[PRISM] Frozen string literals should be fstrings

Frozen string literals should not just be frozen, but deduplicated as an
fstring so that two string literals with the same contents are the exact
same object.

Fixes ruby/prism#2095.

1 files changed, 17 insertions, 8 deletions

diff --git a/test/ruby/test_compile_prism.rb b/test/ruby/test_compile_prism.rb
index 5482a1529d..b02c1d09a3 100644
--- a/test/ruby/test_compile_prism.rb
+++ b/test/ruby/test_compile_prism.rb
@@ -638,14 +638,23 @@ module Prism
       assert_prism_eval('"pit"')
       assert_prism_eval('"a".frozen?')
 
-      frozen_source = <<-CODE
-      # frozen_string_literal: true
-      "a".frozen?
-      CODE
-      ruby_eval = RubyVM::InstructionSequence.compile(frozen_source).eval
-      prism_eval = RubyVM::InstructionSequence.compile_prism(frozen_source).eval
-
-      assert_equal ruby_eval, prism_eval
+      [
+        # Test that string literal is frozen
+        <<~RUBY,
+          # frozen_string_literal: true
+          "a".frozen?
+        RUBY
+        # Test that two string literals with the same contents are the same string
+        <<~RUBY,
+          # frozen_string_literal: true
+          "hello".equal?("hello")
+        RUBY
+      ].each do |src|
+        ruby_eval = RubyVM::InstructionSequence.compile(src).eval
+        prism_eval = RubyVM::InstructionSequence.compile_prism(src).eval
+
+        assert_equal ruby_eval, prism_eval, src
+      end
     end
 
     def test_SymbolNode