auditSync - writes an empty array when there is no data change about laravel-auditing

[erikn69]

It is an expected behavior

laravel-auditing/tests/Functional/AuditingTest.php

Lines 634 to 653 in 7d929c0

	public function itWillAuditSyncWithoutChanges()
	{
	$firstCategory = factory(Category::class)->create();
	$article = factory(Article::class)->create();
	$article->categories()->attach($firstCategory);
	$no_of_audits_before = Audit::where('auditable_type', Article::class)->count();
	$categoryBefore = $article->categories()->first()->getKey();
	$article->auditSync('categories', [$firstCategory->getKey()]);
	$no_of_audits_after = Audit::where('auditable_type', Article::class)->count();
	$categoryAfter = $article->categories()->first()->getKey();
	$this->assertSame($firstCategory->getKey(), $categoryBefore);
	$this->assertSame($firstCategory->getKey(), $categoryAfter);
	$this->assertSame($categoryBefore, $categoryAfter);
	$this->assertGreaterThan($no_of_audits_before, $no_of_audits_after);
	}

Try this

laravel-auditing/config/audit.php

Lines 89 to 107 in 7d929c0

	/*
	|--------------------------------------------------------------------------
	| Empty Values
	|--------------------------------------------------------------------------
	|
	| Should Audit records be stored when the recorded old_values & new_values
	| are both empty?
	|
	| Some events may be empty on purpose. Use allowed_empty_values to exclude
	| those from the empty values check. For example when auditing
	| model retrieved events which will never have new and old values.
	|
	|
	*/
	'empty_values' => true,
	'allowed_empty_values' => [
	'retrieved'
	],