checksum_cop"
+
+describe RuboCop::Cop::FormulaAudit::Checksum do
+  subject(:cop) { described_class.new }
+
+  context "When auditing spec checksums" do
+    it "When the checksum is empty" do
+      source = <<-EOS.undent
+        class Foo < Formula
+          url 'http://example.com/foo-1.0.tgz'
+          stable do
+            url "https://github.com/foo-lang/foo-compiler/archive/0.18.0.tar.gz"
+            sha256 ""
+
+            resource "foo-package" do
+              url "https://github.com/foo-lang/foo-package/archive/0.18.0.tar.gz"
+              sha256 ""
+            end
+          end
+        end
+      EOS
+
+      expected_offenses = [{  message: "stable: sha256 is empty",
+                              severity: :convention,
+                              line: 5,
+                              column: 4,
+                              source: source },
+                           {  message: "stable resource \"foo-package\": sha256 is empty",
+                              severity: :convention,
+                              line: 9,
+                              column: 6,
+                              source: source }]
+
+      inspect_source(cop, source)
+
+      expected_offenses.zip(cop.offenses).each do |expected, actual|
+        expect_offense(expected, actual)
+      end
+    end
+
+    it "When the checksum is not 64 characters" do
+      source = <<-EOS.undent
+        class Foo < Formula
+          url 'http://example.com/foo-1.0.tgz'
+          stable do
+            url "https://github.com/foo-lang/foo-compiler/archive/0.18.0.tar.gz"
+            sha256 "5cf6e1ae0a645b426c0474cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea0e9ad"
+
+            resource "foo-package" do
+              url "https://github.com/foo-lang/foo-package/archive/0.18.0.tar.gz"
+              sha256 "5cf6e1ae0a645b426c047aaa4cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea0e9"
+            end
+          end
+        end
+      EOS
+
+      expected_offenses = [{  message: "stable: sha256 should be 64 characters",
+                              severity: :convention,
+                              line: 5,
+                              column: 12,
+                              source: source },
+                           {  message: "stable resource \"foo-package\": sha256 should be 64 characters",
+                              severity: :convention,
+                              line: 9,
+                              column: 14,
+                              source: source }]
+
+      inspect_source(cop, source)
+
+      expected_offenses.zip(cop.offenses).each do |expected, actual|
+        expect_offense(expected, actual)
+      end
+    end
+
+    it "When the checksum has invalid chars" do
+      source = <<-EOS.undent
+        class Foo < Formula
+          url 'http://example.com/foo-1.0.tgz'
+          stable do
+            url "https://github.com/foo-lang/foo-compiler/archive/0.18.0.tar.gz"
+            sha256 "5cf6e1ae0a645b426c0k7cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea0e9a"
+
+            resource "foo-package" do
+              url "https://github.com/foo-lang/foo-package/archive/0.18.0.tar.gz"
+              sha256 "5cf6e1ae0a645b426x047aa4cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea9"
+            end
+          end
+        end
+      EOS
+
+      expected_offenses = [{  message: "stable: sha256 contains invalid characters",
+                              severity: :convention,
+                              line: 5,
+                              column: 4,
+                              source: source },
+                           {  message: "stable resource \"foo-package\": sha256 contains invalid characters",
+                              severity: :convention,
+                              line: 9,
+                              column: 6,
+                              source: source }]
+
+      inspect_source(cop, source)
+
+      expected_offenses.zip(cop.offenses).each do |expected, actual|
+        expect_offense(expected, actual)
+      end
+    end
+
+    it "When the checksum has upper case characters" do
+      source = <<-EOS.undent
+        class Foo < Formula
+          url 'http://example.com/foo-1.0.tgz'
+          stable do
+            url "https://github.com/foo-lang/foo-compiler/archive/0.18.0.tar.gz"
+            sha256 "5cf6e1ae0A645b426c0a7cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea0e9a"
+
+            resource "foo-package" do
+              url "https://github.com/foo-lang/foo-package/archive/0.18.0.tar.gz"
+              sha256 "5cf6e1Ae0a645b426b047aa4cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea9"
+            end
+          end
+        end
+      EOS
+
+      expected_offenses = [{  message: "stable: sha256 should be lowercase",
+                              severity: :convention,
+                              line: 5,
+                              column: 21,
+                              source: source },
+                           {  message: "stable resource \"foo-package\": sha256 should be lowercase",
+                              severity: :convention,
+                              line: 9,
+                              column: 20,
+                              source: source }]
+
+      inspect_source(cop, source)
+
+      expected_offenses.zip(cop.offenses).each do |expected, actual|
+        expect_offense(expected, actual)
+      end
+    end
+
+    it "When auditing stable blocks outside spec blocks" do
+      source = <<-EOS.undent
+        class Foo < Formula
+          url 'http://example.com/foo-1.0.tgz'
+          resource "foo-outside" do
+            url "https://github.com/foo-lang/foo-outside/archive/0.18.0.tar.gz"
+            sha256 "A4cc7cd3f7d1605ffa1ac5755cf6e1ae0a645b426b047a6a39a8b2268ddc7ea9"
+          end
+          stable do
+            url "https://github.com/foo-lang/foo-compiler/archive/0.18.0.tar.gz"
+            sha256 "5cf6e1ae0a645b426c0a7cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea0e9a"
+
+            resource "foo-package" do
+              url "https://github.com/foo-lang/foo-package/archive/0.18.0.tar.gz"
+              sha256 "5cf6e1ae0a645b426b047aa4cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea9"
+            end
+          end
+        end
+      EOS
+
+      expected_offenses = [{  message: "stable resource \"foo-outside\": sha256 should be lowercase",
+                              severity: :convention,
+                              line: 5,
+                              column: 12,
+                              source: source }]
+
+      inspect_source(cop, source)
+
+      expected_offenses.zip(cop.offenses).each do |expected, actual|
+        expect_offense(expected, actual)
+      end
+    end
+  end
+end

From 77da75e7d6ecc2ca749eb939d8e24ad9e3dfc5e1 Mon Sep 17 00:00:00 2001
From: Gautham Goli <goligautham@gmail.com>
Date: Wed, 14 Jun 2017 15:37:37 +0530
Subject: [PATCH 2/3] Simplify Checksum cop by auditing all checksums

---
 Library/Homebrew/rubocops/checksum_cop.rb     | 63 +++++++++----------
 .../test/rubocops/checksum_cop_spec.rb        | 26 ++++----
 2 files changed, 41 insertions(+), 48 deletions(-)

diff --git a/Library/Homebrew/rubocops/checksum_cop.rb b/Library/Homebrew/rubocops/checksum_cop.rb
index 17ce1e83e0..d9e81a4eff 100644
--- a/Library/Homebrew/rubocops/checksum_cop.rb
+++ b/Library/Homebrew/rubocops/checksum_cop.rb
@@ -5,55 +5,48 @@ module RuboCop
     module FormulaAudit
       class Checksum < FormulaCop
         def audit_formula(_node, _class_node, _parent_class_node, body_node)
-          %w[stable devel head].each do |name|
-            next unless spec_node = find_block(body_node, name.to_sym)
-            _, _, spec_body = *spec_node
-            audit_checksums(spec_body, name)
-            if name == "stable"
-              resource_blocks = find_blocks(body_node, :resource) +
-                                find_all_blocks(spec_body, :resource)
-            else
-              resource_blocks = find_all_blocks(spec_body, :resource)
-            end
-            resource_blocks.each do |rb|
-              _, _, resource_body = *rb
-              audit_checksums(resource_body, name, string_content(parameters(rb).first))
-            end
+          return if body_node.nil?
+          if method_called_ever?(body_node, :md5)
+            problem "MD5 checksums are deprecated, please use SHA256"
+          end
+
+          if method_called_ever?(body_node, :sha1)
+            problem "SHA1 checksums are deprecated, please use SHA256"
+          end
+
+          sha256_calls = find_every_method_call_by_name(body_node, :sha256)
+          sha256_calls.each do |sha256_call|
+            sha256_node = get_checksum_node(sha256_call)
+            audit_sha256(sha256_node)
           end
         end
 
-        def audit_checksums(node, spec, resource_name = nil)
-          msg_prefix = if resource_name
-            "#{spec} resource \"#{resource_name}\": "
-          else
-            "#{spec}: "
-          end
-          if find_node_method_by_name(node, :md5)
-            problem "#{msg_prefix}MD5 checksums are deprecated, please use SHA256"
+        def get_checksum_node(call)
+          return if parameters(call).empty? || parameters(call).nil?
+          if parameters(call).first.str_type?
+            parameters(call).first
+          elsif parameters(call).first.hash_type?
+            parameters(call).first.keys.first
           end
+        end
 
-          if find_node_method_by_name(node, :sha1)
-            problem "#{msg_prefix}SHA1 checksums are deprecated, please use SHA256"
-          end
-
-          checksum_node = find_node_method_by_name(node, :sha256)
-          return if checksum_node.nil?
-          checksum = parameters(checksum_node).first
-          if string_content(checksum).size.zero?
-            problem "#{msg_prefix}sha256 is empty"
+        def audit_sha256(checksum)
+          return if checksum.nil?
+          if regex_match_group(checksum, /^$/)
+            problem "sha256 is empty"
             return
           end
 
           if string_content(checksum).size != 64 && regex_match_group(checksum, /^\w*$/)
-            problem "#{msg_prefix}sha256 should be 64 characters"
+            problem "sha256 should be 64 characters"
           end
 
-          unless regex_match_group(checksum, /^[a-f0-9]+$/i)
-            problem "#{msg_prefix}sha256 contains invalid characters"
+          if regex_match_group(checksum, /[^a-f0-9]+/i)
+            problem "sha256 contains invalid characters"
           end
 
           return unless regex_match_group(checksum, /[A-F]+/)
-          problem "#{msg_prefix}sha256 should be lowercase"
+          problem "sha256 should be lowercase"
         end
       end
     end
diff --git a/Library/Homebrew/test/rubocops/checksum_cop_spec.rb b/Library/Homebrew/test/rubocops/checksum_cop_spec.rb
index c2caab73a5..633f3117ac 100644
--- a/Library/Homebrew/test/rubocops/checksum_cop_spec.rb
+++ b/Library/Homebrew/test/rubocops/checksum_cop_spec.rb
@@ -23,15 +23,15 @@ describe RuboCop::Cop::FormulaAudit::Checksum do
         end
       EOS
 
-      expected_offenses = [{  message: "stable: sha256 is empty",
+      expected_offenses = [{  message: "sha256 is empty",
                               severity: :convention,
                               line: 5,
-                              column: 4,
+                              column: 12,
                               source: source },
-                           {  message: "stable resource \"foo-package\": sha256 is empty",
+                           {  message: "sha256 is empty",
                               severity: :convention,
                               line: 9,
-                              column: 6,
+                              column: 14,
                               source: source }]
 
       inspect_source(cop, source)
@@ -57,12 +57,12 @@ describe RuboCop::Cop::FormulaAudit::Checksum do
         end
       EOS
 
-      expected_offenses = [{  message: "stable: sha256 should be 64 characters",
+      expected_offenses = [{  message: "sha256 should be 64 characters",
                               severity: :convention,
                               line: 5,
                               column: 12,
                               source: source },
-                           {  message: "stable resource \"foo-package\": sha256 should be 64 characters",
+                           {  message: "sha256 should be 64 characters",
                               severity: :convention,
                               line: 9,
                               column: 14,
@@ -91,15 +91,15 @@ describe RuboCop::Cop::FormulaAudit::Checksum do
         end
       EOS
 
-      expected_offenses = [{  message: "stable: sha256 contains invalid characters",
+      expected_offenses = [{  message: "sha256 contains invalid characters",
                               severity: :convention,
                               line: 5,
-                              column: 4,
+                              column: 31,
                               source: source },
-                           {  message: "stable resource \"foo-package\": sha256 contains invalid characters",
+                           {  message: "sha256 contains invalid characters",
                               severity: :convention,
                               line: 9,
-                              column: 6,
+                              column: 31,
                               source: source }]
 
       inspect_source(cop, source)
@@ -125,12 +125,12 @@ describe RuboCop::Cop::FormulaAudit::Checksum do
         end
       EOS
 
-      expected_offenses = [{  message: "stable: sha256 should be lowercase",
+      expected_offenses = [{  message: "sha256 should be lowercase",
                               severity: :convention,
                               line: 5,
                               column: 21,
                               source: source },
-                           {  message: "stable resource \"foo-package\": sha256 should be lowercase",
+                           {  message: "sha256 should be lowercase",
                               severity: :convention,
                               line: 9,
                               column: 20,
@@ -163,7 +163,7 @@ describe RuboCop::Cop::FormulaAudit::Checksum do
         end
       EOS
 
-      expected_offenses = [{  message: "stable resource \"foo-outside\": sha256 should be lowercase",
+      expected_offenses = [{  message: "sha256 should be lowercase",
                               severity: :convention,
                               line: 5,
                               column: 12,

From 0e1c88e7aefb93a8e2cc927fa9a4e903ac015c57 Mon Sep 17 00:00:00 2001
From: Gautham Goli <goligautham@gmail.com>
Date: Fri, 16 Jun 2017 19:44:14 +0530
Subject: [PATCH 3/3] Refactor Checksum cop to add autocorrect method

---
 Library/.rubocop.yml                          |  3 ++
 Library/Homebrew/rubocops/checksum_cop.rb     | 38 ++++++++++------
 .../Homebrew/rubocops/extend/formula_cop.rb   | 11 +++++
 .../test/rubocops/checksum_cop_spec.rb        | 43 +++++++++++++++++++
 4 files changed, 81 insertions(+), 14 deletions(-)

diff --git a/Library/.rubocop.yml b/Library/.rubocop.yml
index dafb1221b7..21f123859b 100644
--- a/Library/.rubocop.yml
+++ b/Library/.rubocop.yml
@@ -15,6 +15,9 @@ FormulaAudit/Caveats:
 FormulaAudit/Checksum:
   Enabled: true
 
+FormulaAudit/ChecksumCase:
+  Enabled: true
+
 FormulaAuditStrict/BottleBlock:
   Enabled: true
 
diff --git a/Library/Homebrew/rubocops/checksum_cop.rb b/Library/Homebrew/rubocops/checksum_cop.rb
index d9e81a4eff..dcaf60e7d3 100644
--- a/Library/Homebrew/rubocops/checksum_cop.rb
+++ b/Library/Homebrew/rubocops/checksum_cop.rb
@@ -21,15 +21,6 @@ module RuboCop
           end
         end
 
-        def get_checksum_node(call)
-          return if parameters(call).empty? || parameters(call).nil?
-          if parameters(call).first.str_type?
-            parameters(call).first
-          elsif parameters(call).first.hash_type?
-            parameters(call).first.keys.first
-          end
-        end
-
         def audit_sha256(checksum)
           return if checksum.nil?
           if regex_match_group(checksum, /^$/)
@@ -41,12 +32,31 @@ module RuboCop
             problem "sha256 should be 64 characters"
           end
 
-          if regex_match_group(checksum, /[^a-f0-9]+/i)
-            problem "sha256 contains invalid characters"
-          end
+          return unless regex_match_group(checksum, /[^a-f0-9]+/i)
+          problem "sha256 contains invalid characters"
+        end
+      end
 
-          return unless regex_match_group(checksum, /[A-F]+/)
-          problem "sha256 should be lowercase"
+      class ChecksumCase < FormulaCop
+        def audit_formula(_node, _class_node, _parent_class_node, body_node)
+          return if body_node.nil?
+          sha256_calls = find_every_method_call_by_name(body_node, :sha256)
+          sha256_calls.each do |sha256_call|
+            checksum = get_checksum_node(sha256_call)
+            next if checksum.nil?
+            next unless regex_match_group(checksum, /[A-F]+/)
+            problem "sha256 should be lowercase"
+          end
+        end
+
+        private
+
+        def autocorrect(node)
+          lambda do |corrector|
+            correction = node.source.downcase
+            corrector.insert_before(node.source_range, correction)
+            corrector.remove(node.source_range)
+          end
         end
       end
     end
diff --git a/Library/Homebrew/rubocops/extend/formula_cop.rb b/Library/Homebrew/rubocops/extend/formula_cop.rb
index 98280841cc..439fde6a55 100644
--- a/Library/Homebrew/rubocops/extend/formula_cop.rb
+++ b/Library/Homebrew/rubocops/extend/formula_cop.rb
@@ -277,6 +277,17 @@ module RuboCop
         end
       end
 
+      # Returns the sha256 str node given a sha256 call node
+      def get_checksum_node(call)
+        return if parameters(call).empty? || parameters(call).nil?
+        if parameters(call).first.str_type?
+          parameters(call).first
+        # sha256 is passed as a key-value pair in bottle blocks
+        elsif parameters(call).first.hash_type?
+          parameters(call).first.keys.first
+        end
+      end
+
       # Returns the begin position of the node's line in source code
       def line_start_column(node)
         node.source_range.source_buffer.line_range(node.loc.line).begin_pos
diff --git a/Library/Homebrew/test/rubocops/checksum_cop_spec.rb b/Library/Homebrew/test/rubocops/checksum_cop_spec.rb
index 633f3117ac..644152c32c 100644
--- a/Library/Homebrew/test/rubocops/checksum_cop_spec.rb
+++ b/Library/Homebrew/test/rubocops/checksum_cop_spec.rb
@@ -108,7 +108,13 @@ describe RuboCop::Cop::FormulaAudit::Checksum do
         expect_offense(expected, actual)
       end
     end
+  end
+end
 
+describe RuboCop::Cop::FormulaAudit::ChecksumCase do
+  subject(:cop) { described_class.new }
+
+  context "When auditing spec checksums" do
     it "When the checksum has upper case characters" do
       source = <<-EOS.undent
         class Foo < Formula
@@ -176,4 +182,41 @@ describe RuboCop::Cop::FormulaAudit::Checksum do
       end
     end
   end
+
+  context "When auditing checksum with autocorrect" do
+    it "When there is uppercase sha256" do
+      source = <<-EOS.undent
+        class Foo < Formula
+          url 'http://example.com/foo-1.0.tgz'
+          stable do
+            url "https://github.com/foo-lang/foo-compiler/archive/0.18.0.tar.gz"
+            sha256 "5cf6e1ae0A645b426c0a7cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea0e9a"
+
+            resource "foo-package" do
+              url "https://github.com/foo-lang/foo-package/archive/0.18.0.tar.gz"
+              sha256 "5cf6e1Ae0a645b426b047aa4cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea9"
+            end
+          end
+        end
+      EOS
+
+      corrected_source = <<-EOS.undent
+        class Foo < Formula
+          url 'http://example.com/foo-1.0.tgz'
+          stable do
+            url "https://github.com/foo-lang/foo-compiler/archive/0.18.0.tar.gz"
+            sha256 "5cf6e1ae0a645b426c0a7cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea0e9a"
+
+            resource "foo-package" do
+              url "https://github.com/foo-lang/foo-package/archive/0.18.0.tar.gz"
+              sha256 "5cf6e1ae0a645b426b047aa4cc7cd3f7d1605ffa1ac5756a39a8b2268ddc7ea9"
+            end
+          end
+        end
+      EOS
+
+      new_source = autocorrect_source(cop, source)
+      expect(new_source).to eq(corrected_source)
+    end
+  end
 end