DT nightly: many new excessively deep instantiation errors

[sandersn]

Could be the result of a react-redux change, but we should have caught it in CI then.

• fluent-react
• mirrorx
• next-redux-saga
• next-redux-wrapper
• react-intl-redux
• react-lifecycle-component

Running tsc from react-lifecycle-component, next-redug-saga or mirrorx gives:

../react-redux/index.d.ts:113:61 - error TS2589: Type instantiation is excessively deep and possibly infinite.

113     ) => ConnectedComponentClass<C, Omit<GetProps<C>, keyof Shared<TInjectedProps, GetProps<C>>> & TNeedsProps>;
                                                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Same for fluent-react, except the invocation is in its own code.

Unsurprisingly, doesn't repro on 3.3.3333. Edit: Haven't tried to bisect it though.

[sandersn]

@weswigham Mind taking a look while @ahejlsberg is out?

[weswigham]

Cause looks to be #30334 - reverting it removes the error.

[weswigham]

TFW a seemingly innocent refactoring breaks the world. 😿

[RyanCavanaugh]

TFW a seemingly innocent refactoring breaks the world

0 baselines changed, we have great coverage, must be good right

[ahejlsberg]

See #30334 for the real fix for this issue.

[Veetaha]

If I am not mistaken, you limit type nesting level to 50, but this is really too tight, I wish there was no limit at all, but currently this error has appeared in my library code in 3.4.0-dev.20190322. It is so tight that when I manually expand one level of my type the error goes away.

Demonstration

Foo fails, but Bar doesn't, even though they are the same, except Bar has one level of indirection less.

Original code