1 files changed, 90 insertions, 0 deletions
diff --git a/test/irb/test_tracer.rb b/test/irb/test_tracer.rb
new file mode 100644
index 0000000000..540f8be131
--- /dev/null
+++ b/test/irb/test_tracer.rb
@@ -0,0 +1,90 @@
+# frozen_string_literal: false
+require 'tempfile'
+require 'irb'
+
+require_relative "helper"
+
+module TestIRB
+  class ContextWithTracerIntegrationTest < IntegrationTestCase
+    def setup
+      super
+
+      omit "Tracer gem is not available when running on TruffleRuby" if RUBY_ENGINE == "truffleruby"
+
+      @envs.merge!("NO_COLOR" => "true")
+    end
+
+    def example_ruby_file
+      <<~'RUBY'
+        class Foo
+          def self.foo
+            100
+          end
+        end
+
+        def bar(obj)
+          obj.foo
+        end
+
+        binding.irb
+      RUBY
+    end
+
+    def test_use_tracer_enabled_when_gem_is_unavailable
+      write_rc <<~RUBY
+        # Simulate the absence of the tracer gem
+        ::Kernel.send(:alias_method, :irb_original_require, :require)
+
+        ::Kernel.define_method(:require) do |name|
+          raise LoadError, "cannot load such file -- tracer (test)" if name.match?("tracer")
+          ::Kernel.send(:irb_original_require, name)
+        end
+
+        IRB.conf[:USE_TRACER] = true
+      RUBY
+
+      write_ruby example_ruby_file
+
+      output = run_ruby_file do
+        type "bar(Foo)"
+        type "exit"
+      end
+
+      assert_include(output, "Tracer extension of IRB is enabled but tracer gem wasn't found.")
+    end
+
+    def test_use_tracer_enabled_when_gem_is_available
+      write_rc <<~RUBY
+        IRB.conf[:USE_TRACER] = true
+      RUBY
+
+      write_ruby example_ruby_file
+
+      output = run_ruby_file do
+        type "bar(Foo)"
+        type "exit"
+      end
+
+      assert_include(output, "Object#bar at")
+      assert_include(output, "Foo.foo at")
+      assert_include(output, "Foo.foo #=> 100")
+      assert_include(output, "Object#bar #=> 100")
+
+      # Test that the tracer output does not include IRB's own files
+      assert_not_include(output, "irb/workspace.rb")
+    end
+
+    def test_use_tracer_is_disabled_by_default
+      write_ruby example_ruby_file
+
+      output = run_ruby_file do
+        type "bar(Foo)"
+        type "exit"
+      end
+
+      assert_not_include(output, "#depth:")
+      assert_not_include(output, "Foo.foo")
+    end
+
+  end
+end