feat(types): add InferAttributes utility type

types/lib/associations/belongs-to-many.d.ts

@@ -1,6 +1,6 @@
 import {
   BulkCreateOptions,
-  CreateOptions,
+  CreateOptions, CreationAttributes,
   Filterable,
   FindAttributeOptions,
   FindOptions,
@@ -9,7 +9,7 @@ import {
   Model,
   ModelCtor,
   ModelType,
-  Transactionable
+  Transactionable,
 } from '../model';
 import { Association, AssociationScope, ForeignKeyOptions, ManyToManyOptions, MultiAssociationAccessors } from './base';
 
@@ -303,7 +303,7 @@ export interface BelongsToManyCreateAssociationMixinOptions extends CreateOption
  * @see Instance
  */
 export type BelongsToManyCreateAssociationMixin<TModel extends Model> = (
-  values?: TModel['_creationAttributes'],
+  values?: CreationAttributes<TModel>,
   options?: BelongsToManyCreateAssociationMixinOptions
 ) => Promise<TModel>;
 

types/lib/associations/belongs-to.d.ts

@@ -1,5 +1,5 @@
 import { DataType } from '../data-types';
-import { CreateOptions, FindOptions, Model, ModelCtor, SaveOptions } from '../model';
+import { CreateOptions, CreationAttributes, FindOptions, Model, ModelCtor, SaveOptions } from '../model';
 import { Association, AssociationOptions, SingleAssociationAccessors } from './base';
 
 // type ModelCtor<M extends Model> = InstanceType<typeof M>;
@@ -117,7 +117,7 @@ export interface BelongsToCreateAssociationMixinOptions
  * @see Instance
  */
 export type BelongsToCreateAssociationMixin<TModel extends Model> = (
-  values?: TModel['_creationAttributes'],
+  values?: CreationAttributes<TModel>,
   options?: BelongsToCreateAssociationMixinOptions
 ) => Promise<TModel>;
 

types/lib/associations/has-many.d.ts

@@ -1,14 +1,15 @@
 import { DataType } from '../data-types';
 import {
-  CreateOptions,
+  CreateOptions, CreationAttributes,
   Filterable,
   FindOptions,
   InstanceUpdateOptions,
   Model,
   ModelCtor,
-  Transactionable
+  Transactionable,
 } from '../model';
 import { Association, ManyToManyOptions, MultiAssociationAccessors } from './base';
+import { MakeUndefinedOptional } from '../utils';
 
 /**
  * Options provided when associating models with hasMany relationship
@@ -211,10 +212,10 @@ export interface HasManyCreateAssociationMixinOptions extends CreateOptions<any>
  */
 export type HasManyCreateAssociationMixin<
   TModel extends Model,
-  TForeignKey extends keyof TModel['_creationAttributes'] = never,
-  TScope extends keyof TModel['_creationAttributes'] = never
+  TForeignKey extends keyof CreationAttributes<TModel> = never,
+  TScope extends keyof CreationAttributes<TModel> = never
 > = (
-  values?: Omit<TModel['_creationAttributes'], TForeignKey | TScope>,
+  values?: Omit<CreationAttributes<TModel>, TForeignKey | TScope>,
   options?: HasManyCreateAssociationMixinOptions
 ) => Promise<TModel>;
 

types/lib/associations/has-one.d.ts

@@ -1,5 +1,5 @@
 import { DataType } from '../data-types';
-import { CreateOptions, FindOptions, Model, ModelCtor, SaveOptions } from '../model';
+import { CreateOptions, CreationAttributes, FindOptions, Model, ModelCtor, SaveOptions } from '../model';
 import { Association, AssociationOptions, SingleAssociationAccessors } from './base';
 
 /**
@@ -114,6 +114,6 @@ export interface HasOneCreateAssociationMixinOptions extends HasOneSetAssociatio
  * @see Instance
  */
 export type HasOneCreateAssociationMixin<TModel extends Model> = (
-  values?: TModel['_creationAttributes'],
+  values?: CreationAttributes<TModel>,
   options?: HasOneCreateAssociationMixinOptions
 ) => Promise<TModel>;

types/lib/hooks.d.ts

@@ -1,4 +1,4 @@
-import { ModelType } from '../index';
+import { Attributes, CreationAttributes, ModelType } from '../index';
 import { ValidationOptions } from './instance-validator';
 import Model, {
   BulkCreateOptions,
@@ -97,11 +97,17 @@ export class Hooks<
   /**
    * A similar dummy variable that doesn't exist on the real object. Do not
    * try to access this in real code.
+   *
+   * @deprecated This property will become a Symbol in v7 to prevent collisions.
+   * Use Attributes<Model> instead of this property to be forward-compatible.
    */
   _attributes: TModelAttributes;
   /**
    * A similar dummy variable that doesn't exist on the real object. Do not
    * try to access this in real code.
+   *
+   * @deprecated This property will become a Symbol in v7 to prevent collisions.
+   * Use CreationAttributes<Model> instead of this property to be forward-compatible.
    */
   _creationAttributes: TCreationAttributes;
 
@@ -113,28 +119,28 @@ export class Hooks<
    */
   public static addHook<
     H extends Hooks,
-    K extends keyof SequelizeHooks<H['_model'], H['_attributes'], H['_creationAttributes']>
+    K extends keyof SequelizeHooks<H['_model'], Attributes<H>, CreationAttributes<H>>
     >(
     this: HooksStatic<H>,
     hookType: K,
     name: string,
-    fn: SequelizeHooks<H['_model'], H['_attributes'], H['_creationAttributes']>[K]
+    fn: SequelizeHooks<H['_model'], Attributes<H>, CreationAttributes<H>>[K]
   ): HooksCtor<H>;
   public static addHook<
     H extends Hooks,
-    K extends keyof SequelizeHooks<H['_model'], H['_attributes'], H['_creationAttributes']>
+    K extends keyof SequelizeHooks<H['_model'], Attributes<H>, CreationAttributes<H>>
   >(
     this: HooksStatic<H>,
     hookType: K,
-    fn: SequelizeHooks<H['_model'], H['_attributes'], H['_creationAttributes']>[K]
+    fn: SequelizeHooks<H['_model'], Attributes<H>, CreationAttributes<H>>[K]
   ): HooksCtor<H>;
 
   /**
    * Remove hook from the model
    */
   public static removeHook<H extends Hooks>(
     this: HooksStatic<H>,
-    hookType: keyof SequelizeHooks<H['_model'], H['_attributes'], H['_creationAttributes']>,
+    hookType: keyof SequelizeHooks<H['_model'], Attributes<H>, CreationAttributes<H>>,
     name: string,
   ): HooksCtor<H>;
 
@@ -143,11 +149,11 @@ export class Hooks<
    */
   public static hasHook<H extends Hooks>(
     this: HooksStatic<H>,
-    hookType: keyof SequelizeHooks<H['_model'], H['_attributes'], H['_creationAttributes']>,
+    hookType: keyof SequelizeHooks<H['_model'], Attributes<H>, CreationAttributes<H>>,
   ): boolean;
   public static hasHooks<H extends Hooks>(
     this: HooksStatic<H>,
-    hookType: keyof SequelizeHooks<H['_model'], H['_attributes'], H['_creationAttributes']>,
+    hookType: keyof SequelizeHooks<H['_model'], Attributes<H>, CreationAttributes<H>>,
   ): boolean;
 
   /**