quoted method names are treated as undefined when validating / checking for duplicates

[m59peacemaker]

This is broken:

methods: {
  'foo': () => {},
  'bar': () => {}
}

REPL

Stack Trace

bundle.35d793bc40a79d89436e63d8b274bfd88d0208bd.js:1 ValidationError: Duplicate property 'undefined' at ValidationError.CompileError [as constructor] (https://unpkg.com/svelte@1.41.2/compiler/svelte.js:11347:28) at new ValidationError (https://unpkg.com/svelte@1.41.2/compiler/svelte.js:12555:28) at Validator.error (https://unpkg.com/svelte@1.41.2/compiler/svelte.js:12576:15) at https://unpkg.com/svelte@1.41.2/compiler/svelte.js:11501:23 at Array.forEach () at checkForDupes (https://unpkg.com/svelte@1.41.2/compiler/svelte.js:11499:16) at methods (https://unpkg.com/svelte@1.41.2/compiler/svelte.js:11685:5) at https://unpkg.com/svelte@1.41.2/compiler/svelte.js:12067:21 at Array.forEach () at https://unpkg.com/svelte@1.41.2/compiler/svelte.js:12064:41

Admittedly, I encountered this whilst trying to hack svelte's static analysis of my method names. So, perhaps it is best that method names are not permitted to be quoted. I need to call some functions that are created at runtime, so I did this in oncreate this.someFunctions = makeSomeFunctions(args), in the view on:stuff="someFunctions.foo()", and methods: { 'someFunctions.foo': noop }`. It was just a thought to get svelte to stop yelling at me. But quite hacky. Maybe it is good to prevent me and everyone from doing this.

[m59peacemaker]

If we do want quoted method names to work, I can probably do the PR.

[Conduitry]

I was just doing some poking around, and this seems to be an issue in a number of other places as well. When traversing the AST and looking at the properties of an ObjectExpression, Svelte looks at prop.key.name because it's expecting prop.key to be an Identifier. With quoted properties, prop.key is a Literal and what we want to be looking at is prop.key.value.

We could probably do with some common helper function that extracts the name for Identifier props, and extracts the value for string Literal props, and throws an error for other node types. The more challenging part is probably going to be finding all of the places where we need to watch out for this. Even if we wanted to disallow quoted keys, it'd still be almost as much work, since we'd need to hunt down all of these instances anyway. So I'd vote we might as well support literal string property keys.

As for the original issue you were trying to work around, it seems like we could get at that in a couple different ways - One by making it easier to ignore specific warnings (#824) - Or by providing some way in the component definition export default { ... } to specify additional methods (maybe with wildcards?) that Svelte shouldn't warn about being undefined.

[Rich-Harris]

This is fixed in 1.42. For the warnings, I think #824 is the way to go