Deprecate #plural.

Library/Homebrew/compat/utils.rb

@@ -21,3 +21,8 @@ def puts_columns(items)
   odeprecated "puts_columns", "puts Formatter.columns"
   puts Formatter.columns(items)
 end
+
+def plural(n, s = "s")
+  odeprecated "#plural", "Formatter.pluralize"
+  n == 1 ? "" : s
+end

Library/Homebrew/test/utils_spec.rb

@@ -219,13 +219,6 @@ describe "globally-scoped helper methods" do
     end
   end
 
-  specify "#plural" do
-    expect(plural(1)).to eq("")
-    expect(plural(0)).to eq("s")
-    expect(plural(42)).to eq("s")
-    expect(plural(42, "")).to eq("")
-  end
-
   specify "#disk_usage_readable" do
     expect(disk_usage_readable(1)).to eq("1B")
     expect(disk_usage_readable(1000)).to eq("1000B")

Library/Homebrew/utils.rb

@@ -139,10 +139,6 @@ def pretty_duration(s)
   res << Formatter.pluralize(s, "second")
 end
 
-def plural(n, s = "s")
-  n == 1 ? "" : s
-end
-
 def interactive_shell(f = nil)
   unless f.nil?
     ENV["HOMEBREW_DEBUG_PREFIX"] = f.prefix

Library/Homebrew/utils/formatter.rb

@@ -96,11 +96,9 @@ module Formatter
 
     *adjectives, noun = singular.split(" ")
 
-    if plural.nil?
+    plural ||= {
-      plural = {
+      "formula" => "formulae",
-        "formula" => "formulae",
+    }.fetch(noun, "#{noun}s")
-      }.fetch(noun, "#{noun}s")
-    end
 
     words = adjectives << plural