Nathan Shively-Sanders 1cf9a73832 Signature help: support non-trailing rest parameters ...

In signature help, the first rest parameter will always be the *last*
'current' parameter (disregarding types). Previously, the signature help
current-parameter highlight was only correct for trailing rest
parameters. However, with tuple types, you can now create non-trailing
rest parameters. This PR now correctly highlights non-trailing rest
parameters as the last 'current' parameter.

For example, `names` should be the current parameter in all the calls
below:

```ts
declare function loading(...args: [...names: string[], allCaps: boolean, extra: boolean]): void;

leading(/**/
leading('one', /**/
leading('one', 'two', /**/
```

And, because signature help doesn't do real overload resolution, `names`
is also the current parameter for other calls:

```ts
leading(1, 2, 3, 'ill-typed', /**/
leading('fine', true, /**/
```

2021-02-01 14:42:31 -08:00

..

baselines/reference

Don’t create missing nodes for identifiers that would be valid in a newer script target (#42520)

2021-01-29 14:10:29 -08:00

cases

Signature help: support non-trailing rest parameters

2021-02-01 14:42:31 -08:00

lib

Preserve alias information where possible when looking up union and intersection base constraints (#42430)

2021-01-21 13:06:56 -08:00

projects

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