Better handle nested constant names

Author: kddnewton

lib/syntax_tree/index.rb

@@ -176,45 +176,79 @@ def location_for(iseq)
         Location.new(code_location[0], code_location[1])
       end
 
+      def find_constant_path(insns, index)
+        insn = insns[index]
+
+        if insn.is_a?(Array) && insn[0] == :opt_getconstant_path
+          # In this case we're on Ruby 3.2+ and we have an opt_getconstant_path
+          # instruction, so we already know all of the symbols in the nesting.
+          insn[1]
+        elsif insn.is_a?(Symbol) && insn.match?(/\Alabel_\d+/)
+          # Otherwise, if we have a label then this is very likely the
+          # destination of an opt_getinlinecache instruction, in which case
+          # we'll walk backwards to grab up all of the constants.
+          names = []
+
+          index -= 1
+          until insns[index][0] == :opt_getinlinecache
+            names.unshift(insns[index][1]) if insns[index][0] == :getconstant
+            index -= 1
+          end
+
+          names
+        end
+      end
+
       def index_iseq(iseq, file_comments)
         results = []
         queue = [[iseq, []]]
 
         while (current_iseq, current_nesting = queue.shift)
-          current_iseq[13].each_with_index do |insn, index|
+          insns = current_iseq[13]
+          insns.each_with_index do |insn, index|
             next unless insn.is_a?(Array)
 
             case insn[0]
             when :defineclass
               _, name, class_iseq, flags = insn
+              next_nesting = current_nesting.dup
+
+              if (nesting = find_constant_path(insns, index - 2))
+                # If there is a constant path in the class name, then we need to
+                # handle that by updating the nesting.
+                next_nesting << (nesting << name)
+              else
+                # Otherwise we'll add the class name to the nesting.
+                next_nesting << [name]
+              end
 
               if flags == VM_DEFINECLASS_TYPE_SINGLETON_CLASS
                 # At the moment, we don't support singletons that aren't
                 # defined on self. We could, but it would require more
                 # emulation.
-                if current_iseq[13][index - 2] != [:putself]
+                if insns[index - 2] != [:putself]
                   raise NotImplementedError,
                         "singleton class with non-self receiver"
                 end
               elsif flags & VM_DEFINECLASS_TYPE_MODULE > 0
                 location = location_for(class_iseq)
                 results << ModuleDefinition.new(
-                  current_nesting,
+                  next_nesting,
                   name,
                   location,
                   EntryComments.new(file_comments, location)
                 )
               else
                 location = location_for(class_iseq)
                 results << ClassDefinition.new(
-                  current_nesting,
+                  next_nesting,
                   name,
                   location,
                   EntryComments.new(file_comments, location)
                 )
               end
 
-              queue << [class_iseq, current_nesting + [name]]
+              queue << [class_iseq, next_nesting]
             when :definemethod
               location = location_for(insn[2])
               results << MethodDefinition.new(
@@ -259,24 +293,36 @@ def initialize
 
         visit_methods do
           def visit_class(node)
-            name = visit(node.constant).to_sym
+            names = visit(node.constant)
+            nesting << names
+
             location =
               Location.new(node.location.start_line, node.location.start_column)
 
             results << ClassDefinition.new(
               nesting.dup,
-              name,
+              names.last,
               location,
               comments_for(node)
             )
 
-            nesting << name
             super
             nesting.pop
           end
 
           def visit_const_ref(node)
-            node.constant.value
+            [node.constant.value.to_sym]
+          end
+
+          def visit_const_path_ref(node)
+            names =
+              if node.parent.is_a?(ConstPathRef)
+                visit(node.parent)
+              else
+                [visit(node.parent)]
+              end
+
+            names << node.constant.value.to_sym
           end
 
           def visit_def(node)
@@ -302,18 +348,19 @@ def visit_def(node)
           end
 
           def visit_module(node)
-            name = visit(node.constant).to_sym
+            names = visit(node.constant)
+            nesting << names
+
             location =
               Location.new(node.location.start_line, node.location.start_column)
 
             results << ModuleDefinition.new(
               nesting.dup,
-              name,
+              names.last,
               location,
               comments_for(node)
             )
 
-            nesting << name
             super
             nesting.pop
           end
@@ -327,6 +374,10 @@ def visit_statements(node)
             @statements = node
             super
           end
+
+          def visit_var_ref(node)
+            node.value.value.to_sym
+          end
         end
 
         private

test/index_test.rb

@@ -7,14 +7,14 @@ class IndexTest < Minitest::Test
     def test_module
       index_each("module Foo; end") do |entry|
         assert_equal :Foo, entry.name
-        assert_empty entry.nesting
+        assert_equal [[:Foo]], entry.nesting
       end
     end
 
     def test_module_nested
       index_each("module Foo; module Bar; end; end") do |entry|
         assert_equal :Bar, entry.name
-        assert_equal [:Foo], entry.nesting
+        assert_equal [[:Foo], [:Bar]], entry.nesting
       end
     end
 
@@ -28,14 +28,35 @@ def test_module_comments
     def test_class
       index_each("class Foo; end") do |entry|
         assert_equal :Foo, entry.name
-        assert_empty entry.nesting
+        assert_equal [[:Foo]], entry.nesting
+      end
+    end
+
+    def test_class_paths_2
+      index_each("class Foo::Bar; end") do |entry|
+        assert_equal :Bar, entry.name
+        assert_equal [[:Foo, :Bar]], entry.nesting
+      end
+    end
+
+    def test_class_paths_3
+      index_each("class Foo::Bar::Baz; end") do |entry|
+        assert_equal :Baz, entry.name
+        assert_equal [[:Foo, :Bar, :Baz]], entry.nesting
       end
     end
 
     def test_class_nested
       index_each("class Foo; class Bar; end; end") do |entry|
         assert_equal :Bar, entry.name
-        assert_equal [:Foo], entry.nesting
+        assert_equal [[:Foo], [:Bar]], entry.nesting
+      end
+    end
+
+    def test_class_paths_nested
+      index_each("class Foo; class Bar::Baz::Qux; end; end") do |entry|
+        assert_equal :Qux, entry.name
+        assert_equal [[:Foo], [:Bar, :Baz, :Qux]], entry.nesting
       end
     end
 
@@ -56,7 +77,7 @@ def test_method
     def test_method_nested
       index_each("class Foo; def foo; end; end") do |entry|
         assert_equal :foo, entry.name
-        assert_equal [:Foo], entry.nesting
+        assert_equal [[:Foo]], entry.nesting
       end
     end
 
@@ -77,7 +98,7 @@ def test_singleton_method
     def test_singleton_method_nested
       index_each("class Foo; def self.foo; end; end") do |entry|
         assert_equal :foo, entry.name
-        assert_equal [:Foo], entry.nesting
+        assert_equal [[:Foo]], entry.nesting
       end
     end