feat(FieldConverter): now support deeply nested arrays

Will be returned type `[SomeDeepFieldPeriods]` instead of `JSON` for field `someDeepField`:
```js
const UserSchema = new Schema({
  someDeepField: {
    periods: [{ from: Number, to: Number }],
  },
});
```

Author: nodkz

src/__mocks__/userModel.js

@@ -85,6 +85,10 @@ const UserSchema = new Schema(
 
     periods: [{ from: Number, to: Number }],
 
+    someDeep: {
+      periods: [{ from: Number, to: Number }],
+    },
+
     // createdAt, created via option `timastamp: true` (see bottom)
     // updatedAt, created via option `timastamp: true` (see bottom)
   },

src/__tests__/__snapshots__/integration-test.js.snap

@@ -2,6 +2,7 @@
 
 exports[`integration tests projection should request all fields to rawData field: projection from all fields 1`] = `
 Array [
+  "someDeep",
   "users",
   "skills",
   "employment",

src/__tests__/fieldConverter-test.js

@@ -195,6 +195,16 @@ describe('fieldConverter', () => {
       expect(embeddedFields.locationId).toBeTruthy();
       expect(embeddedFields._id).toBeTruthy();
     });
+
+    it('test object with field as array', () => {
+      const someDeepTC = embeddedToGraphQL(fields.someDeep, '', schemaComposer);
+      expect(someDeepTC.getTypeName()).toBe('SomeDeep');
+      const periodsType = (someDeepTC.getField('periods'): any).type;
+      expect(Array.isArray(periodsType)).toBeTruthy();
+      expect(periodsType[0].getTypeName()).toBe('SomeDeepPeriods');
+      expect(periodsType[0].hasField('from')).toBeTruthy();
+      expect(periodsType[0].hasField('to')).toBeTruthy();
+    });
   });
 
   describe('documentArrayToGraphQL()', () => {

src/fieldsConverter.js

@@ -226,8 +226,10 @@ export function deriveComplexType(field: MongooseFieldT): $Keys<typeof ComplexTy
   }
 
   const fieldType = _getFieldType(field);
-
-  if (field instanceof mongoose.Schema.Types.DocumentArray) {
+  if (
+    field instanceof mongoose.Schema.Types.DocumentArray ||
+    (fieldType === 'Array' && objectPath.has(field, 'schema.paths'))
+  ) {
     return ComplexTypes.DOCUMENT_ARRAY;
   } else if (field instanceof mongoose.Schema.Types.Embedded || fieldType === 'Embedded') {
     return ComplexTypes.EMBEDDED;
@@ -346,7 +348,10 @@ export function documentArrayToGraphQL(
   prefix?: string = '',
   schemaComposer: SchemaComposer<any>
 ): [TypeComposer] {
-  if (!(field instanceof mongoose.Schema.Types.DocumentArray)) {
+  if (
+    !(field instanceof mongoose.Schema.Types.DocumentArray) &&
+    !objectPath.has(field, 'schema.paths')
+  ) {
     throw new Error(
       'You provide incorrect mongoose field to `documentArrayToGraphQL()`. ' +
         'Correct field should be instance of `mongoose.Schema.Types.DocumentArray`'
@@ -355,7 +360,7 @@ export function documentArrayToGraphQL(
 
   const typeName = `${prefix}${upperFirst(_getFieldName(field))}`;
 
-  const tc = convertModelToGraphQL(field, typeName, schemaComposer);
+  const tc = convertModelToGraphQL((field: any), typeName, schemaComposer);
 
   return [tc];
 }