Add a spec for reading caller variables and bindings.

Author: aardvark179

spec/truffle/caller_data_spec.rb

@@ -0,0 +1,76 @@
+# truffleruby_primitives: true
+
+# Copyright (c) 2021 Oracle and/or its affiliates. All rights reserved. This
+# code is released under a tri EPL/GPL/LGPL license. You can use it,
+# redistribute it and/or modify it under the terms of the:
+#
+# Eclipse Public License version 2.0, or
+# GNU General Public License version 2, or
+# GNU Lesser General Public License version 2.1.
+
+require_relative '../ruby/spec_helper'
+
+module TruffleCallerSpecFixtures
+
+  def self.last_line_set(last_line)
+    Primitive.io_last_line_set(Primitive.caller_special_variables, last_line)
+    last_line
+  end
+
+  def self.last_match_set(match)
+    Primitive.regexp_last_match_set(Primitive.caller_special_variables, match)
+    match
+  end
+
+  def self.caller_binding
+    Primitive.caller_binding
+  end
+
+  def self.caller_binding_and_variables(last_line, last_match)
+    b = Primitive.caller_binding
+    Primitive.io_last_line_set(Primitive.caller_special_variables, last_line)
+    Primitive.regexp_last_match_set(Primitive.caller_special_variables, last_match)
+    b
+  end
+
+end
+
+describe "A caller" do
+
+  it "can have its special variables read and modified" do
+    last_line = "Hello!"
+    md = Primitive.matchdata_create(/o/, "Hello", [4], [5])
+    TruffleCallerSpecFixtures.last_line_set(last_line)
+    TruffleCallerSpecFixtures.last_match_set(md)
+    $_.should == last_line
+    $~.should == md
+  end
+
+  it "can have its special variables read and modified through an intermediate #send" do
+    last_line = "Hello!"
+    md = Primitive.matchdata_create(/o/, "Hello", [4], [5])
+    TruffleCallerSpecFixtures.send(:last_line_set, last_line)
+    TruffleCallerSpecFixtures.send(:last_match_set, md)
+    $_.should == last_line
+    $~.should == md
+  end
+
+  it "can have its special variables and frame read by the same method" do
+    last_line = "Hello!"
+    md = Primitive.matchdata_create(/o/, "Hello", [4], [5])
+    b = TruffleCallerSpecFixtures.caller_binding_and_variables(last_line, md)
+    $_.should == last_line
+    $~.should == md
+    b.local_variable_get(:md).should == md
+  end
+
+  it "can have its special variables and frame read by the same method through an intermediate #send" do
+    last_line = "Hello!"
+    md = Primitive.matchdata_create(/o/, "Hello", [4], [5])
+    b = TruffleCallerSpecFixtures.send(:caller_binding_and_variables, last_line, md)
+    $_.should == last_line
+    $~.should == md
+    b.local_variable_get(:md).should == md
+  end
+
+end