Convert `formula_support` test to spec.

Library/Homebrew/test/formula_support_spec.rb

+require "formula_support"
+
+describe KegOnlyReason do
+  describe "#to_s" do
+    it "returns the reason provided" do
+      r = KegOnlyReason.new :provided_by_osx, "test"
+      expect(r.to_s).to eq("test")
+    end
+
+    it "returns a default message when no reason is provided" do
+      r = KegOnlyReason.new :provided_by_macos, ""
+      expect(r.to_s).to match(/^macOS already provides/)
+    end
+  end
+end
+
+describe BottleDisableReason do
+  specify ":unneeded" do
+    bottle_disable_reason = BottleDisableReason.new :unneeded, nil
+    expect(bottle_disable_reason).to be_unneeded
+    expect(bottle_disable_reason.to_s).to eq("This formula doesn't require compiling.")
+  end
+
+  specify ":disabled" do
+    bottle_disable_reason = BottleDisableReason.new :disable, "reason"
+    expect(bottle_disable_reason).not_to be_unneeded
+    expect(bottle_disable_reason.to_s).to eq("reason")
+  end
+end

Library/Homebrew/test/formula_support_test.rb

-require "testing_env"
-require "formula_support"
-
-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_macos, ""
-    assert_match(/^macOS already provides/, r.to_s)
-  end
-end
-
-class BottleDisableReasonTests < Homebrew::TestCase
-  def test_bottle_unneeded
-    bottle_disable_reason = BottleDisableReason.new :unneeded, nil
-    assert_predicate bottle_disable_reason, :unneeded?
-    assert_equal "This formula doesn't require compiling.", bottle_disable_reason.to_s
-  end
-
-  def test_bottle_disabled
-    bottle_disable_reason = BottleDisableReason.new :disable, "reason"
-    refute_predicate bottle_disable_reason, :unneeded?
-    assert_equal "reason", bottle_disable_reason.to_s
-  end
-end