KegOnlyReason: print only the explanation if there’s one

Closes Homebrew/homebrew#42073.

Signed-off-by: Baptiste Fontaine <batifon@yahoo.fr>

1 files changed, 13 insertions, 0 deletions

diff --git a/Library/Homebrew/test/test_formula_support.rb b/Library/Homebrew/test/test_formula_support.rb
new file mode 100644
index 000000000..08d10292f
--- /dev/null
+++ b/Library/Homebrew/test/test_formula_support.rb
@@ -0,0 +1,13 @@
+require "testing_env"
+
+class KegOnlyReasonTests < Homebrew::TestCase
+  def test_to_s_explanation
+    r = KegOnlyReason.new :provided_by_osx, "test"
+    assert_equal "test", r.to_s
+  end
+
+  def test_to_s_no_explanation
+    r = KegOnlyReason.new :provided_by_osx, ""
+    assert_match(/^OS X already provides/, r.to_s)
+  end
+end