8 files changed, 187 insertions, 214 deletions
diff --git a/lib/prism.rb b/lib/prism.rb
index 2bb7f79bf6..66a64e7fd0 100644
--- a/lib/prism.rb
+++ b/lib/prism.rb
@@ -13,7 +13,6 @@ module Prism
 
   autoload :BasicVisitor, "prism/visitor"
   autoload :Compiler, "prism/compiler"
-  autoload :Debug, "prism/debug"
   autoload :DesugarCompiler, "prism/desugar_compiler"
   autoload :Dispatcher, "prism/dispatcher"
   autoload :DotVisitor, "prism/dot_visitor"
@@ -32,7 +31,6 @@ module Prism
   # Some of these constants are not meant to be exposed, so marking them as
   # private here.
 
-  private_constant :Debug
   private_constant :LexCompat
   private_constant :LexRipper
 
diff --git a/lib/prism/debug.rb b/lib/prism/debug.rb
deleted file mode 100644
index 6380e628be..0000000000
--- a/lib/prism/debug.rb
+++ /dev/null
@@ -1,206 +0,0 @@
-# frozen_string_literal: true
-
-module Prism
-  # This module is used for testing and debugging and is not meant to be used by
-  # consumers of this library.
-  module Debug
-    # A wrapper around a RubyVM::InstructionSequence that provides a more
-    # convenient interface for accessing parts of the iseq.
-    class ISeq # :nodoc:
-      attr_reader :parts
-
-      def initialize(parts)
-        @parts = parts
-      end
-
-      def type
-        parts[0]
-      end
-
-      def local_table
-        parts[10]
-      end
-
-      def instructions
-        parts[13]
-      end
-
-      def each_child
-        instructions.each do |instruction|
-          # Only look at arrays. Other instructions are line numbers or
-          # tracepoint events.
-          next unless instruction.is_a?(Array)
-
-          instruction.each do |opnd|
-            # Only look at arrays. Other operands are literals.
-            next unless opnd.is_a?(Array)
-
-            # Only look at instruction sequences. Other operands are literals.
-            next unless opnd[0] == "YARVInstructionSequence/SimpleDataFormat"
-
-            yield ISeq.new(opnd)
-          end
-        end
-      end
-    end
-
-    private_constant :ISeq
-
-    # :call-seq:
-    #   Debug::cruby_locals(source) -> Array
-    #
-    # For the given source, compiles with CRuby and returns a list of all of the
-    # sets of local variables that were encountered.
-    def self.cruby_locals(source)
-      verbose, $VERBOSE = $VERBOSE, nil
-
-      begin
-        locals = [] #: Array[Array[Symbol | Integer]]
-        stack = [ISeq.new(RubyVM::InstructionSequence.compile(source).to_a)]
-
-        while (iseq = stack.pop)
-          names = [*iseq.local_table]
-          names.map!.with_index do |name, index|
-            # When an anonymous local variable is present in the iseq's local
-            # table, it is represented as the stack offset from the top.
-            # However, when these are dumped to binary and read back in, they
-            # are replaced with the symbol :#arg_rest. To consistently handle
-            # this, we replace them here with their index.
-            if name == :"#arg_rest"
-              names.length - index + 1
-            else
-              name
-            end
-          end
-
-          locals << names
-          iseq.each_child { |child| stack << child }
-        end
-
-        locals
-      ensure
-        $VERBOSE = verbose
-      end
-    end
-
-    # Used to hold the place of a local that will be in the local table but
-    # cannot be accessed directly from the source code. For example, the
-    # iteration variable in a for loop or the positional parameter on a method
-    # definition that is destructured.
-    AnonymousLocal = Object.new
-    private_constant :AnonymousLocal
-
-    # :call-seq:
-    #   Debug::prism_locals(source) -> Array
-    #
-    # For the given source, parses with prism and returns a list of all of the
-    # sets of local variables that were encountered.
-    def self.prism_locals(source)
-      locals = [] #: Array[Array[Symbol | Integer]]
-      stack = [Prism.parse(source).value] #: Array[Prism::node]
-
-      while (node = stack.pop)
-        case node
-        when BlockNode, DefNode, LambdaNode
-          names = node.locals
-          params =
-            if node.is_a?(DefNode)
-              node.parameters
-            elsif node.parameters.is_a?(NumberedParametersNode)
-              nil
-            else
-              node.parameters&.parameters
-            end
-
-          # prism places parameters in the same order that they appear in the
-          # source. CRuby places them in the order that they need to appear
-          # according to their own internal calling convention. We mimic that
-          # order here so that we can compare properly.
-          if params
-            sorted = [
-              *params.requireds.map do |required|
-                if required.is_a?(RequiredParameterNode)
-                  required.name
-                else
-                  AnonymousLocal
-                end
-              end,
-              *params.optionals.map(&:name),
-              *((params.rest.name || :*) if params.rest && !params.rest.is_a?(ImplicitRestNode)),
-              *params.posts.map do |post|
-                if post.is_a?(RequiredParameterNode)
-                  post.name
-                else
-                  AnonymousLocal
-                end
-              end,
-              *params.keywords.grep(RequiredKeywordParameterNode).map(&:name),
-              *params.keywords.grep(OptionalKeywordParameterNode).map(&:name),
-            ]
-
-            sorted << AnonymousLocal if params.keywords.any?
-
-            if params.keyword_rest.is_a?(ForwardingParameterNode)
-              sorted.push(:*, :**, :&, :"...")
-            elsif params.keyword_rest.is_a?(KeywordRestParameterNode)
-              sorted << (params.keyword_rest.name || :**)
-            end
-
-            # Recurse down the parameter tree to find any destructured
-            # parameters and add them after the other parameters.
-            param_stack = params.requireds.concat(params.posts).grep(MultiTargetNode).reverse
-            while (param = param_stack.pop)
-              case param
-              when MultiTargetNode
-                param_stack.concat(param.rights.reverse)
-                param_stack << param.rest if param.rest&.expression && !sorted.include?(param.rest.expression.name)
-                param_stack.concat(param.lefts.reverse)
-              when RequiredParameterNode
-                sorted << param.name
-              when SplatNode
-                sorted << param.expression.name
-              end
-            end
-
-            if params.block
-              sorted << (params.block.name || :&)
-            end
-
-            names = sorted.concat(names - sorted)
-          end
-
-          names.map!.with_index do |name, index|
-            if name == AnonymousLocal
-              names.length - index + 1
-            else
-              name
-            end
-          end
-
-          locals << names
-        when ClassNode, ModuleNode, ProgramNode, SingletonClassNode
-          locals << node.locals
-        when ForNode
-          locals << [2]
-        when PostExecutionNode
-          locals.push([], [])
-        when InterpolatedRegularExpressionNode
-          locals << [] if node.once?
-        end
-
-        stack.concat(node.compact_child_nodes)
-      end
-
-      locals
-    end
-
-    # :call-seq:
-    #   Debug::newlines(source) -> Array
-    #
-    # For the given source string, return the byte offsets of every newline in
-    # the source.
-    def self.newlines(source)
-      Prism.parse(source).source.offsets
-    end
-  end
-end
diff --git a/lib/prism/ffi.rb b/lib/prism/ffi.rb
index b62a59d037..df7e183310 100644
--- a/lib/prism/ffi.rb
+++ b/lib/prism/ffi.rb
@@ -394,7 +394,7 @@ module Prism
 
       template << "L"
       if (encoding = options[:encoding])
-        name = encoding.name
+        name = encoding.is_a?(Encoding) ? encoding.name : encoding
         values.push(name.bytesize, name.b)
         template << "A*"
       else
diff --git a/lib/prism/prism.gemspec b/lib/prism/prism.gemspec
index 374591bb70..b4504dbf4b 100644
--- a/lib/prism/prism.gemspec
+++ b/lib/prism/prism.gemspec
@@ -70,7 +70,6 @@ Gem::Specification.new do |spec|
     "include/prism/version.h",
     "lib/prism.rb",
     "lib/prism/compiler.rb",
-    "lib/prism/debug.rb",
     "lib/prism/desugar_compiler.rb",
     "lib/prism/dispatcher.rb",
     "lib/prism/dot_visitor.rb",
diff --git a/test/prism/comments_test.rb b/test/prism/comments_test.rb
index b99c00268c..952d03239c 100644
--- a/test/prism/comments_test.rb
+++ b/test/prism/comments_test.rb
@@ -6,7 +6,7 @@ module Prism
   class CommentsTest < TestCase
     def test_comment_inline
       source = "# comment"
-      assert_equal [0], Debug.newlines(source)
+      assert_equal [0], Prism.parse(source).source.offsets
 
       assert_comment(
         source,
diff --git a/test/prism/locals_test.rb b/test/prism/locals_test.rb
index 0eb73f1b9c..0e57a9a80c 100644
--- a/test/prism/locals_test.rb
+++ b/test/prism/locals_test.rb
@@ -41,8 +41,8 @@ module Prism
     def assert_locals(filepath)
       source = File.read(filepath)
 
-      expected = Debug.cruby_locals(source)
-      actual = Debug.prism_locals(source)
+      expected = cruby_locals(source)
+      actual = prism_locals(source)
 
       assert_equal(expected, actual)
     end
@@ -54,5 +54,186 @@ module Prism
     ensure
       $VERBOSE = previous_verbosity
     end
+
+    # A wrapper around a RubyVM::InstructionSequence that provides a more
+    # convenient interface for accessing parts of the iseq.
+    class ISeq
+      attr_reader :parts
+
+      def initialize(parts)
+        @parts = parts
+      end
+
+      def type
+        parts[0]
+      end
+
+      def local_table
+        parts[10]
+      end
+
+      def instructions
+        parts[13]
+      end
+
+      def each_child
+        instructions.each do |instruction|
+          # Only look at arrays. Other instructions are line numbers or
+          # tracepoint events.
+          next unless instruction.is_a?(Array)
+
+          instruction.each do |opnd|
+            # Only look at arrays. Other operands are literals.
+            next unless opnd.is_a?(Array)
+
+            # Only look at instruction sequences. Other operands are literals.
+            next unless opnd[0] == "YARVInstructionSequence/SimpleDataFormat"
+
+            yield ISeq.new(opnd)
+          end
+        end
+      end
+    end
+
+    # Used to hold the place of a local that will be in the local table but
+    # cannot be accessed directly from the source code. For example, the
+    # iteration variable in a for loop or the positional parameter on a method
+    # definition that is destructured.
+    AnonymousLocal = Object.new
+
+    # For the given source, compiles with CRuby and returns a list of all of the
+    # sets of local variables that were encountered.
+    def cruby_locals(source)
+      verbose, $VERBOSE = $VERBOSE, nil
+
+      begin
+        locals = [] #: Array[Array[Symbol | Integer]]
+        stack = [ISeq.new(RubyVM::InstructionSequence.compile(source).to_a)]
+
+        while (iseq = stack.pop)
+          names = [*iseq.local_table]
+          names.map!.with_index do |name, index|
+            # When an anonymous local variable is present in the iseq's local
+            # table, it is represented as the stack offset from the top.
+            # However, when these are dumped to binary and read back in, they
+            # are replaced with the symbol :#arg_rest. To consistently handle
+            # this, we replace them here with their index.
+            if name == :"#arg_rest"
+              names.length - index + 1
+            else
+              name
+            end
+          end
+
+          locals << names
+          iseq.each_child { |child| stack << child }
+        end
+
+        locals
+      ensure
+        $VERBOSE = verbose
+      end
+    end
+
+    # For the given source, parses with prism and returns a list of all of the
+    # sets of local variables that were encountered.
+    def prism_locals(source)
+      locals = [] #: Array[Array[Symbol | Integer]]
+      stack = [Prism.parse(source).value] #: Array[Prism::node]
+
+      while (node = stack.pop)
+        case node
+        when BlockNode, DefNode, LambdaNode
+          names = node.locals
+          params =
+            if node.is_a?(DefNode)
+              node.parameters
+            elsif node.parameters.is_a?(NumberedParametersNode)
+              nil
+            else
+              node.parameters&.parameters
+            end
+
+          # prism places parameters in the same order that they appear in the
+          # source. CRuby places them in the order that they need to appear
+          # according to their own internal calling convention. We mimic that
+          # order here so that we can compare properly.
+          if params
+            sorted = [
+              *params.requireds.map do |required|
+                if required.is_a?(RequiredParameterNode)
+                  required.name
+                else
+                  AnonymousLocal
+                end
+              end,
+              *params.optionals.map(&:name),
+              *((params.rest.name || :*) if params.rest && !params.rest.is_a?(ImplicitRestNode)),
+              *params.posts.map do |post|
+                if post.is_a?(RequiredParameterNode)
+                  post.name
+                else
+                  AnonymousLocal
+                end
+              end,
+              *params.keywords.grep(RequiredKeywordParameterNode).map(&:name),
+              *params.keywords.grep(OptionalKeywordParameterNode).map(&:name),
+            ]
+
+            sorted << AnonymousLocal if params.keywords.any?
+
+            if params.keyword_rest.is_a?(ForwardingParameterNode)
+              sorted.push(:*, :**, :&, :"...")
+            elsif params.keyword_rest.is_a?(KeywordRestParameterNode)
+              sorted << (params.keyword_rest.name || :**)
+            end
+
+            # Recurse down the parameter tree to find any destructured
+            # parameters and add them after the other parameters.
+            param_stack = params.requireds.concat(params.posts).grep(MultiTargetNode).reverse
+            while (param = param_stack.pop)
+              case param
+              when MultiTargetNode
+                param_stack.concat(param.rights.reverse)
+                param_stack << param.rest if param.rest&.expression && !sorted.include?(param.rest.expression.name)
+                param_stack.concat(param.lefts.reverse)
+              when RequiredParameterNode
+                sorted << param.name
+              when SplatNode
+                sorted << param.expression.name
+              end
+            end
+
+            if params.block
+              sorted << (params.block.name || :&)
+            end
+
+            names = sorted.concat(names - sorted)
+          end
+
+          names.map!.with_index do |name, index|
+            if name == AnonymousLocal
+              names.length - index + 1
+            else
+              name
+            end
+          end
+
+          locals << names
+        when ClassNode, ModuleNode, ProgramNode, SingletonClassNode
+          locals << node.locals
+        when ForNode
+          locals << [2]
+        when PostExecutionNode
+          locals.push([], [])
+        when InterpolatedRegularExpressionNode
+          locals << [] if node.once?
+        end
+
+        stack.concat(node.compact_child_nodes)
+      end
+
+      locals
+    end
   end
 end
diff --git a/test/prism/newline_test.rb b/test/prism/newline_test.rb
index cc7f21aec7..75593d34bf 100644
--- a/test/prism/newline_test.rb
+++ b/test/prism/newline_test.rb
@@ -10,6 +10,7 @@ module Prism
     filepaths = Dir["*.rb", base: base] - %w[
       encoding_test.rb
       errors_test.rb
+      locals_test.rb
       parser_test.rb
       regexp_test.rb
       static_literals_test.rb
diff --git a/test/prism/parse_test.rb b/test/prism/parse_test.rb
index afb53e0668..5c66caebb9 100644
--- a/test/prism/parse_test.rb
+++ b/test/prism/parse_test.rb
@@ -265,7 +265,7 @@ module Prism
         # Next, assert that the newlines are in the expected places.
         expected_newlines = [0]
         source.b.scan("\n") { expected_newlines << $~.offset(0)[0] + 1 }
-        assert_equal expected_newlines, Debug.newlines(source)
+        assert_equal expected_newlines, Prism.parse(source).source.offsets
 
         if ripper_should_match
           # Finally, assert that we can lex the source and get the same tokens as