add rule no danger props and tests

[VictorHom]

The rule is from here

It's based on the list in #341

Also the credit pretty much goes to @bitpshr in his pr #421

[VictorHom]

@sebmck not sure what the issue is with ci error. can you help me when you have a chance?

[bitpshr]

I think this rule should be considered carefully before it's landed. It's not a recommended rule, it's not used by create-react-app, and the less-restrictive react/no-danger-with-children rule is already implemented. If this rule does end up landing, react/no-danger-with-children should in turn be removed to prevent duplicate warnings when children is also set.

[VictorHom]

@bitpshr good point. not familiar with what's used in react-create-app, but I agree with that the duplicated messaging wouldn't be good

[sebmck]

This looks reasonable. We are going with the strategy of "over the top" lint rules with suppressions preferred. This is one of the things that is wrong 99% of the time. What do you think about the rule overlap?

[bitpshr]

Thinking about this more, rule overlap isn't a bad thing and will happen in other cases, too. For example, duplicate object keys will be checked in addition to duplicate JSX props, even though they technically overlap in the case of createElement. Throwing different (or tangentially-related) errors for the same lines won't hurt anything.

[sebmck]

Sounds good to me. We can fine tune our strategy in the future if it turns out to be excessive.

[sebmck]

Thanks all!