convert(100, 1, 2); $this->assertIsFloat($converted_amount); } public function testExchangeRate() { $converter = new CurrencyApi(); $exchange_rate = $converter->exchangeRate(1, 2); $this->assertIsNumeric($exchange_rate); } public function testExchangeRateWithDate() { $date = Carbon::parse('2020-03-08'); $converter = new CurrencyApi(); $exchange_rate = $converter->exchangeRate(1, 2, $date); $this->assertIsNumeric($exchange_rate); } }