Implement DON’T discard errors from catches without on clauses.

[JPaulsen]

From Effective Dart

[JPaulsen]

@bwilkerson @pq is this necessary to implement? Because if you have something like this.

try {
}
catch(e) {
  // ignore
}

The analyzer will say: "The exception variable 'e' is not used, so the 'catch' clause can be removed."

[zoechi]

I don't get a hint for the unused variable 'e' with above code.

I also don't get any hint for

try {
}
catch(_) {}

[bwilkerson]

There is no hint when the exception parameter is not used and there is no on clause because at that point the exception parameter is required and there isn't any reasonable way the user could get rid of the hint.

is this necessary to implement?

How would you catch this case? Any exception parameter that is not referenced within the catch clause? It will be marked as dead code if there is an on clause, and I don't think it's useful to create a lint that cannot be removed. I don't think we need a lint for this.

[JPaulsen]

You were right, without on clauses it does not hint that.

And yes, if it has the on clause it will be mark as dead code, and without the on will be linted as avoid lints without on, so I will close this issue.