Description
Describe the bug
Certain component filenames will throw the error: Could not derive component name from file {FILENAME}.svelte.
Examples of filenames that will throw an error:
@.svelte
&.svelte
...
Examples of filenames that will not throw an error:
%.svelte
$.svelte
The reason for why this is happening is that function get_name_from_filename replaces certain characters with underscores and if these underscores happen to be leading characters, then they get deleted.
The behavior is somewhat inconsistent, because certain equivalent filenames, but with a different special character do work just fine.
Additionally, this is not how HTML and the web generally work. You may very well have a file named just "@" if you want.
This is a bigger issue in SvelteKit, because now urls like example.com/something/@ are essentially second class citizens (yes the problem can be fixed by creating a directory and a index.svelte file, but this is in some cases extra boilerplate).
Potential fix
It is relatively easy to fix this problem. In the function get_name_from_filename the following code is the culprit:
const base = parts.pop()
.replace(/%/g, 'u')
.replace(/\.[^.]+$/, '')
.replace(/[^a-zA-Z_$0-9]+/g, '_') // This line replaces "@" => "_"
.replace(/^_/, '') // This line replaces leading "_" => "" and thus causes the bug
.replace(/_$/, '')
.replace(/^(\d)/, '_$1');
To fix this problem, either change .replace(/%/g, 'u') to take in other special characters as well, like so: .replace(/[%@#]/g, 'u'). However, this leads to the question of what special characters are to be supported. Maybe there is some way to regex them all? Additionally, should all of these be replaced with "u"?
Alternatively, leading "_" should not be discarded if they are the only characters.
Reproduction
https://svelte.dev/repl/392f9371025f48f88a6274a5f6e6d8ee?version=3.46.2
Logs
Could not derive component name from file @.svelteSystem Info
REPLSeverity
annoyance