Re-add on_arch_conditional DSL

Library/Homebrew/cask/dsl.rb

@@ -250,14 +250,7 @@ module Cask
       set_unique_stanza(:arch, should_return) do
         @on_system_blocks_exist = true
 
-        # If arm and intel are arrays and one isn't specified, default to an array that is the same size as the other
+        on_arch_conditional(arm: arm, intel: intel)
-        empty_value = Array.new(arm&.count || intel&.count) if arm.is_a?(Array) || intel.is_a?(Array)
-
-        if OnSystem.arch_condition_met? :arm
-          arm || empty_value
-        elsif OnSystem.arch_condition_met? :intel
-          intel || empty_value
-        end
       end
     end
 

Library/Homebrew/extend/on_system.rb

@@ -65,6 +65,13 @@ module OnSystem
         result
       end
     end
+
+    base.define_method(:on_arch_conditional) do |arm:, intel:|
+      @on_system_blocks_exist = true
+
+      return arm if OnSystem.arch_condition_met? :arm
+      return intel if OnSystem.arch_condition_met? :intel
+    end
   end
 
   sig { params(base: Class).void }

Library/Homebrew/test/cask/cask_spec.rb

@@ -218,25 +218,25 @@ describe Cask::Cask, :cask do
       <<~JSON
         {
           "arm64_big_sur": {
-            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.2.0/arm.zip",
+            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/darwin-arm64/1.2.0/arm.zip",
             "version": "1.2.0",
             "sha256": "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
           },
           "monterey": {
-            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.2.3/intel.zip"
+            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/darwin/1.2.3/intel.zip"
           },
           "big_sur": {
-            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.2.0/intel.zip",
+            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/darwin/1.2.3/intel.zip",
             "version": "1.2.0",
             "sha256": "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
           },
           "catalina": {
-            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.0.0/intel.zip",
+            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/darwin/1.2.3/intel.zip",
             "version": "1.0.0",
             "sha256": "1866dfa833b123bb8fe7fa7185ebf24d28d300d0643d75798bc23730af734216"
           },
           "mojave": {
-            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.0.0/intel.zip",
+            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/darwin/1.2.3/intel.zip",
             "version": "1.0.0",
             "sha256": "1866dfa833b123bb8fe7fa7185ebf24d28d300d0643d75798bc23730af734216"
           }

Library/Homebrew/test/cask/cmd/list_spec.rb

@@ -160,7 +160,7 @@ describe Cask::Cmd::List, :cask do
             ],
             "desc": null,
             "homepage": "https://brew.sh/",
-            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.2.3/arm.zip",
+            "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/darwin-arm64/1.2.3/arm.zip",
             "appcast": null,
             "version": "1.2.3",
             "versions": {

Library/Homebrew/test/cask/dsl_spec.rb

@@ -312,8 +312,8 @@ describe Cask::DSL, :cask do
       expect { cask }.to raise_error(Cask::CaskInvalidError, /'arch' stanza may only appear once/)
     end
 
-    context "when only one string value is passed for intel" do
+    context "when no intel value is specified" do
-      let(:token) { "one-string-arch" }
+      let(:token) { "arch-arm-only" }
 
       context "when running on arm" do
         before do
@@ -335,30 +335,6 @@ describe Cask::DSL, :cask do
         end
       end
     end
-
-    context "when only one array arch value is passed for intel" do
-      let(:token) { "one-array-arch" }
-
-      context "when running on arm" do
-        before do
-          allow(Hardware::CPU).to receive(:type).and_return(:arm)
-        end
-
-        it "defaults to an array of the same size as the other when an array is passed" do
-          expect(cask.url.to_s).to eq "file://#{TEST_FIXTURE_DIR}/cask/caffeine.zip"
-        end
-      end
-
-      context "when running on intel" do
-        before do
-          allow(Hardware::CPU).to receive(:type).and_return(:intel)
-        end
-
-        it "returns the value" do
-          expect(cask.url.to_s).to eq "file://#{TEST_FIXTURE_DIR}/cask/intel-caffeine-x86_64.zip"
-        end
-      end
-    end
   end
 
   describe "appcast stanza" do

Library/Homebrew/test/support/fixtures/cask/Casks/arch-arm-only.rb

@@ -1,4 +1,4 @@
-cask "one-string-arch" do
+cask "arch-arm-only" do
   version "1.2.3"
   sha256 "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"
   arch arm: "-arm"

Library/Homebrew/test/support/fixtures/cask/Casks/multiple-versions.rb

@@ -3,6 +3,8 @@ cask "multiple-versions" do
   sha256 "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"
   arch arm: "arm", intel: "intel"
 
+  platform = on_arch_conditional arm: "darwin-arm64", intel: "darwin"
+
   on_big_sur do
     version "1.2.0"
     sha256 "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
@@ -13,7 +15,7 @@ cask "multiple-versions" do
     sha256 "1866dfa833b123bb8fe7fa7185ebf24d28d300d0643d75798bc23730af734216"
   end
 
-  url "file://#{TEST_FIXTURE_DIR}/cask/caffeine/#{version}/#{arch}.zip"
+  url "file://#{TEST_FIXTURE_DIR}/cask/caffeine/#{platform}/#{version}/#{arch}.zip"
   homepage "https://brew.sh/"
 
   app "Caffeine.app"

Library/Homebrew/test/support/fixtures/cask/Casks/one-array-arch.rb

@@ -1,10 +0,0 @@
-cask "one-array-arch" do
-  version "1.2.3"
-  sha256 "67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94"
-  arch intel: ["intel-", "-x86_64"]
-
-  url "file://#{TEST_FIXTURE_DIR}/cask/#{arch.first}caffeine#{arch.last}.zip"
-  homepage "https://brew.sh/"
-
-  app "Caffeine.app"
-end