From 34a1bc66188f94caeb830a282b78a0ac7132f098 Mon Sep 17 00:00:00 2001
From: Rylan Polster <rslpolster@gmail.com>
Date: Sat, 23 Jul 2022 02:58:50 +0200
Subject: [PATCH] Use `SimulateSystem` for `ignore_missing_libraries`

---
 Library/Homebrew/extend/os/linux/formula.rb | 13 ------
 Library/Homebrew/formula.rb                 | 13 ++++--
 Library/Homebrew/test/formula_spec.rb       | 48 +++++++++++++++++++++
 3 files changed, 58 insertions(+), 16 deletions(-)

diff --git a/Library/Homebrew/extend/os/linux/formula.rb b/Library/Homebrew/extend/os/linux/formula.rb
index da2d162bdf..f3586103bc 100644
--- a/Library/Homebrew/extend/os/linux/formula.rb
+++ b/Library/Homebrew/extend/os/linux/formula.rb
@@ -23,17 +23,4 @@ class Formula
 
   sig { params(targets: T.nilable(T.any(Pathname, String))).void }
   def deuniversalize_machos(*targets); end
-
-  class << self
-    undef ignore_missing_libraries
-
-    def ignore_missing_libraries(*libs)
-      libraries = libs.flatten
-      if libraries.any? { |x| !x.is_a?(String) && !x.is_a?(Regexp) }
-        raise FormulaSpecificationError, "#{__method__} can handle Strings and Regular Expressions only"
-      end
-
-      allowed_missing_libraries.merge(libraries)
-    end
-  end
 end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index f52caa3650..1f842d6aaa 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -3214,10 +3214,17 @@ class Formula
     end
 
     # Permit links to certain libraries that don't exist. Available on Linux only.
-    def ignore_missing_libraries(*)
-      return if Homebrew::SimulateSystem.linux?
+    def ignore_missing_libraries(*libs)
+      unless Homebrew::SimulateSystem.treat_as_linux?
+        raise FormulaSpecificationError, "#{__method__} is available on Linux only"
+      end
 
-      raise FormulaSpecificationError, "#{__method__} is available on Linux only"
+      libraries = libs.flatten
+      if libraries.any? { |x| !x.is_a?(String) && !x.is_a?(Regexp) }
+        raise FormulaSpecificationError, "#{__method__} can handle Strings and Regular Expressions only"
+      end
+
+      allowed_missing_libraries.merge(libraries)
     end
 
     # @private
diff --git a/Library/Homebrew/test/formula_spec.rb b/Library/Homebrew/test/formula_spec.rb
index d4680abd7f..0883985623 100644
--- a/Library/Homebrew/test/formula_spec.rb
+++ b/Library/Homebrew/test/formula_spec.rb
@@ -1845,4 +1845,52 @@ describe Formula do
       expect(f.test).to eq(2)
     end
   end
+
+  describe "#ignore_missing_libraries" do
+    after do
+      Homebrew::SimulateSystem.clear
+    end
+
+    it "adds library to allowed_missing_libraries on Linux", :needs_linux do
+      Homebrew::SimulateSystem.clear
+      f = formula do
+        url "foo-1.0"
+
+        ignore_missing_libraries "bar.so"
+      end
+      expect(f.class.allowed_missing_libraries.to_a).to eq(["bar.so"])
+    end
+
+    it "adds library to allowed_missing_libraries on macOS when simulating Linux", :needs_macos do
+      Homebrew::SimulateSystem.os = :linux
+      f = formula do
+        url "foo-1.0"
+
+        ignore_missing_libraries "bar.so"
+      end
+      expect(f.class.allowed_missing_libraries.to_a).to eq(["bar.so"])
+    end
+
+    it "raises an error on macOS", :needs_macos do
+      Homebrew::SimulateSystem.clear
+      expect {
+        formula do
+          url "foo-1.0"
+
+          ignore_missing_libraries "bar.so"
+        end
+      }.to raise_error("ignore_missing_libraries is available on Linux only")
+    end
+
+    it "raises an error on Linux when simulating macOS", :needs_linux do
+      Homebrew::SimulateSystem.os = :macos
+      expect {
+        formula do
+          url "foo-1.0"
+
+          ignore_missing_libraries "bar.so"
+        end
+      }.to raise_error("ignore_missing_libraries is available on Linux only")
+    end
+  end
 end