Add "Objects must define fields" schema validation

CHANGELOG.md

@@ -11,6 +11,7 @@
 - Bug Fix: [Add `__private__` field to EnumValueDefinition](https://github.com/absinthe-graphql/absinthe/pull/1148)
 - Bug Fix: [Fix bug in Schema.**absinthe_types**(:all) for Persistent Term](https://github.com/absinthe-graphql/absinthe/pull/1161)
 - Bug Fix: [Fix default enum value check for SDL schema's](https://github.com/absinthe-graphql/absinthe/pull/1188)
+- Bug Fix: [Add "Objects must define fields" schema validation](https://github.com/absinthe-graphql/absinthe/pull/1167)
 - Feature: [Add `import_directives` macro](https://github.com/absinthe-graphql/absinthe/pull/1158)
 - Feature: [Support type extensions on schema declarations](https://github.com/absinthe-graphql/absinthe/pull/1176)
 - Bug Fix: [Root objects are marked as referenced correctly](https://github.com/absinthe-graphql/absinthe/pull/1186)

lib/absinthe/blueprint/schema.ex

@@ -69,12 +69,14 @@ defmodule Absinthe.Blueprint.Schema do
     build_types(attrs, [bp], [])
   end
 
+  def struct_to_kind(%struct{}), do: struct_to_kind(struct)
   def struct_to_kind(Blueprint.Schema.DirectiveDefinition), do: "directive"
   def struct_to_kind(Blueprint.Schema.EnumTypeDefinition), do: "enum type"
   def struct_to_kind(Blueprint.Schema.EnumValueDefinition), do: "enum value"
   def struct_to_kind(Blueprint.Schema.FieldDefinition), do: "field"
   def struct_to_kind(Blueprint.Schema.InputObjectTypeDefinition), do: "input object"
   def struct_to_kind(Blueprint.Schema.InputValueDefinition), do: "argument"
+  def struct_to_kind(Blueprint.Schema.InterfaceTypeDefinition), do: "interface"
   def struct_to_kind(Blueprint.Schema.ObjectTypeDefinition), do: "object"
   def struct_to_kind(Blueprint.Schema.ScalarTypeDefinition), do: "scalar"
   def struct_to_kind(Blueprint.Schema.UnionTypeDefinition), do: "union"

lib/absinthe/phase/schema/validation/object_must_define_fields.ex

@@ -0,0 +1,61 @@
+defmodule Absinthe.Phase.Schema.Validation.ObjectMustDefineFields do
+  @moduledoc false
+
+  use Absinthe.Phase
+  alias Absinthe.Blueprint
+
+  def run(bp, _) do
+    bp = Blueprint.prewalk(bp, &handle_schemas/1)
+    {:ok, bp}
+  end
+
+  defp handle_schemas(%Blueprint.Schema.SchemaDefinition{} = schema) do
+    schema = Blueprint.prewalk(schema, &validate_objects/1)
+    {:halt, schema}
+  end
+
+  defp handle_schemas(obj) do
+    obj
+  end
+
+  defp validate_objects(%struct{} = node)
+       when struct in [
+              Blueprint.Schema.ObjectTypeDefinition,
+              Blueprint.Schema.InterfaceTypeDefinition,
+              Blueprint.Schema.InputObjectTypeDefinition
+            ] do
+    if defines_fields?(node) do
+      node
+    else
+      put_error(node, error(node))
+    end
+  end
+
+  defp validate_objects(node) do
+    node
+  end
+
+  defp defines_fields?(%{fields: []}) do
+    false
+  end
+
+  defp defines_fields?(object) do
+    !Enum.all?(object.fields, &introspection?(&1))
+  end
+
+  defp introspection?(%{name: "__" <> _}), do: true
+  defp introspection?(_), do: false
+
+  defp error(object) do
+    %Absinthe.Phase.Error{
+      message: explanation(object),
+      locations: [object.__reference__.location],
+      phase: __MODULE__
+    }
+  end
+
+  def explanation(object) do
+    kind = Absinthe.Blueprint.Schema.struct_to_kind(object)
+    "The #{kind} type `#{object.identifier}` must define one or more fields."
+  end
+end

lib/absinthe/pipeline.ex

@@ -176,6 +176,7 @@ defmodule Absinthe.Pipeline do
       Phase.Schema.Directives,
       Phase.Schema.Validation.DefaultEnumValuePresent,
       Phase.Schema.Validation.DirectivesMustBeValid,
+      Phase.Schema.Validation.ObjectMustDefineFields,
       Phase.Schema.Validation.InputOutputTypesCorrectlyPlaced,
       Phase.Schema.Validation.InterfacesMustResolveTypes,
       Phase.Schema.Validation.ObjectInterfacesMustBeValid,

test/absinthe/execution/subscription_test.exs

@@ -41,7 +41,7 @@ defmodule Absinthe.Execution.SubscriptionTest do
     use Absinthe.Schema
 
     query do
-      # Query type must exist
+      field :foo, :string
     end
 
     object :user do

test/absinthe/integration/execution/introspection/full_test.exs

@@ -16,6 +16,11 @@ defmodule Elixir.Absinthe.Integration.Execution.Introspection.FullTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
+    end
+
+    def middleware(middleware, %{identifier: :foo}, _) do
+      middleware
     end
 
     def middleware(_, _, _) do

test/absinthe/phase/schema/reformat_description_test.exs

@@ -5,7 +5,7 @@ defmodule Absinthe.Phase.Schema.ReformatDescriptionTest do
     use Absinthe.Schema
 
     query do
-      # Must exist
+      field :foo, :string
     end
 
     object :via_macro do

test/absinthe/pipeline_test.exs

@@ -7,7 +7,7 @@ defmodule Absinthe.PipelineTest do
     use Absinthe.Schema
 
     query do
-      # Query type must exist
+      field :foo, :string
     end
   end
 

test/absinthe/schema/notation/experimental/import_directives_test.exs

@@ -23,6 +23,7 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportDirectivesTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     import_directives Source
@@ -32,6 +33,7 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportDirectivesTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     import_directives Source, only: [:one, :two]
@@ -41,12 +43,12 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportDirectivesTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     import_directives Source, except: [:one, :two]
   end
 
-  @tag :skip
   describe "import_directives" do
     test "without options" do
       assert [{Source, []}] == imports(WithoutOptions)

test/absinthe/schema/notation/experimental/import_type_extensions_test.exs

@@ -23,6 +23,7 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportTypeExtensionsTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     object :one do
@@ -41,6 +42,7 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportTypeExtensionsTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     object :one do
@@ -50,6 +52,7 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportTypeExtensionsTest do
     end
 
     object :three do
+      field :foo, :string
     end
 
     import_type_extensions Source, only: [:one, :two]
@@ -59,12 +62,15 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportTypeExtensionsTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     object :one do
+      field :foo, :string
     end
 
     object :two do
+      field :foo, :string
     end
 
     object :three do
@@ -87,14 +93,14 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportTypeExtensionsTest do
 
       assert [%{identifier: :one}] = fields(UsingOnlyOption, :one)
       assert [%{identifier: :two}] = fields(UsingOnlyOption, :two)
-      assert [] = fields(UsingOnlyOption, :three)
+      assert [%{identifier: :foo}] = fields(UsingOnlyOption, :three)
     end
 
     test "with :except" do
       assert [{Source, except: [:one, :two]}] == imports(UsingExceptOption)
 
-      assert [] = fields(UsingExceptOption, :one)
-      assert [] = fields(UsingExceptOption, :two)
+      assert [%{identifier: :foo}] = fields(UsingExceptOption, :one)
+      assert [%{identifier: :foo}] = fields(UsingExceptOption, :two)
       assert [%{identifier: :three}] = fields(UsingExceptOption, :three)
     end
   end

test/absinthe/schema/notation/experimental/import_types_test.exs

@@ -7,19 +7,23 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportTypesTest do
     use Absinthe.Schema.Notation
 
     object :one do
+      field :foo, :string
     end
 
     object :two do
+      field :foo, :string
     end
 
     object :three do
+      field :foo, :string
     end
   end
 
   defmodule WithoutOptions do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     import_types Source
@@ -29,6 +33,7 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportTypesTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     import_types(Source, only: [:one, :two])
@@ -38,6 +43,7 @@ defmodule Absinthe.Schema.Notation.Experimental.ImportTypesTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     import_types(Source, except: [:one, :two])

test/absinthe/schema/notation/experimental/macro_extensions_test.exs

@@ -24,6 +24,7 @@ defmodule Absinthe.Schema.Notation.Experimental.MacroExtensionsTest do
     @prototype_schema WithFeatureDirective
 
     query do
+      field :foo, :string
     end
 
     extend schema do
@@ -181,6 +182,10 @@ defmodule Absinthe.Schema.Notation.Experimental.MacroExtensionsTest do
                name: "__typename",
                type: :string
              },
+             %{
+               name: "foo",
+               type: :string
+             },
              %{
                name: "value",
                type: :integer
@@ -291,6 +296,7 @@ defmodule Absinthe.Schema.Notation.Experimental.MacroExtensionsTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     import_type_extensions ImportedSchema

test/absinthe/schema/notation/experimental/sdl_extensions_test.exs

@@ -24,6 +24,7 @@ defmodule Absinthe.Schema.Notation.Experimental.SdlExtensionsTest do
     @prototype_schema WithFeatureDirective
 
     query do
+      field :foo, :string
     end
 
     import_sdl """
@@ -246,6 +247,7 @@ defmodule Absinthe.Schema.Notation.Experimental.SdlExtensionsTest do
     use Absinthe.Schema
 
     query do
+      field :foo, :string
     end
 
     import_type_extensions ImportedSchema

test/absinthe/schema/notation/import_test.exs

@@ -20,7 +20,7 @@ defmodule Absinthe.Schema.Notation.ImportTest do
         use Absinthe.Schema
 
         query do
-          # Query type must exist
+          field :foo, :string
         end
 
         object :foo do
@@ -41,7 +41,7 @@ defmodule Absinthe.Schema.Notation.ImportTest do
         use Absinthe.Schema
 
         query do
-          # Query type must exist
+          field :foo, :string
         end
 
         input_object :foo do
@@ -64,7 +64,7 @@ defmodule Absinthe.Schema.Notation.ImportTest do
         use Absinthe.Schema
 
         query do
-          # Query type must exist
+          field :foo, :string
         end
 
         object :cool_fields do
@@ -92,7 +92,7 @@ defmodule Absinthe.Schema.Notation.ImportTest do
         use Absinthe.Schema
 
         query do
-          # Query type must exist
+          field :foo, :string
         end
 
         object :foo do
@@ -211,7 +211,7 @@ defmodule Absinthe.Schema.Notation.ImportTest do
         use Absinthe.Schema
 
         query do
-          # Query type must exist
+          field :foo, :string
         end
 
         object :foo do
@@ -223,7 +223,7 @@ defmodule Absinthe.Schema.Notation.ImportTest do
         use Absinthe.Schema
 
         query do
-          # Query type must exist
+          field :foo, :string
         end
 
         object :bar do
@@ -235,7 +235,7 @@ defmodule Absinthe.Schema.Notation.ImportTest do
         use Absinthe.Schema
 
         query do
-          # Query type must exist
+          field :foo, :string
         end
 
         import_types Source1