fix(types): adding upsert with returning: true (#10800)

types/lib/model.d.ts

@@ -1919,9 +1919,15 @@ export abstract class Model<T = any, T2 = any> extends Hooks {
   public static upsert<M extends Model>(
     this: { new (): M } & typeof Model,
     values: object,
-    options?: UpsertOptions
+    options?: UpsertOptions & { returning?: false | undefined }
   ): Promise<boolean>;
 
+  public static upsert<M extends Model> (
+    this: { new (): M } & typeof Model,
+    values: object,
+    options?: UpsertOptions & { returning: true }
+  ): Promise<[ M, boolean ]>;
+
   /**
    * Create and insert multiple instances in bulk.
    *

types/test/upsert.ts

@@ -7,7 +7,7 @@ class TestModel extends Model {
 TestModel.init({}, {sequelize})
 
 sequelize.transaction(trx => {
-  return TestModel.upsert({}, {
+  TestModel.upsert<TestModel>({}, {
     benchmark: true,
     fields: ['testField'],
     hooks: true,
@@ -16,5 +16,26 @@ sequelize.transaction(trx => {
     searchPath: 'DEFAULT',
     transaction: trx,
     validate: true,
-  })
+  }).then((res: [ TestModel, boolean ]) => {});
+
+  TestModel.upsert<TestModel>({}, {
+    benchmark: true,
+    fields: ['testField'],
+    hooks: true,
+    logging: true,
+    returning: false,
+    searchPath: 'DEFAULT',
+    transaction: trx,
+    validate: true,
+  }).then((created: boolean) => {});
+
+  return TestModel.upsert<TestModel>({}, {
+    benchmark: true,
+    fields: ['testField'],
+    hooks: true,
+    logging: true,
+    searchPath: 'DEFAULT',
+    transaction: trx,
+    validate: true,
+  }).then((created: boolean) => {});
 })