Preact support: Check for empty array children #4423
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Ah, awesome thanks for doing that @kwelch. |
| <Route path="/" render={() => ( | ||
| <h1>{TEXT}</h1> | ||
| )}> | ||
| {[]} |
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The way this test is written should trigger this warning, because you're using both the <Route render> and <Route children> props. Let's just get rid of the test and put a note in the code.
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Oh wait, duh. Of course the warning isn't firing because you null out children before we get that far. Ignore me :)
Question: does Preact always give you a children prop, @developit? i.e. if I render a component w/out any children like <MyComponent/> does Preact give me an empty children array?
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@mjackson yes. props.children is always a (flattened) Array in Preact, with empties removed and adjacent Strings merged. The empty children Array is always the same shared reference to an empty Array so that shallowEqual checks within shouldComponentUpdate will correctly ignore repeated empty children (for leaf nodes).
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Thanks, @kwelch and @developit! 💯 |
Duplicate of #4402, I added in a test.
I didn't have write access to @developit's branch so I made a fork.
Not sure if there is a different/better way to approach this test, but it seemed right to me.