RBS validation

Gemfile.lock

@@ -73,7 +73,7 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.11.1)
       ffi (~> 1.0)
-    rbs (3.6.0.pre.2)
+    rbs (3.6.0.pre.3)
       logger
     rdoc (6.7.0)
       psych (>= 4.0.0)

lib/steep.rb

@@ -75,6 +75,7 @@
 require "steep/subtyping/variable_variance"
 
 require "steep/diagnostic/helper"
+require "steep/diagnostic/result_printer2"
 require "steep/diagnostic/ruby"
 require "steep/diagnostic/signature"
 require "steep/diagnostic/lsp_formatter"

lib/steep/diagnostic/result_printer2.rb

@@ -0,0 +1,48 @@
+module Steep
+  module Diagnostic
+    module ResultPrinter2
+      def result_line(result)
+        case result
+        when Subtyping::Result::Failure
+          case result.error
+          when Subtyping::Result::Failure::UnknownPairError
+            nil
+          when Subtyping::Result::Failure::UnsatisfiedConstraints
+            "Unsatisfied constraints: #{result.relation}"
+          when Subtyping::Result::Failure::MethodMissingError
+            "Method `#{result.error.name}` is missing"
+          when Subtyping::Result::Failure::BlockMismatchError
+            "Incomaptible block: #{result.relation}"
+          when Subtyping::Result::Failure::ParameterMismatchError
+            if result.relation.params?
+              "Incompatible arity: #{result.relation.super_type} and #{result.relation.sub_type}"
+            else
+              "Incompatible arity: #{result.relation}"
+            end
+          when Subtyping::Result::Failure::PolyMethodSubtyping
+            "Unsupported polymorphic method comparison: #{result.relation}"
+          when Subtyping::Result::Failure::SelfBindingMismatch
+            "Incompatible block self type: #{result.relation}"
+          end
+        else
+          result.relation.to_s
+        end
+      end
+
+      def detail_lines
+        lines = StringIO.new.tap do |io|
+          failure_path = result.failure_path || []
+          failure_path.reverse_each.filter_map do |result|
+            result_line(result)
+          end.each.with_index(1) do |message, index|
+            io.puts "#{"  " * (index)}#{message}"
+          end
+        end.string.chomp
+
+        unless lines.empty?
+          lines
+        end
+      end
+    end
+  end
+end

lib/steep/diagnostic/ruby.rb

@@ -61,51 +61,6 @@ def detail_lines
         end
       end
 
-      module ResultPrinter2
-        def result_line(result)
-          case result
-          when Subtyping::Result::Failure
-            case result.error
-            when Subtyping::Result::Failure::UnknownPairError
-              nil
-            when Subtyping::Result::Failure::UnsatisfiedConstraints
-              "Unsatisfied constraints: #{result.relation}"
-            when Subtyping::Result::Failure::MethodMissingError
-              "Method `#{result.error.name}` is missing"
-            when Subtyping::Result::Failure::BlockMismatchError
-              "Incomaptible block: #{result.relation}"
-            when Subtyping::Result::Failure::ParameterMismatchError
-              if result.relation.params?
-                "Incompatible arity: #{result.relation.super_type} and #{result.relation.sub_type}"
-              else
-                "Incompatible arity: #{result.relation}"
-              end
-            when Subtyping::Result::Failure::PolyMethodSubtyping
-              "Unsupported polymorphic method comparison: #{result.relation}"
-            when Subtyping::Result::Failure::SelfBindingMismatch
-              "Incompatible block self type: #{result.relation}"
-            end
-          else
-            result.relation.to_s
-          end
-        end
-
-        def detail_lines
-          lines = StringIO.new.tap do |io|
-            failure_path = result.failure_path || []
-            failure_path.reverse_each.filter_map do |result|
-              result_line(result)
-            end.each.with_index(1) do |message, index|
-              io.puts "#{"  " * (index)}#{message}"
-            end
-          end.string.chomp
-
-          unless lines.empty?
-            lines
-          end
-        end
-      end
-
       class IncompatibleAssignment < Base
         attr_reader :lhs_type
         attr_reader :rhs_type

lib/steep/diagnostic/signature.rb

@@ -105,12 +105,16 @@ class UnsatisfiableTypeApplication < Base
         attr_reader :type_name
         attr_reader :type_arg
         attr_reader :type_param
+        attr_reader :result
 
-        def initialize(type_name:, type_arg:, type_param:, location:)
+        include ResultPrinter2
+
+        def initialize(type_name:, type_arg:, type_param:, result:, location:)
           super(location: location)
           @type_name = type_name
           @type_arg = type_arg
           @type_param = type_param
+          @result = result
         end
 
         def header_line
@@ -248,14 +252,20 @@ def header_line
       class ModuleSelfTypeError < Base
         attr_reader :name
         attr_reader :ancestor
-        attr_reader :relation
+        attr_reader :result
+
+        include ResultPrinter2
 
-        def initialize(name:, ancestor:, relation:, location:)
+        def initialize(name:, ancestor:, result:, location:)
           super(location: location)
 
           @name = name
           @ancestor = ancestor
-          @relation = relation
+          @result = result
+        end
+
+        def relation
+          result.relation
         end
 
         def header_line
@@ -417,6 +427,40 @@ def header_line
         end
       end
 
+      class TypeParamDefaultReferenceError < Base
+        attr_reader :type_param
+
+        def initialize(type_param, location:)
+          super(location: location)
+          @type_param = type_param
+        end
+
+        def header_line
+          "The default type of `#{type_param.name}` cannot depend on optional type parameters"
+        end
+      end
+
+      class UnsatisfiableGenericsDefaultType < Base
+        attr_reader :param_name, :result
+
+        include ResultPrinter2
+
+        def initialize(param_name, result, location:)
+          super(location: location)
+          @param_name = param_name
+          @result = result
+        end
+
+        def relation
+          result.relation
+        end
+
+        def header_line
+          "The default type of `#{param_name}` doesn't satisfy upper bound constarint: #{relation}"
+        end
+      end
+
+
       def self.from_rbs_error(error, factory:)
         case error
         when RBS::ParsingError
@@ -515,6 +559,8 @@ def self.from_rbs_error(error, factory:)
           Diagnostic::Signature::InconsistentClassModuleAliasError.new(decl: error.alias_entry.decl)
         when RBS::CyclicClassAliasDefinitionError
           Diagnostic::Signature::CyclicClassAliasDefinitionError.new(decl: error.alias_entry.decl)
+        when RBS::TypeParamDefaultReferenceError
+          Diagnostic::Signature::TypeParamDefaultReferenceError.new(error.type_param, location: error.location)
         else
           raise error
         end

lib/steep/signature/validator.rb

@@ -104,6 +104,7 @@ def validate_type_application_constraints(type_name, type_params, type_args, loc
                     unchecked: param.unchecked?,
                     default_type: factory.type_opt(param.default_type)
                   ),
+                  result: result,
                   location: location
                 )
               end
@@ -252,6 +253,39 @@ def validate_definition_type(definition)
         end
       end
 
+      def validate_type_params(type_name, type_params)
+        if error_type_params = RBS::AST::TypeParam.validate(type_params)
+          error_type_params.each do |type_param|
+            default_type = type_param.default_type or raise
+            @errors << Diagnostic::Signature::TypeParamDefaultReferenceError.new(type_param, location: default_type.location)
+          end
+        end
+
+        upper_bounds = type_params.each.with_object({}) do |param, bounds| #$ Hash[Symbol, AST::Types::t?]
+          bounds[param.name] = factory.type_opt(param.upper_bound_type)
+        end
+
+        checker.push_variable_bounds(upper_bounds) do
+          type_params.each do |type_param|
+            param = checker.factory.type_param(type_param)
+
+            default_type = param.default_type or next
+            upper_bound = param.upper_bound or next
+
+            relation = Subtyping::Relation.new(sub_type: default_type, super_type: upper_bound)
+            result = checker.check(relation, self_type: nil, instance_type: nil, class_type: nil, constraints: Subtyping::Constraints.empty)
+
+            if result.failure?
+              @errors << Diagnostic::Signature::UnsatisfiableGenericsDefaultType.new(
+                type_param.name,
+                result,
+                location: (type_param.default_type || raise).location
+              )
+            end
+          end
+        end
+      end
+
       def validate_one_class_decl(name, entry)
         rescue_validation_errors(name) do
           Steep.logger.debug { "Validating class definition `#{name}`..." }
@@ -310,7 +344,7 @@ def validate_one_class_decl(name, entry)
                         name: name,
                         location: ancestor.source&.location || raise,
                         ancestor: ancestor,
-                        relation: relation
+                        result: _1
                       )
                     end
                   end
@@ -405,7 +439,7 @@ def validate_one_class_decl(name, entry)
                       name: name,
                       location: ancestor.source&.location || raise,
                       ancestor: ancestor,
-                      relation: relation
+                      result: _1
                     )
                   end
                 end
@@ -419,6 +453,8 @@ def validate_one_class_decl(name, entry)
                 validate_definition_type(definition)
               end
             end
+
+            validate_type_params(name, entry.type_params)
           end
         end
       end
@@ -480,6 +516,8 @@ def validate_one_interface(name)
           Steep.logger.tagged "#{name}" do
             definition = builder.build_interface(name)
 
+            validate_type_params(name, definition.type_params_decl)
+
             upper_bounds = definition.type_params_decl.each.with_object({}) do |param, bounds|
               bounds[param.name] = factory.type_opt(param.upper_bound_type)
             end
@@ -575,6 +613,8 @@ def validate_one_alias(name, entry = env.type_alias_decls[name])
               builder.validate_type_name(outer, entry.decl.location&.aref(:name))
             end
 
+            validate_type_params(name, entry.decl.type_params)
+
             upper_bounds = entry.decl.type_params.each.with_object({}) do |param, bounds|
               bounds[param.name] = factory.type_opt(param.upper_bound_type)
             end

sample/sig/generics.rbs

@@ -0,0 +1,15 @@
+module LocationHelper : _WithLocation
+  interface _WithLocation
+    def location_method: () -> String
+  end
+
+  def hello: () -> void
+end
+
+class StringGeneric[X < Integer, Y < Integer = String]
+  def location_method: () -> Integer
+
+  include LocationHelper
+  extend LocationHelper
+end
+

sig/steep/diagnostic/result_printer2.rbs

@@ -0,0 +1,13 @@
+module Steep
+  module Diagnostic
+    module ResultPrinter2 : _DiagnosticWithResult
+      interface _DiagnosticWithResult
+        def result: () -> Subtyping::Result::t
+      end
+
+      def result_line: (Subtyping::Result::t result) -> String?
+
+      def detail_lines: () -> String?
+    end
+  end
+end

sig/steep/diagnostic/ruby.rbs

@@ -29,12 +29,6 @@ module Steep
         def detail_lines: () -> String?
       end
 
-      module ResultPrinter2 : _DiagnosticWithResult
-        def result_line: (Subtyping::Result::t result) -> String?
-
-        def detail_lines: () -> String?
-      end
-
       class IncompatibleAssignment < Base
         attr_reader lhs_type: untyped
 
@@ -648,7 +642,7 @@ module Steep
 
         attr_reader block_pair: [Interface::Block?, Interface::Block?]?
 
-        attr_reader result: Subtyping::Result::Base
+        attr_reader result: Subtyping::Result::t
 
         include ResultPrinter2