Add specs for

library/objectspace/trace_spec.rb

@@ -0,0 +1,22 @@
+require_relative '../../spec_helper'
+
+ruby_version_is "3.1" do
+  describe 'require "objspace/trace"' do
+    it "shows object allocation sites" do
+      code = <<-RUBY
+        require "objspace/trace"
+        a = "foo"
+        b = "b" + "a" + "r"
+        c = 42
+        p a, b, c
+      RUBY
+
+      lines = ruby_exe(code, args: "2>&1").lines(chomp: true)
+      lines.size.should == 4
+      lines[0].should == "objspace/trace is enabled"
+      lines[1].should =~ /\A"foo" @ .*:2\z/
+      lines[2].should =~ /\A"bar" @ .*:3\z/
+      lines[3].should == "42"
+    end
+  end
+end