feat: make the include option of Model.create default to all provided associations

packages/core/src/model-internals.ts

@@ -2,7 +2,7 @@ import NodeUtil from 'node:util';
 import type { IndexOptions } from './dialects/abstract/query-interface.js';
 import type { WhereAttributeHash } from './dialects/abstract/where-sql-builder-types.js';
 import { EagerLoadingError } from './errors';
-import type { Attributes, Model, Transactionable } from './model';
+import type { Attributes, Model, ModelStatic, Transactionable } from './model';
 import type { ModelDefinition } from './model-definition.js';
 import type { Sequelize } from './sequelize';
 import { isModelStatic } from './utils/model-utils.js';
@@ -273,3 +273,17 @@ Either add a primary key to this model, or use one of the following alternatives
     );
   }
 }
+
+export function getDefaultCreateInclude(model: ModelStatic, values: Object) {
+  const associations = [];
+  const associationNames = Object.keys(model.associations);
+  if (values) {
+    for (const value of Object.keys(values)) {
+      if (associationNames.includes(value)) {
+        associations.push(value);
+      }
+    }
+  }
+
+  return associations;
+}

packages/core/src/model.js

@@ -13,6 +13,7 @@ import { BaseSqlExpression } from './expression-builders/base-sql-expression.js'
 import {
   _validateIncludedElements,
   combineIncludes,
+  getDefaultCreateInclude,
   getModelPkWhere,
   setTransactionFromCls,
   throwInvalidInclude,
@@ -1916,6 +1917,7 @@ ${associationOwner._getAssociationDebugList()}`);
    */
   static async create(values, options) {
     options = cloneDeep(options) ?? {};
+    options.include ??= getDefaultCreateInclude(this, values);
 
     return await this.build(values, {
       isNewRecord: true,

packages/core/test/integration/model/create.test.js

@@ -1593,6 +1593,37 @@ describe(Support.getTestDialectTeaser('Model'), () => {
         });
       });
     });
+    it('should create associated objects without include option', async function () {
+      const Player = this.customSequelize.define('player', {
+        name: {
+          type: DataTypes.STRING,
+        },
+        teamId: {
+          type: DataTypes.INTEGER,
+        },
+      });
+      const Team = this.customSequelize.define('team', {
+        id: {
+          type: DataTypes.INTEGER,
+          primaryKey: true,
+        },
+        name: {
+          type: DataTypes.STRING,
+        },
+      });
+      Player.team = Player.belongsTo(Team, {
+        as: 'team',
+        foreignKey: 'teamId',
+        targetKey: 'id',
+      });
+      await this.customSequelize.sync({ force: true });
+      const createdPlayer = await Player.create({
+        name: 'Player 1',
+        team: { id: 1, name: 'My new team' },
+      });
+      expect(createdPlayer.team instanceof Team).to.be.ok;
+      expect(createdPlayer.teamId).to.equal(1);
+    });
   });
 
   it('should return autoIncrement primary key (create)', async function () {