Improve completions (and elisp) output in caveats

Instead of repeatedly outputting the same identical messages across
multiple packages and repeating them all for every package after they
were all installed: just output the identical messages in the final
caveats output instead.

Library/Homebrew/caveats.rb

@@ -14,40 +14,54 @@ class Caveats
   sig { params(formula: Formula).void }
   def initialize(formula)
     @formula = formula
+    @caveats = T.let(nil, T.nilable(String))
+    @completions_and_elisp = T.let(nil, T.nilable(T::Array[String]))
   end
 
   sig { returns(String) }
   def caveats
-    caveats = []
-    build = formula.build
-    begin
-      formula.build = Tab.for_formula(formula)
-      string = formula.caveats.to_s
-      caveats << "#{string.chomp}\n" unless string.empty?
-    ensure
-      formula.build = build
+    @caveats ||= begin
+      caveats = []
+      build = formula.build
+      begin
+        formula.build = Tab.for_formula(formula)
+        string = formula.caveats.to_s
+        caveats << "#{string.chomp}\n" unless string.empty?
+      ensure
+        formula.build = build
+      end
+      caveats << keg_only_text
+      caveats << service_caveats
+      caveats.compact.join("\n")
     end
-    caveats << keg_only_text
-
-    valid_shells = [:bash, :zsh, :fish, :pwsh].freeze
-    current_shell = Utils::Shell.preferred || Utils::Shell.parent
-    shells = if current_shell.present? &&
-                (shell_sym = current_shell.to_sym) &&
-                valid_shells.include?(shell_sym)
-      [shell_sym]
-    else
-      valid_shells
-    end
-    shells.each do |shell|
-      caveats << function_completion_caveats(shell)
-    end
-
-    caveats << service_caveats
-    caveats << elisp_caveats
-    caveats.compact.join("\n")
   end
 
-  delegate [:empty?, :to_s] => :caveats
+  sig { returns(T::Boolean) }
+  def empty?
+    caveats.blank? && completions_and_elisp.blank?
+  end
+
+  delegate [:to_s] => :caveats
+
+  sig { returns(T::Array[String]) }
+  def completions_and_elisp
+    @completions_and_elisp ||= begin
+      valid_shells = [:bash, :zsh, :fish, :pwsh].freeze
+      current_shell = Utils::Shell.preferred || Utils::Shell.parent
+      shells = if current_shell.present? &&
+                  (shell_sym = current_shell.to_sym) &&
+                  valid_shells.include?(shell_sym)
+        [shell_sym]
+      else
+        valid_shells
+      end
+      completions_and_elisp = shells.map do |shell|
+        function_completion_caveats(shell)
+      end
+      completions_and_elisp << elisp_caveats
+      completions_and_elisp.compact
+    end
+  end
 
   sig { params(skip_reason: T::Boolean).returns(T.nilable(String)) }
   def keg_only_text(skip_reason: false)

Library/Homebrew/formula_installer.rb

@@ -892,9 +892,11 @@ on_request: installed_on_request?, options:)
     return if quiet?
 
     caveats = Caveats.new(formula)
-
     return if caveats.empty?
 
+    Homebrew.messages.record_completions_and_elisp(caveats.completions_and_elisp)
+    return if caveats.caveats.empty?
+
     @show_summary_heading = true
     ohai "Caveats", caveats.to_s
     Homebrew.messages.record_caveats(formula.name, caveats)

Library/Homebrew/messages.rb

@@ -16,6 +16,7 @@ class Messages
   sig { void }
   def initialize
     @caveats = T.let([], T::Array[T::Hash[Symbol, Symbol]])
+    @completions_and_elisp = T.let(Set.new, T::Set[String])
     @package_count = T.let(0, Integer)
     @install_times = T.let([], T::Array[T::Hash[String, Float]])
   end
@@ -25,6 +26,11 @@ class Messages
     @caveats.push(package:, caveats:)
   end
 
+  sig { params(completions_and_elisp: T::Array[String]).void }
+  def record_completions_and_elisp(completions_and_elisp)
+    @completions_and_elisp.merge(completions_and_elisp)
+  end
+
   sig { params(package: String, elapsed_time: Float).void }
   def package_installed(package, elapsed_time)
     @package_count += 1
@@ -40,13 +46,14 @@ class Messages
   sig { params(force: T::Boolean).void }
   def display_caveats(force: false)
     return if @package_count.zero?
-    return if @package_count == 1 && !force
-    return if @caveats.empty?
+    return if @caveats.empty? && @completions_and_elisp.empty?
 
-    oh1 "Caveats"
-    @caveats.each do |c|
-      ohai c[:package], c[:caveats]
-    end
+    oh1 "Caveats" unless @completions_and_elisp.empty?
+    @completions_and_elisp.each { |c| puts c }
+    return if @package_count == 1 && !force
+
+    oh1 "Caveats" if @completions_and_elisp.empty?
+    @caveats.each { |c| ohai c[:package], c[:caveats] }
   end
 
   sig { void }

Library/Homebrew/sorbet/rbi/dsl/caveats.rbi

@@ -6,9 +6,6 @@
 
 
 class Caveats
-  sig { params(args: T.untyped, block: T.untyped).returns(T::Boolean) }
-  def empty?(*args, &block); end
-
   sig { params(args: T.untyped, block: T.untyped).returns(String) }
   def to_s(*args, &block); end
 end

Library/Homebrew/test/caveats_spec.rb

@@ -242,7 +242,7 @@ RSpec.describe Caveats do
           url "foo-1.0"
         end
       end
-      let(:caveats) { described_class.new(f).caveats }
+      let(:caveats) { described_class.new(f) }
       let(:path) { f.prefix.resolved_path }
 
       let(:bash_completion_dir) { path/"etc/bash_completion.d" }
@@ -261,25 +261,25 @@ RSpec.describe Caveats do
       it "includes where Bash completions have been installed to" do
         bash_completion_dir.mkpath
         FileUtils.touch bash_completion_dir/f.name
-        expect(caveats).to include(HOMEBREW_PREFIX/"etc/bash_completion.d")
+        expect(caveats.completions_and_elisp.join).to include(HOMEBREW_PREFIX/"etc/bash_completion.d")
       end
 
       it "includes where fish completions have been installed to" do
         fish_vendor_completions.mkpath
         FileUtils.touch fish_vendor_completions/f.name
-        expect(caveats).to include(HOMEBREW_PREFIX/"share/fish/vendor_completions.d")
+        expect(caveats.completions_and_elisp.join).to include(HOMEBREW_PREFIX/"share/fish/vendor_completions.d")
       end
 
       it "includes where zsh completions have been installed to" do
         zsh_site_functions.mkpath
         FileUtils.touch zsh_site_functions/f.name
-        expect(caveats).to include(HOMEBREW_PREFIX/"share/zsh/site-functions")
+        expect(caveats.completions_and_elisp.join).to include(HOMEBREW_PREFIX/"share/zsh/site-functions")
       end
 
       it "includes where pwsh completions have been installed to" do
         pwsh_completion_dir.mkpath
         FileUtils.touch pwsh_completion_dir/f.name
-        expect(caveats).to include(HOMEBREW_PREFIX/"share/pwsh/completions")
+        expect(caveats.completions_and_elisp.join).to include(HOMEBREW_PREFIX/"share/pwsh/completions")
       end
     end
   end