Add which entry command

Library/Homebrew/cmd/tab.rb

@@ -78,6 +78,7 @@ def update_tab(formula_or_cask, installed_on_request:)
         end
 
         tab.installed_on_request = installed_on_request
+        tab.installed_as_dependency = !installed_on_request if formula_or_cask.is_a?(Formula)
         tab.write
         ohai "#{name} is now marked as #{installed_on_request_str}."
       end

Library/Homebrew/dev-cmd/which-entry.rb

@@ -0,0 +1,83 @@
+# typed: strict
+# frozen_string_literal: true
+
+require "abstract_command"
+require "formula"
+require "formulary"
+require "json"
+
+module Homebrew
+  module DevCmd
+    class WhichEntry < AbstractCommand
+      cmd_args do
+        description <<~EOS
+          Generate an `executables.txt` entry for <formula> using bottle manifest metadata.
+        EOS
+        flag "--output-db=",
+             description: "Append or update the entry in the given `executables.txt` database file."
+        named_args :formula, min: 1
+      end
+
+      sig { override.void }
+      def run
+        db_path = Pathname(T.unsafe(args).output_db) if T.unsafe(args).output_db
+        args.named.each { |name| process(name, db_path:) }
+      end
+
+      private
+
+      sig { params(name: String, db_path: T.nilable(Pathname)).void }
+      def process(name, db_path:)
+        formula = Formulary.factory(name)
+        line = db_line(formula)
+        if db_path
+          write_db(db_path, formula.full_name, line)
+        elsif line
+          puts line
+        end
+      rescue FormulaUnavailableError
+        write_db(db_path, name, nil) if db_path&.exist?
+      end
+
+      sig { params(db_path: Pathname, name: String, line: T.nilable(String)).void }
+      def write_db(db_path, name, line)
+        lines = db_path.readlines(chomp: true).compact_blank if db_path.exist?
+        lines = (lines || []).reject { |l| l.start_with?("#{name}(") }
+        lines << line if line
+        db_path.write("#{lines.sort.join("\n")}\n")
+      end
+
+      sig { params(formula: Formula).returns(T.nilable(String)) }
+      def db_line(formula)
+        return if formula.disabled? || formula.deprecated?
+
+        exes = executables_from_manifest(formula)
+        "#{formula.full_name}(#{formula.pkg_version}):#{exes.join(" ")}"
+      end
+
+      sig { params(formula: Formula).returns(T::Array[String]) }
+      def executables_from_manifest(formula)
+        return [] unless formula.bottled?
+
+        manifest_path = HOMEBREW_CACHE.glob("#{formula.name}_bottle_manifest--*").first
+        if manifest_path.blank?
+          bottle = formula.bottle
+          return [] unless bottle
+
+          bottle.fetch
+          manifest_path = HOMEBREW_CACHE.glob("#{formula.name}_bottle_manifest--*").first
+        end
+        return [] if manifest_path.blank?
+
+        manifest = JSON.parse(manifest_path.read)
+        exec_files = manifest.dig("manifests", 0, "annotations", "sh.brew.path_exec_files")
+        return [] if exec_files.blank?
+
+        exec_files.split.map { |f| File.basename(f) }.sort
+      rescue JSON::ParserError => e
+        opoo "Failed to parse bottle manifest for #{formula.name}: #{e.message}"
+        []
+      end
+    end
+  end
+end

Library/Homebrew/test/dev-cmd/which-entry_spec.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+require "cmd/shared_examples/args_parse"
+require "dev-cmd/which-entry"
+
+RSpec.describe Homebrew::DevCmd::WhichEntry do
+  it_behaves_like "parseable arguments"
+end