Description
unnecesary_duplicate_value
Description
Remove unnecessary ||/&& values to avoid redundancy.
Details
When the || or && operator is used with identical values, leading to redundant code, removing these unnecessary duplicates improves code clarity and reduces potential confusion. By enforcing this lint, developers are encouraged to write more concise and maintainable switch cases, eliminating redundancy without changing the logic of the program. This lint is particularly useful in ensuring that codebases remain clean and that unnecessary conditions do not obscure the intended logic.
Kind
This lint enforces style advice by ensuring more concise and clear code, eliminating redundant conditions in switch cases.
Bad Examples
return switch (value) {
3 || 3 => 1, // Lint should trigger here
_ => 3,
};if (value == 5 || value == 5) { // Lint should trigger here
doSomething();
}if (value == 5 && value == 5) { // Lint should trigger here
doSomething();
}Good Examples
return switch (value) {
3 => 1,
_ => 3,
};if (value == 5) {
doSomething();
}Discussion
Inspired by #59529 for cases of big or expressions where the values might not be exactly side by side and can be hard to spot. Usually, these cases appear when you are doing code refactoring so I believe this could help mainly in those cases.
This could of course have some false negatives but I believe it is best to have some kind of warning than to have none.
If this is ever implemented, I believe this should be added to Effective Dart.
Discussion checklist
- List any existing rules this proposal modifies, complements, overlaps or conflicts with.
- List any relevant issues (reported here, the [SDK Tracker], or elsewhere).
- If there's any prior art (e.g., in other linters), please add references here.
- If this proposal corresponds to [Effective Dart] or [Flutter Style Guide] advice, please call it out. (If there isn't any corresponding advice, should there be?)
- If this proposal is motivated by real-world examples, please provide as many details as you can. Demonstrating potential impact is especially valuable.