system/Validation/FileRules.php
public function uploaded(string $blank = null, string $name, array $data): bool
	{
		$file = $this->request->getFile($name);

		if (is_null($file))
		{
			return false;
		}

		if (ENVIRONMENT === 'testing')
		{
			return $file->getError() === 0;
		}

		// Note: cannot unit test this; no way to over-ride ENVIRONMENT?
		// @codeCoverageIgnoreStart
		return $file->isValid();
		// @codeCoverageIgnoreEnd
	}
public function uploaded(string $blank = null, string $name, array $data): bool
	{
		$file = $this->request->getFile($name);

		if (is_null($file))
		{
			return false;
		}

		if (ENVIRONMENT === 'testing')
		{
			return $file->getError() === 0;
		}

		// Note: cannot unit test this; no way to over-ride ENVIRONMENT?
		// @codeCoverageIgnoreStart
		return $file->isValid();
		// @codeCoverageIgnoreEnd
	}
Verifies that $name is the name of a valid uploaded file.

@param string $blank
@param string $name
@param array  $data

@return boolean