[Fiber] Treat unwrapping React.lazy more like a use() #34031
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| // pre-warming | ||
| 'Foo', | ||
| ]); | ||
| assertLog(['Foo']); |
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Now a Lazy gets to participate in the optimization when it can be immediately resolved in place instead of causing a rerender.
This doesn't have any of the other legacy quirks like infinite pinging concerns since these are unconditionally rendered in the child position and never inside a component render.
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This seems somewhat related to my bug with lazy children in |
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While we want to get rid of React.lazy's special wrapper type and just use a Promise for the type, we still have the wrapper. However, this is still conceptually the same as a Usable in that it should be have the same if you `use(promise)` or render a Promise as a child or type position. This PR makes it behave like a `use()` when we unwrap them. We could move to a model where it actually reaches the internal of the Lazy's Promise when it unwraps but for now I leave the lazy API signature intact by just catching the Promise and then "use()" that. This lets us align on the semantics with `use()` such as the suspense yield optimization. It also lets us warn or fork based on legacy throw-a-Promise behavior where as `React.lazy` is not deprecated. DiffTrain build for [9be531c](9be531c)
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While we want to get rid of React.lazy's special wrapper type and just use a Promise for the type, we still have the wrapper. However, this is still conceptually the same as a Usable in that it should be have the same if you `use(promise)` or render a Promise as a child or type position. This PR makes it behave like a `use()` when we unwrap them. We could move to a model where it actually reaches the internal of the Lazy's Promise when it unwraps but for now I leave the lazy API signature intact by just catching the Promise and then "use()" that. This lets us align on the semantics with `use()` such as the suspense yield optimization. It also lets us warn or fork based on legacy throw-a-Promise behavior where as `React.lazy` is not deprecated. DiffTrain build for [9be531c](9be531c)
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While we want to get rid of React.lazy's special wrapper type and just use a Promise for the type, we still have the wrapper.
However, this is still conceptually the same as a Usable in that it should be have the same if you
use(promise)or render a Promise as a child or type position.This PR makes it behave like a
use()when we unwrap them. We could move to a model where it actually reaches the internal of the Lazy's Promise when it unwraps but for now I leave the lazy API signature intact by just catching the Promise and then "use()" that.This lets us align on the semantics with
use()such as the suspense yield optimization. It also lets us warn or fork based on legacy throw-a-Promise behavior where asReact.lazyis not deprecated.