feat: add support for Map type (added in Mongoose 5.1.0)

closes #186

Author: nodkz

src/__mocks__/userModel.js

@@ -94,6 +94,18 @@ const UserSchema: SchemaType<any> = new Schema(
       type: Schema.Types.Decimal128,
     },
 
+    mapField: {
+      type: Map,
+      of: String,
+    },
+
+    mapFieldDeep: {
+      subField: {
+        type: Map,
+        of: String,
+      },
+    },
+
     // createdAt, created via option `timastamp: true` (see bottom)
     // updatedAt, created via option `timastamp: true` (see bottom)
   },

src/__tests__/fieldConverter-test.js

@@ -310,5 +310,11 @@ describe('fieldConverter', () => {
     it('should work with Decimal128', () => {
       expect(tc.getFieldTypeName('salary')).toBe('BSONDecimal');
     });
+
+    it('should work with Map', () => {
+      expect(tc.getFieldTypeName('mapField')).toBe('JSON');
+      expect(tc.getFieldTypeName('mapFieldDeep')).toBe('UserMapFieldDeep');
+      expect(tc.getFieldOTC('mapFieldDeep').getFieldTypeName('subField')).toBe('JSON');
+    });
   });
 });

src/fieldsConverter.js

@@ -69,6 +69,9 @@ export function dotPathsToEmbedded(fields: MongooseFieldMapT): MongooseFieldMapT
     const dotIdx = fieldName.indexOf('.');
     if (dotIdx === -1) {
       result[fieldName] = fields[fieldName];
+    } else if (fieldName.substr(dotIdx, 3) === '.$*') {
+      // skip { type: Map of: String }
+      // do not add this field to result
     } else {
       // create pseudo sub-model
       const name = fieldName.substr(0, dotIdx);