From 32b68838f9e5518d5b5dff64f183e942744c63cc Mon Sep 17 00:00:00 2001
From: Max Eisner <4730112+max-ae@users.noreply.github.com>
Date: Wed, 13 Jul 2022 14:11:17 +0200
Subject: [PATCH] switch to more flexible shell_prefix arg

---
 Library/Homebrew/formula.rb | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 6353483f21..4de200ddeb 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1635,13 +1635,14 @@ class Formula
   # @param shell_as_flag [Boolean] specify if `shells` should each be passed as flags to the `binary`.
   # Defaults to `false`.
   sig {
-    params(base_name: String, shells: T::Array[Symbol], binary: Pathname, cmd: String, shell_as_flag: T::Boolean).void
+    params(base_name: String, shells: T::Array[Symbol], binary: Pathname, cmd: String,
+           shell_prefix: T.nilable(T.any(Symbol, String))).void
   }
   def generate_completions(base_name: name,
                            shells: [:bash, :zsh, :fish],
                            binary: bin/base_name,
                            cmd: "completion",
-                           shell_as_flag: false)
+                           shell_prefix: nil)
     completion_script_path_map = {
       bash: bash_completion/base_name,
       zsh:  zsh_completion/"_#{base_name}",
@@ -1650,7 +1651,14 @@ class Formula
 
     shells.each do |shell|
       script_path = completion_script_path_map[shell]
-      shell_parameter = shell_as_flag ? "--#{shell}" : shell.to_s
+      shell_parameter = if shell_prefix.nil?
+        shell.to_s
+      elsif shell_prefix == :flag
+        "--#{shell}"
+      else
+        "#{shell_prefix}#{shell}"
+      end
+
       script_path.dirname.mkpath
       script_path.write Utils.safe_popen_read(binary, cmd, shell_parameter)
     end