formula: allow excluding deprecate! reason when disable! exists

Author: cho-m

Library/Homebrew/formula.rb

@@ -4237,12 +4237,10 @@ def pour_bottle?(only_if: nil, &block)
     # @see https://docs.brew.sh/Deprecating-Disabling-and-Removing-Formulae
     # @see DeprecateDisable::FORMULA_DEPRECATE_DISABLE_REASONS
     # @api public
-    def deprecate!(date:, because:)
+    def deprecate!(date:, because: nil)
       @deprecation_date = Date.parse(date)
-      return if @deprecation_date > Date.today
-
-      @deprecation_reason = because
-      @deprecated = true
+      @deprecated = !disabled? && @deprecation_date <= Date.today
+      @deprecation_reason = @deprecated ? (because || @deprecation_reason) : nil
     end
 
     # Whether this {Formula} is deprecated (i.e. warns on installation).

Library/Homebrew/rubocops/deprecate_disable.rb

@@ -45,8 +45,9 @@ class DeprecateDisableReason < FormulaCop
         sig { override.params(formula_nodes: FormulaNodes).void }
         def audit_formula(formula_nodes)
           body_node = formula_nodes.body_node
+          any_reason_found = T.let(false, T::Boolean)
 
-          [:deprecate!, :disable!].each do |method|
+          [:disable!, :deprecate!].each do |method|
             node = find_node_method_by_name(body_node, method)
 
             next if node.nil?
@@ -72,7 +73,7 @@ def audit_formula(formula_nodes)
               end
             end
 
-            next if reason_found
+            next if any_reason_found ||= reason_found
 
             case method
             when :deprecate!

Library/Homebrew/test/rubocops/deprecate_disable/reason_spec.rb

@@ -324,4 +324,16 @@ class Foo < Formula
       RUBY
     end
   end
+
+  context "when auditing `deprecate!` and `disable!`" do
+    it "reports no offense if `reason` exists on `deprecate!` but is absent on `disable!`" do
+      expect_no_offenses(<<~RUBY)
+        class Foo < Formula
+          url 'https://brew.sh/foo-1.0.tgz'
+          disable! date: "2021-08-28", because: :does_not_build
+          deprecate! date: "2020-08-28"
+        end
+      RUBY
+    end
+  end
 end