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Linq mutator

See original GitHub issue

We would like to add a new mutator that mutates Linq queries. It should look for specific methods and replace them with their counterpart or remove them. The following methods should be mutated:

Original	Mutated
`Distinct()`
`Reverse()`
`OrderBy()`
`OrderByDescending()`
`SingleOrDefault()`	`FirstOrDefault()`
`FirstOrDefault()`	`SingleOrDefault()`
`First()`	`Last()`
`Last()`	`First()`
`All()`	`Any()`
`Any()`	`All()`
`Skip()`	`Take()`
`Take()`	`Skip()`
`SkipWhile()`	`TakeWhile()`
`TakeWhile()`	`SkipWhile()`
`Min()`	`Max()`
`Max()`	`Min()`
`Sum()`	`Count()`
`Count()`	`Sum()`

Issue Analytics

State:
Created 5 years ago
Comments:8 (8 by maintainers)

Top GitHub Comments

1reaction

richardwerkmancommented, Oct 12, 2018

Well, I don’t think we can detect Linq Syntax, since it’s not an actual C# kind. We can only detect the name of methods. In this case I think it’s oke to assume that every method with the IdentifierName “All” is an Linq all method. The only way to know that for sure is by reading the semantic model.

We chose not to create an semantic model for each file since this is an expensive operation. We chose to mutate everything we can, while trusting the RollBack mechanism to resolve our “broken mutations”.

So if your mutator wrongly mutates an “All()” invocation, we can trust Stryker to handle this.

I hope this helps!

0reactions

rouke-broersmacommented, Oct 19, 2018

Implemented by #185

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