From 0a3ad268a0d81df7bc8ecc5c945dd7a29f2bd842 Mon Sep 17 00:00:00 2001
From: commitay <commitay@users.noreply.github.com>
Date: Sun, 26 Aug 2018 13:57:21 +1000
Subject: [PATCH] audit: check versioned formulae for `keg_only
 :versioned_formula`

---
 Library/Homebrew/dev-cmd/audit.rb           | 19 +++++++++
 Library/Homebrew/test/dev-cmd/audit_spec.rb | 44 +++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 278ec1382c..a33b4c05fb 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -525,6 +525,25 @@ module Homebrew
       problem "keg_only reason should not end with a period."
     end
 
+    def audit_versioned_keg_only
+      return unless formula.versioned_formula?
+      return unless @core_tap
+
+      return if formula.keg_only? && formula.keg_only_reason.reason == :versioned_formula
+
+      keg_only_whitelist = %w[
+        autoconf@2.13
+        bash-completion@2
+        gnupg@1.4
+        lua@5.1
+        python@2
+      ].freeze
+
+      return if keg_only_whitelist.include?(formula.name) || formula.name.start_with?("gcc@")
+
+      problem "Versioned formulae should use `keg_only :versioned_formula`"
+    end
+
     def audit_homepage
       homepage = formula.homepage
 
diff --git a/Library/Homebrew/test/dev-cmd/audit_spec.rb b/Library/Homebrew/test/dev-cmd/audit_spec.rb
index f9953d563f..fbcc79498f 100644
--- a/Library/Homebrew/test/dev-cmd/audit_spec.rb
+++ b/Library/Homebrew/test/dev-cmd/audit_spec.rb
@@ -600,5 +600,49 @@ module Homebrew
         expect(fa.problems).to eq([])
       end
     end
+
+    describe "#audit_versioned_keg_only" do
+      specify "it warns when a versioned formula is not `keg_only`" do
+        fa = formula_auditor "foo@1.1", <<~RUBY, core_tap: true
+          class FooAT11 < Formula
+            url "https://example.com/foo-1.1.tgz"
+          end
+        RUBY
+
+        fa.audit_versioned_keg_only
+
+        expect(fa.problems.first)
+          .to match("Versioned formulae should use `keg_only :versioned_formula`")
+      end
+
+      specify "it warns when a versioned formula has an incorrect `keg_only` reason" do
+        fa = formula_auditor "foo@1.1", <<~RUBY, core_tap: true
+          class FooAT11 < Formula
+            url "https://example.com/foo-1.1.tgz"
+
+            keg_only :provided_by_macos
+          end
+        RUBY
+
+        fa.audit_versioned_keg_only
+
+        expect(fa.problems.first)
+          .to match("Versioned formulae should use `keg_only :versioned_formula`")
+      end
+
+      specify "it does not warn when a versioned formula has `keg_only :versioned_formula`" do
+        fa = formula_auditor "foo@1.1", <<~RUBY, core_tap: true
+          class FooAT11 < Formula
+            url "https://example.com/foo-1.1.tgz"
+
+            keg_only :versioned_formula
+          end
+        RUBY
+
+        fa.audit_versioned_keg_only
+
+        expect(fa.problems).to eq([])
+      end
+    end
   end
 end