1 files changed, 94 insertions, 0 deletions
diff --git a/spec/ruby/command_line/frozen_strings_spec.rb b/spec/ruby/command_line/frozen_strings_spec.rb
new file mode 100644
index 0000000000..8acab5bc1d
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+++ b/spec/ruby/command_line/frozen_strings_spec.rb
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+require_relative '../spec_helper'
+
+describe "The --enable-frozen-string-literal flag causes string literals to" do
+
+  it "produce the same object each time" do
+    ruby_exe(fixture(__FILE__, "freeze_flag_one_literal.rb"), options: "--enable-frozen-string-literal").chomp.should == "true"
+  end
+
+  it "produce the same object for literals with the same content" do
+    ruby_exe(fixture(__FILE__, "freeze_flag_two_literals.rb"), options: "--enable-frozen-string-literal").chomp.should == "true"
+  end
+
+  it "produce the same object for literals with the same content in different files" do
+    ruby_exe(fixture(__FILE__, "freeze_flag_across_files.rb"), options: "--enable-frozen-string-literal").chomp.should == "true"
+  end
+
+  it "produce different objects for literals with the same content in different files if they have different encodings" do
+    ruby_exe(fixture(__FILE__, "freeze_flag_across_files_diff_enc.rb"), options: "--enable-frozen-string-literal").chomp.should == "true"
+  end
+end
+
+describe "The --disable-frozen-string-literal flag causes string literals to" do
+
+  it "produce a different object each time" do
+    ruby_exe(fixture(__FILE__, "freeze_flag_one_literal.rb"), options: "--disable-frozen-string-literal").chomp.should == "false"
+  end
+
+end
+
+describe "With neither --enable-frozen-string-literal nor --disable-frozen-string-literal flag set" do
+  before do
+    # disable --enable-frozen-string-literal and --disable-frozen-string-literal passed in $RUBYOPT
+    @rubyopt = ENV["RUBYOPT"]
+    ENV["RUBYOPT"] = ""
+  end
+
+  after do
+    ENV["RUBYOPT"] = @rubyopt
+  end
+
+  it "produce a different object each time" do
+    ruby_exe(fixture(__FILE__, "freeze_flag_one_literal.rb")).chomp.should == "false"
+  end
+
+  context "if file has no frozen_string_literal comment" do
+    it "produce different mutable strings each time" do
+      ruby_exe(fixture(__FILE__, "string_literal_raw.rb")).chomp.should == "frozen:false interned:false"
+    end
+
+    guard -> { ruby_version_is "3.4" and !"test".frozen? } do
+      it "complain about modification of produced mutable strings" do
+        -> { eval(<<~RUBY) }.should complain(/warning: literal string will be frozen in the future \(run with --debug-frozen-string-literal for more information\)/)
+          "test" << "!"
+        RUBY
+      end
+
+      it "does not complain about modification if Warning[:deprecated] is false" do
+        deprecated = Warning[:deprecated]
+        Warning[:deprecated] = false
+        -> { eval(<<~RUBY) }.should_not complain
+          "test" << "!"
+        RUBY
+      ensure
+        Warning[:deprecated] = deprecated
+      end
+    end
+  end
+
+  it "if file has frozen_string_literal:true comment produce same frozen strings each time" do
+    ruby_exe(fixture(__FILE__, "string_literal_frozen_comment.rb")).chomp.should == "frozen:true interned:true"
+  end
+
+  it "if file has frozen_string_literal:false comment produce different mutable strings each time" do
+    ruby_exe(fixture(__FILE__, "string_literal_mutable_comment.rb")).chomp.should == "frozen:false interned:false"
+  end
+end
+
+describe "The --debug flag produces" do
+  it "debugging info on attempted frozen string modification" do
+    error_str = ruby_exe(fixture(__FILE__, 'debug_info.rb'), options: '--enable-frozen-string-literal --debug',  args: "2>&1")
+    error_str.should include("can't modify frozen String")
+    error_str.should include("created at")
+    error_str.should include("command_line/fixtures/debug_info.rb:1")
+  end
+
+  guard -> { ruby_version_is "3.4" and !"test".frozen? } do
+    it "debugging info on mutating chilled string" do
+      error_str = ruby_exe(fixture(__FILE__, 'debug_info.rb'), options: '-w --debug',  args: "2>&1")
+      error_str.should include("literal string will be frozen in the future")
+      error_str.should include("the string was created here")
+      error_str.should include("command_line/fixtures/debug_info.rb:1")
+    end
+  end
+end