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{#key} not working inside {#each}/{#if}

See original GitHub issue

Describe the bug

{#key} and its body that work doesn’t work inside {#each} block.

I want to display the duration passed every second by calculation instead of assigning a value to an object in an array and triggering update with assignment.

Reproduction

https://svelte.dev/repl/d4112f1ae05046bdb48be42b62cc4c8d?version=3.42.4

Logs

No response

System Info

System:
    OS: Windows 10 10.0.18363
    CPU: (8) x64 Intel(R) Core(TM) i7-3610QM CPU @ 2.30GHz
    Memory: 6.11 GB / 11.90 GB
  Binaries:
    Node: 14.16.0 - D:\Program Files\nodejs\node.EXE
    npm: 6.14.11 - D:\Program Files\nodejs\npm.CMD
  Browsers:
    Chrome: 91.0.4472.164
    Edge: Spartan (44.18362.1533.0)
    Internet Explorer: 11.0.18362.1
  npmPackages:
    svelte: ^3.38.2 => 3.38.2

Severity

annoyance

Issue Analytics

State:
Created 2 years ago
Reactions:2
Comments:10 (6 by maintainers)

Top GitHub Comments

1reaction

dummdidummcommented, Apr 29, 2022

It was, thanks for noticing!

1reaction

Prinzhorncommented, Aug 28, 2021

This does work in contrast (I simply output the key {force_update_heartbeat}): https://svelte.dev/repl/d2358d0e2e9c4052afad3ec85140802b?version=3.42.4 So it seems like Svelte does not add the key to the observed properties when inside each. But if it is there anyway the update works.

Edit: even with the bug fixed your REPL doesn’t look Svelte-like to me. You are basically imperatively controlling the reactivity by setting force_update_heartbeat just to call foo(). If you can show a more real world example I’m sure there is a better way. Why not update the array items directly each tick? https://svelte.dev/repl/dc3ac91d693a466693a1935a96d06c73?version=3.42.4