Guard ruby/spec with spec/mspec/tool/wrap_with_guard.rb

Merged: https://github.com/ruby/ruby/pull/4530

spec/ruby/library/matrix/vector/normalize_spec.rb

@@ -1,18 +1,21 @@
 require_relative '../../../spec_helper'
-require 'matrix'
 
-describe "Vector#normalize" do
-  it "returns a normalized copy of the vector" do
-    x = 0.2672612419124244
-    Vector[1, 2, 3].normalize.should == Vector[x, x * 2, x * 3]
-  end
+ruby_version_is ""..."3.1" do
+  require 'matrix'
 
-  it "raises an error for zero vectors" do
-    -> {
-      Vector[].normalize
-    }.should raise_error(Vector::ZeroVectorError)
-    -> {
-      Vector[0, 0, 0].normalize
-    }.should raise_error(Vector::ZeroVectorError)
+  describe "Vector#normalize" do
+    it "returns a normalized copy of the vector" do
+      x = 0.2672612419124244
+      Vector[1, 2, 3].normalize.should == Vector[x, x * 2, x * 3]
+    end
+
+    it "raises an error for zero vectors" do
+      -> {
+        Vector[].normalize
+      }.should raise_error(Vector::ZeroVectorError)
+      -> {
+        Vector[0, 0, 0].normalize
+      }.should raise_error(Vector::ZeroVectorError)
+    end
   end
 end