Update cask rubocops to use on_arch blocks and sha256 arm:, intel:

Library/Homebrew/rubocops/cask/on_system_conditionals.rb

@@ -39,6 +39,9 @@ module RuboCop
 
             audit_on_system_blocks(stanza.stanza_node, stanza.stanza_name)
           end
+
+          audit_arch_conditionals(cask_body)
+          simplify_sha256_stanzas
         end
 
         private
@@ -46,6 +49,33 @@ module RuboCop
         attr_reader :cask_block
 
         def_delegators :cask_block, :toplevel_stanzas, :cask_body
+
+        def simplify_sha256_stanzas
+          nodes = {}
+
+          sha256_on_arch_stanzas(cask_body) do |node, method, value|
+            nodes[method.to_s.delete_prefix("on_").to_sym] = { node: node, value: value }
+          end
+
+          return if !nodes.key?(:arm) || !nodes.key?(:intel)
+
+          offending_node(nodes[:arm][:node])
+          replacement_string = "sha256 arm: #{nodes[:arm][:value].inspect}, intel: #{nodes[:intel][:value].inspect}"
+
+          problem "Use `#{replacement_string}` instead of nesting the `sha256` stanzas in " \
+                  "`on_intel` and `on_arm` blocks" do |corrector|
+            corrector.replace(nodes[:arm][:node].source_range, replacement_string)
+            corrector.replace(nodes[:intel][:node].source_range, "")
+          end
+        end
+
+        def_node_search :sha256_on_arch_stanzas, <<~PATTERN
+          $(block
+            (send nil? ${:on_intel :on_arm})
+            (args)
+            (send nil? :sha256
+              (str $_)))
+        PATTERN
       end
     end
   end

Library/Homebrew/rubocops/cask/on_system_conditionals.rbi

@@ -0,0 +1,17 @@
+# typed: strict
+
+module RuboCop
+  module Cop
+    module Cask
+      class OnSystemConditionals < Base
+        sig {
+          params(
+            base_node: Parser::AST::Node,
+            block:     T.proc.params(node: Parser::AST::Node, method: Symbol, value: String).void,
+          ).void
+        }
+        def sha256_on_arch_stanzas(base_node, &block); end
+      end
+    end
+  end
+end

Library/Homebrew/test/rubocops/cask/on_system_conditionals_spec.rb

@@ -13,8 +13,10 @@ describe RuboCop::Cop::Cask::OnSystemConditionals do
     context "when there are no on_system blocks" do
       let(:source) do
         <<-CASK.undent
-          postflight do
+          cask 'foo' do
-            foobar
+            postflight do
+              foobar
+            end
           end
         CASK
       end
@@ -137,4 +139,127 @@ describe RuboCop::Cop::Cask::OnSystemConditionals do
       include_examples "autocorrects source"
     end
   end
+
+  context "when auditing `sha256` stanzas inside on_arch blocks" do
+    context "when there are no on_arch blocks" do
+      let(:source) do
+        <<-CASK.undent
+          cask 'foo' do
+            sha256 "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"
+          end
+        CASK
+      end
+
+      include_examples "does not report any offenses"
+    end
+
+    context "when the proper `sha256` stanza is used" do
+      let(:source) do
+        <<-CASK.undent
+          cask 'foo' do
+            sha256 arm:   "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94",
+                   intel: "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
+          end
+        CASK
+      end
+
+      include_examples "does not report any offenses"
+    end
+
+    context "when the `sha256` stanza needs to be removed from the on_arch blocks" do
+      let(:source) do
+        <<-CASK.undent
+          cask 'foo' do
+            on_intel do
+              sha256 "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"
+            end
+            on_arm do
+              sha256 "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
+            end
+          end
+        CASK
+      end
+      let(:correct_source) do
+        <<-CASK.undent
+          cask 'foo' do
+          #{"  "}
+            sha256 arm: "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b", intel: "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"
+          end
+        CASK
+      end
+      let(:offense_source) do
+        <<-CASK.undent
+          on_arm do
+              sha256 "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
+            end
+        CASK
+      end
+      let(:expected_offenses) do
+        [{
+          message:  'Use `sha256 arm: "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b", ' \
+                    'intel: "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"` instead of ' \
+                    "nesting the `sha256` stanzas in `on_intel` and `on_arm` blocks",
+          severity: :convention,
+          line:     5,
+          column:   2,
+          source:   offense_source.strip,
+        }]
+      end
+
+      include_examples "reports offenses"
+
+      include_examples "autocorrects source"
+    end
+
+    context "when there is only one on_arch block" do
+      let(:source) do
+        <<-CASK.undent
+          cask 'foo' do
+            on_intel do
+              sha256 "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"
+            end
+          end
+        CASK
+      end
+
+      include_examples "does not report any offenses"
+    end
+
+    context "when there is also a `version` stanza inside the on_arch blocks" do
+      let(:source) do
+        <<-CASK.undent
+          cask 'foo' do
+            on_intel do
+              version "1.0.0"
+              sha256 "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"
+            end
+            on_arm do
+              version "2.0.0"
+              sha256 "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
+            end
+          end
+        CASK
+      end
+
+      include_examples "does not report any offenses"
+    end
+
+    context "when there is also a `version` stanza inside only a single on_arch block" do
+      let(:source) do
+        <<-CASK.undent
+          cask 'foo' do
+            on_intel do
+              version "2.0.0"
+              sha256 "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"
+            end
+            on_arm do
+              sha256 "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
+            end
+          end
+        CASK
+      end
+
+      include_examples "does not report any offenses"
+    end
+  end
 end