test: improve test locality #188
Description
At least, we need to increase test locality moving arrange-act-assert pattern within one test method or at most in one test class for the reused arrangements (@ before / @ after).
An example of a test class structure:
@DisplayName("A resultSet")
class SelectOperationIT {
// text fixture
Statement statement;
...
// reused for each test preparations
@BeforeEach
public void setUp() throws Exception {
statement.executeUpdate("CREATE TABLE test (id INT PRIMARY KEY, val VARCHAR(50))");
}
// cleanup garbage after the test execution
@AfterEach
public void tearDown() throws Exception {
statement.executeUpdate("DROP TABLE test");
}
@Test
@DisplayName("fetched one row by id = 1")
public void testOneRowSelect() {
// arrange (given)
String insertQuery = "INSERT INTO test VALUES (1, 'a');
statement.executeUpdate(insertQuery);
// act (when)
String selectQuery = "SELECT * FROM test WHERE id = 1";
ResultSet resultSet = statement.executeUpdate(selectQuery);
resultSet.next();
// assert (then)
int expectedResultId = 1;
String expectedResultValue = "a";
assertEquals(expectedResultId, result.getInt(1));
assertEquals(expectedResultValue, result.getString(2));
}
...
}