[core] GraphQL: Move document filters to separate _ property/type

packages/@sanity/core/src/actions/graphql/v2/filters/documentFilters.js

@@ -0,0 +1,21 @@
+function createDocumentFilters() {
+  return {
+    name: 'DocumentFilter',
+    kind: 'InputObject',
+    isConstraintFilter: true,
+    fields: [
+      {
+        fieldName: 'references',
+        type: 'ID',
+        description: 'All documents referencing the given document ID.'
+      },
+      {
+        fieldName: 'is_draft',
+        type: 'Boolean',
+        description: 'All documents that are drafts.'
+      }
+    ]
+  }
+}
+
+module.exports = createDocumentFilters

packages/@sanity/core/src/actions/graphql/v2/generateTypeFilters.js

@@ -5,6 +5,7 @@ const createIntegerFilters = require('./filters/integerFilters')
 const createBooleanFilters = require('./filters/booleanFilters')
 const createDatetimeFilters = require('./filters/datetimeFilters')
 const createDateFilters = require('./filters/dateFilters')
+const createDocumentFilters = require('./filters/documentFilters')
 
 const typeAliases = {
   Url: 'String',
@@ -19,7 +20,8 @@ const filterCreators = {
   Integer: createIntegerFilters,
   Boolean: createBooleanFilters,
   Datetime: createDatetimeFilters,
-  Date: createDateFilters
+  Date: createDateFilters,
+  Document: createDocumentFilters
 }
 
 function generateTypeFilters(types) {
@@ -81,14 +83,9 @@ function createFieldFilters(objectType) {
 function getDocumentFilters() {
   return [
     {
-      fieldName: 'references',
-      type: 'ID',
-      description: 'All documents referencing the given document ID.'
-    },
-    {
-      fieldName: 'is_draft',
-      type: 'Boolean',
-      description: 'All documents that are drafts.'
+      fieldName: '_',
+      type: 'DocumentFilter',
+      description: 'Apply filters on document level'
     }
   ]
 }