Do you think about compatibility of your public API when you modify classes from it? It is especially easy to miss out that something incompatibly changed when you are using Lombok<\/a>. If you use Let’s define simple class with <\/p>\n Now we can use generated constructor in spock test:<\/p>\n And the test is green.<\/p>\n Let’s add new optional field to our Person class – Adding optional field is considered compatible change. But our test fails…<\/p>\n If you still want to use And now our test again passes.<\/p>\n If you use only After adding new field AllArgsConstructor<\/code><\/a> annotation it will cause many problems.<\/p>\nWhat is the problem?<\/h2>\n
AllArgsConstructor<\/code>:<\/p>\n@Data\r\n@AllArgsConstructor\r\npublic class Person {\r\n private final String firstName;\r\n private final String lastName;\r\n private Integer age;\r\n}<\/pre>\ndef 'use generated allArgsConstructor'() {\r\n when:\r\n Person p = new Person('John', 'Smith', 30)\r\n then:\r\n with(p) {\r\n firstName == 'John'\r\n lastName == 'Smith'\r\n age == 30\r\n }\r\n}<\/pre>\nemail<\/code>:<\/p>\n@Data\r\n@AllArgsConstructor\r\npublic class Person {\r\n private final String firstName;\r\n private final String lastName;\r\n private Integer age;\r\n private String email;\r\n}<\/pre>\ngroovy.lang.GroovyRuntimeException: Could not find matching constructor for: com.github.alien11689.allargsconstructor.Person(java.lang.String, java.lang.String, java.lang.Integer)<\/pre>\n
How to solve this problem?<\/h2>\n
After adding field add previous constructor<\/h3>\n
AllArgsConstructor<\/code> you have to ensure compatibility by adding previous version of constructor on your own:<\/p>\n@Data\r\n@AllArgsConstructor\r\npublic class Person {\r\n private final String firstName;\r\n private final String lastName;\r\n private Integer age;\r\n private String email;\r\n\r\n public Person(String firstName, String lastName, Integer age) {\r\n this(firstName, lastName, age, null);\r\n }\r\n}\r\n<\/pre>\nAnnotation
lombok.Data<\/code> is enough<\/span><\/h3>\nData<\/code><\/a> annotation, then constructor, with only mandatory (final<\/code>) fields, will be generated. It is because Data<\/code> implies RequiredArgsConstructor<\/code><\/a>:<\/p>\n@Data\r\npublic class Person {\r\n private final String firstName;\r\n private final String lastName;\r\n private Integer age;\r\n}<\/pre>\nclass PersonTest extends Specification {\r\n def 'use generated requiredFieldConstructor'() {\r\n when:\r\n Person p = new Person('John', 'Smith')\r\n p.age = 30\r\n then:\r\n with(p) {\r\n firstName == 'John'\r\n lastName == 'Smith'\r\n age == 30\r\n }\r\n }\r\n}<\/pre>\nemail<\/code> test still passes.<\/p>\nUse
Builder<\/code> annotation<\/h3>\n