1 files changed, 27 insertions, 0 deletions
diff --git a/test/mkmf/test_egrep_cpp.rb b/test/mkmf/test_egrep_cpp.rb
new file mode 100644
index 0000000000..1126324965
--- /dev/null
+++ b/test/mkmf/test_egrep_cpp.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: false
+require_relative 'base'
+require 'tempfile'
+
+class TestMkmfEgrepCpp < TestMkmf
+  def test_egrep_cpp
+    assert_equal(true, egrep_cpp(/ruby_init/, ""), MKMFLOG)
+  end
+
+  def test_not_have_func
+    assert_equal(false, egrep_cpp(/never match/, ""), MKMFLOG)
+  end
+
+  class TestMkmfEgrepCxx < self
+    def test_cxx_egrep_cpp
+      assert_equal(true, MakeMakefile["C++"].egrep_cpp(/^ok/, <<~SRC), MKMFLOG)
+      #ifdef __cplusplus
+      ok
+      #else
+      #error not C++
+      #endif
+      SRC
+    rescue Errno::ENOENT
+      omit "C++ compiler not available: #{$!.message}"
+    end
+  end
+end