saqel/backend/.agents/skills/testing-best-practices/rules/security.md

Security Tests

Test each security boundary where user input affects authorization, rendered output, or query construction. A defect at such a boundary can be difficult to detect because the feature may continue to work.

Write a test for each of these cases:

• Cross-tenant access. Request a record of a different tenant, team, or organization. Read rules/endpoint-tests.md for why the response should be 404 rather than 403.
• Each unprivileged role. Use a data provider over the roles that the endpoint must refuse.
• Escaping user-provided content. Test escaping in HTML and mail. Include names and every free-text field a template renders. Assert that dangerous characters are escaped and the raw value is absent. Do not assert an exact entity for a quote, because Markdown and mail CSS inliners may decode it.
• Injection into dynamic query components. Examples include sort columns, filter fields, and sort directions.
• An unexpected key in a payload or configuration array. A merge that accepts every key can set an attribute the user must not control.

public function test_escapes_dangerous_content_in_the_notification(): void
{
    $organization = Organization::factory()->make([
        'name' => "O'Reilly <script>alert('xss')</script>",
    ]);

    $content = (new QuotaApproaching($organization, 80))->toMail()->render();

    $this->assertStringContainsString('<script>', $content);
    $this->assertStringNotContainsString("<script>alert('xss')</script>", $content);
}

Laravel provides defenses against mass assignment, unauthorized access, and unescaped output. Test that the application applies the appropriate defense to each attribute, route, and template.