Inconsistent spacing between two copies of same code

[ezfe]

Describe the bug

Spaces are added to the Svelte output causing the rendered text not to appear as expected (for example, looping over and outputting characters in a string).

To Reproduce

REPL: https://svelte.dev/repl/86aa94c8350845e794b27ea9f75624e9?version=3.35.0

<script>
	let name = 'Hello world';
</script>

{#each name as character}
	<span>
		{#if character == "l"}
			A
		{:else}
			B
		{/if}
	</span>
{/each}

{#each name as character}
	<span>
		{#if character == "l"}
			A
		{:else}
			B
		{/if}
	</span>
{/each}

Expected behavior
There should be no spaces in the output.

• Your browser and the version: (e.x. Chrome 52.1, Firefox 48.0, IE 10)

Safari 14.1
Edge 89.0.774.57

• Your operating system: (e.x. OS X 10, Ubuntu Linux 19.10, Windows XP, etc)

macOS 11

• Svelte version (Please check you can reproduce the issue with the latest release!)

Svelte 3.35.0

• Whether your project uses Webpack or Rollup

Rollup, reproduced with Repl

Severity
How severe an issue is this bug to you? Is this annoying, blocking some users, blocking an upgrade or blocking your usage of Svelte entirely?

This bug is blocking a secondary feature of my website. I am building a preview of formatted text, and need to be able to loop over text and show each one in its own <span>. Only spaces in the source text should appear in the HTML.

[Prinzhorn]

Curiously this only happens in the very last block. If you repeat it more than two times it's always the last block. And if you add anything after the each block the space disappears. I hope this helps.

No spaces because of the "x" at the end:

<script>
	let name = 'Hello world';
</script>

{#each name as character}
	<span>
		{#if character == "l"}
			A
		{:else}
			B
		{/if}
	</span>
{/each}

{#each name as character}
	<span>
		{#if character == "l"}
			A
		{:else}
			B
		{/if}
	</span>
{/each}

{#each name as character}
	<span>
		{#if character == "l"}
			A
		{:else}
			B
		{/if}
	</span>
{/each}

x

[ezfe]

Yea, I actually noticed that after filing but forgot to come back and add it in. It's super variable, (if of course not actually random).

[stalkerg]

Also, we still have these issues #4731 and #189

[stalkerg]

heh this space exists but not working inside Svelte runtime tests

[ezfe]

I found a REPL that actually identifies the same issue: https://svelte.dev/repl/b6c71bf8825f46028793d804facf5e08?version=3.5.1

[stalkerg]

@ezfe I think is different issue

[stalkerg]

ok, I know why it's happens

[stalkerg]

because the first \n (actually something more) between two Fragments (each) we can remove, but the last \n have no obvious reasons to remove.
This part in compiler a little tricky... basically here we can see some inconsistency between the parser and internal compiler AST.
I will try to find way to solve it.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[dummdidumm]

Svelte 5 does whitespace trimming a bit differently, and therefore this issue is fixed