Support completions that require changing from dot to bracket access

[ghost]

Fixes #19433
Must wait on microsoft/vscode#39893 first.

This adds a completion for a property even if it can't follow a . -- and adds a code action to change the style from x.| to x["|"].

[ghost]

@mjbvz I just pushed a commit using replacementSpan and insertText (ref: #20730).

[DanielRosenwasser]

As I mentioned last week, there are people who've been using spaces in names to use as part of type system hacks to have pseudo-private members. Now something that starts with a space will bubble to the top.

@RyanCavanaugh had an idea of excluding names that are spaces, but we could generalize to any character that isn't a valid IdentifierStart

I think another idea might be is to de-prioritize names that aren't valid property accesses.

[DanielRosenwasser]

If we ever want to support completing strings in object literals (without users needing to explicitly type in a quote character), does it make sense to call this something else?

[ghost]

It depends on whether we will still want a flag for the behavior of completing bracketed expressions, or if this will only be used in a non-user-facing way as an editor feature flag. I believe vscode had plans to make a user-facing options for includeExternalModuleExports in case some people don't want that.

[mjbvz]

Yes we have an option for includeExternalModuleExports. However I think we would always want to enable includeBracketCompletions or whatever this new option is called. This flag is useful for backwards compatibility (see #20730) so that we don't break clients that don't support insertText

[ghost]

@DanielRosenwasser We could set sortText to a different value for anything that needs brackets, would that work?

[mhegazy]

We could set sortText to a different value for anything that needs brackets, would that work?

I do not think this is a good idea. from a user perspective, there are searching for "foo bar" no reason why this should not next to "foo" just because when they commit it it becomes ["foo bar"] and not .foo.

We can filter out things that start with at least one sapace.. it is not common for property names to be written that way.

[mhegazy]

We need to filter out the ones that start with spaces as discussed earlier.

[ghost]

@mhegazy @DanielRosenwasser Good to go?

[mhegazy]

//cc @chuckjaz