ishangsf/rspec
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Modify rule S1206: "equals(Object obj)" and "hashCode()" should be overridden in pairs (hash_and_equals)

Browse Source
This commit is contained in:
Antonio Aversa 2024-07-23 15:22:06 +02:00
parent 81a624d470
commit abcf7a1edf
1 changed files with 38 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
rules/S1206/dart/rule.adoc
View File

@ -1,15 +1,23 @@
== Why is this an issue? == Why is this an issue?
In Dart, you must override either both or neither of the operator `==` and `hashCode()` method in order to keep the contract between the two: In Dart, you must override either both or neither of the operator `==` and the `hashCode()` method.
- Whenever the `hashCode` method is invoked on the same object more than once, it must consistently return the same integer, provided no information used in `==` comparisons on the object is modified. That is required to keep the contract between the two:
- If two objects are equal according to the `==` operator, then calling the `hashCode` method on each of the two objects must produce the same integer result.
* whenever the `hashCode` method is invoked on the same object more than once, it must consistently return the same integer, provided no information used in `==` comparisons on the object is modified
* if two objects are equal according to the `==` operator, then calling the `hashCode` method on each of the two objects must produce the same integer result
By overriding only one of the two methods with a non-trivial implementation, this contract is almost certainly broken. By overriding only one of the two methods with a non-trivial implementation, this contract is almost certainly broken.
=== Exceptions
The rule does not raise in mixins, because they are not supposed to be instantiated directly, but rather included in other classes.
The rule raises, however, on mixin classes, since they can also be used as normal classes, and instantiated directly.
=== Noncompliant code example === Noncompliant code example
[source,dart] [source,dart,diff-id=1,diff-type=noncompliant]
---- ----
class A { class A {
final int value; final int value;
@ -22,7 +30,7 @@ class A {
=== Compliant solution === Compliant solution
[source,dart] [source,dart,diff-id=1,diff-type=compliant]
---- ----
class A { class A {
final int value; final int value;
@ -38,4 +46,28 @@ class A {
== Resources == Resources
* https://dart.dev/tools/linter-rules/unnecessary_overrides[Dart Lint rule] * Dart Docs - https://dart.dev/tools/linter-rules/hash_and_equals[Dart Linter rule - hash_and_equals]
* Dart Docs - https://dart.dev/language/mixins[Language - Classes & objects - Mixins]
ifdef::env-github,rspecator-view[]
'''
== Implementation Specification
(visible only on this page)
=== Message
* Missing a corresponding override of 'hashCode'.
* Missing a corresponding override of '=='.
=== Highlighting
The identifier of the overridden method: either `==` or `hashCode`.
'''
== Comments And Links
(visible only on this page)
include::../comments-and-links.adoc[]
endif::env-github,rspecator-view[]