utils: add method ensure_formula_installed!

Library/Homebrew/dev-cmd/bottle.rb

@@ -108,10 +108,7 @@ module Homebrew
 
   def ensure_relocation_formulae_installed!
     Keg.relocation_formulae.each do |f|
-      next if Formula[f].latest_version_installed?
+      ensure_formula_installed!(f, latest: true)
-
-      ohai "Installing #{f}..."
-      safe_system HOMEBREW_BREW_FILE, "install", f
     end
   end
 
@@ -263,10 +260,7 @@ module Homebrew
       return default_tar_args
     end
 
-    unless gnu_tar.any_version_installed?
+    ensure_formula_installed!(gnu_tar, "for bottling")
-      ohai "Installing `gnu-tar` for bottling..."
-      safe_system HOMEBREW_BREW_FILE, "install", "--formula", gnu_tar.full_name
-    end
 
     ["#{gnu_tar.opt_bin}/gtar", gnutar_args].freeze
   end

Library/Homebrew/dev-cmd/bump.rb

@@ -59,8 +59,7 @@ module Homebrew
     unless Utils::Curl.curl_supports_tls13?
       begin
         unless Pathname.new(ENV["HOMEBREW_BREWED_CURL_PATH"]).exist?
-          ohai "Installing `curl` for Repology queries..."
+          ensure_formula_installed!("curl", "for Repology queries")
-          safe_system HOMEBREW_BREW_FILE, "install", "--formula", Formula["curl"].full_name
         end
       rescue FormulaUnavailableError
         opoo "A `curl` with TLS 1.3 support is required for Repology queries."

Library/Homebrew/dev-cmd/cat.rb

@@ -31,18 +31,14 @@ module Homebrew
 
     cd HOMEBREW_REPOSITORY
     pager = if Homebrew::EnvConfig.bat?
-      require "formula"
+      ENV["BAT_CONFIG_PATH"] = Homebrew::EnvConfig.bat_config_path
-
+      ensure_formula_installed!(
-      unless Formula["bat"].any_version_installed?
+        "bat",
+        "for displaying <formula>/<cask> source",
         # The user might want to capture the output of `brew cat ...`
         # Redirect stdout to stderr
-        redirect_stdout($stderr) do
+        output_to_stderr: true,
-          ohai "Installing `bat` for displaying <formula>/<cask> source..."
+      ).opt_bin/"bat"
-          safe_system HOMEBREW_BREW_FILE, "install", "bat"
-        end
-      end
-      ENV["BAT_CONFIG_PATH"] = Homebrew::EnvConfig.bat_config_path
-      Formula["bat"].opt_bin/"bat"
     else
       "cat"
     end

Library/Homebrew/dev-cmd/tests.rb

@@ -48,11 +48,9 @@ module Homebrew
   def run_buildpulse
     require "formula"
 
-    unless Formula["buildpulse-test-reporter"].any_version_installed?
+    with_env(HOMEBREW_NO_AUTO_UPDATE: "1", HOMEBREW_NO_BOOTSNAP: "1") do
-      ohai "Installing `buildpulse-test-reporter` for reporting test flakiness..."
+      ensure_formula_installed!("buildpulse-test-reporter",
-      with_env(HOMEBREW_NO_AUTO_UPDATE: "1", HOMEBREW_NO_BOOTSNAP: "1") do
+                                "for reporting test flakiness")
-        safe_system HOMEBREW_BREW_FILE, "install", "buildpulse-test-reporter"
-      end
     end
 
     ENV["BUILDPULSE_ACCESS_KEY_ID"] = ENV["HOMEBREW_BUILDPULSE_ACCESS_KEY_ID"]

Library/Homebrew/github_packages.rb

@@ -53,11 +53,7 @@ class GitHubPackages
       which("skopeo", ENV["HOMEBREW_PATH"]),
       HOMEBREW_PREFIX/"bin/skopeo",
     ].compact.first
-    unless skopeo.exist?
+    skopeo = ensure_formula_installed!("skopeo", "for upload").opt_bin/"skopeo" unless skopeo.exist?
-      ohai "Installing `skopeo` for upload..."
-      safe_system HOMEBREW_BREW_FILE, "install", "--formula", "skopeo"
-      skopeo = Formula["skopeo"].opt_bin/"skopeo"
-    end
 
     require "json_schemer"
 

Library/Homebrew/style.rb

@@ -278,31 +278,12 @@ module Homebrew
 
     def shellcheck
       # Always use the latest brewed shellcheck
-      unless Formula["shellcheck"].latest_version_installed?
+      ensure_formula_installed!("shellcheck", "for shell style checks", latest: true).opt_bin/"shellcheck"
-        if Formula["shellcheck"].any_version_installed?
-          ohai "Upgrading `shellcheck` for shell style checks..."
-          safe_system HOMEBREW_BREW_FILE, "upgrade", "shellcheck"
-        else
-          ohai "Installing `shellcheck` for shell style checks..."
-          safe_system HOMEBREW_BREW_FILE, "install", "shellcheck"
-        end
-      end
-
-      Formula["shellcheck"].opt_bin/"shellcheck"
     end
 
     def shfmt
       # Always use the latest brewed shfmt
-      unless Formula["shfmt"].latest_version_installed?
+      ensure_formula_installed!("shfmt", "to format shell scripts", latest: true)
-        if Formula["shfmt"].any_version_installed?
-          ohai "Upgrading `shfmt` to format shell scripts..."
-          safe_system HOMEBREW_BREW_FILE, "upgrade", "shfmt"
-        else
-          ohai "Installing `shfmt` to format shell scripts..."
-          safe_system HOMEBREW_BREW_FILE, "install", "shfmt"
-        end
-      end
-
       HOMEBREW_LIBRARY/"Homebrew/utils/shfmt.sh"
     end
 

Library/Homebrew/utils.rb

@@ -454,6 +454,47 @@ module Kernel
     out.close
   end
 
+  # Ensure the given formula is installed
+  # This is useful for installing a utility formula (e.g. `shellcheck` for `brew style`)
+  def ensure_formula_installed!(formula_or_name, reason = "", latest: false, linked: false,
+                                output_to_stderr: false, quiet: false)
+    if output_to_stderr || quiet
+      file = if quiet
+        File::NULL
+      else
+        $stderr
+      end
+      # Call this method itself with redirected stdout
+      redirect_stdout(file) do
+        return ensure_formula_installed!(formula_or_name, reason, latest: latest, linked: linked)
+      end
+    end
+
+    require "formula"
+
+    formula = if formula_or_name.is_a?(Formula)
+      formula_or_name
+    else
+      Formula[formula_or_name]
+    end
+
+    reason = " #{reason}" if reason.present? # add a whitespace
+
+    unless formula.any_version_installed?
+      ohai "Installing `#{formula.name}`#{reason}..."
+      safe_system HOMEBREW_BREW_FILE, "install", "--formula", formula.full_name
+    end
+
+    if latest && !formula.latest_version_installed?
+      ohai "Upgrading `#{formula.name}`#{reason}..."
+      safe_system HOMEBREW_BREW_FILE, "upgrade", "--formula", formula.full_name
+    end
+
+    safe_system HOMEBREW_BREW_FILE, "link", formula.full_name if linked && !formula.linked?
+
+    formula
+  end
+
   def paths
     @paths ||= PATH.new(ENV["HOMEBREW_PATH"]).map do |p|
       File.expand_path(p).chomp("/")

Library/Homebrew/utils/git.rb

@@ -100,7 +100,7 @@ module Utils
           # and will also likely fail due to `OS::Linux` and `OS::Mac` being undefined.
           raise "Refusing to install Git on a generic OS." if ENV["HOMEBREW_TEST_GENERIC_OS"]
 
-          safe_system HOMEBREW_BREW_FILE, "install", "git"
+          ensure_formula_installed!("git")
           clear_available_cache
         rescue
           raise "Git is unavailable"