From 78065c57810214a7944d4849880fb5b67d3a5e38 Mon Sep 17 00:00:00 2001
From: Carlo Cabrera <30379873+carlocab@users.noreply.github.com>
Date: Wed, 25 Sep 2024 16:54:59 +0800
Subject: [PATCH] env_config: deprecate setting boolean vars to falsy values

The way we handle boolean environment variables is a bit unfortunate.
For example, setting `HOMEBREW_EVAL_ALL=false` actually enables
`HOMEBREW_EVAL_ALL`.

Let's fix this by deprecating setting boolean environment variables to
common false-y values (`false`, `0`, `nil`, `no`, and `off`) so that we
can later ignore these false-y values when reading boolean environment
variables.
---
 Library/Homebrew/env_config.rb                     | 13 ++++++++++++-
 Library/Homebrew/test/github_runner_matrix_spec.rb |  4 ++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/env_config.rb b/Library/Homebrew/env_config.rb
index 63445e6dbe..bb185001b3 100644
--- a/Library/Homebrew/env_config.rb
+++ b/Library/Homebrew/env_config.rb
@@ -515,7 +515,18 @@ module Homebrew
 
       if hash[:boolean]
         define_method(method_name) do
-          ENV[env].present?
+          env_value = ENV.fetch(env, nil)
+
+          falsy_values = %w[false no off nil 0]
+          if falsy_values.include?(env_value&.downcase)
+            odeprecated "#{env}=#{env_value}", <<~EOS
+              If you wish to enable #{env}, #{env}=1
+              If you wish to disable #{env}, #{env}=
+            EOS
+          end
+
+          # TODO: Uncomment the remaining part of the line below after the deprecation/disable cycle.
+          env_value.present? # && !falsy_values.include(env_value.downcase)
         end
       elsif hash[:default].present?
         define_method(method_name) do
diff --git a/Library/Homebrew/test/github_runner_matrix_spec.rb b/Library/Homebrew/test/github_runner_matrix_spec.rb
index 24f6e6221b..d314f3522b 100644
--- a/Library/Homebrew/test/github_runner_matrix_spec.rb
+++ b/Library/Homebrew/test/github_runner_matrix_spec.rb
@@ -9,6 +9,10 @@ RSpec.describe GitHubRunnerMatrix do
     allow(ENV).to receive(:fetch).with("HOMEBREW_MACOS_LONG_TIMEOUT", "false").and_return("false")
     allow(ENV).to receive(:fetch).with("HOMEBREW_MACOS_BUILD_ON_GITHUB_RUNNER", "false").and_return("false")
     allow(ENV).to receive(:fetch).with("GITHUB_RUN_ID").and_return("12345")
+    allow(ENV).to receive(:fetch).with("HOMEBREW_NO_INSTALL_FROM_API", nil).and_call_original
+    allow(ENV).to receive(:fetch).with("HOMEBREW_EVAL_ALL", nil).and_call_original
+    allow(ENV).to receive(:fetch).with("HOMEBREW_SIMULATE_MACOS_ON_LINUX", nil).and_call_original
+    allow(ENV).to receive(:fetch).with("HOMEBREW_FORBID_PACKAGES_FROM_PATHS", nil).and_call_original
   end
 
   let(:newest_supported_macos) do