Nathan Shively-Sanders c3c6be6618 In JSDoc, parse postfix-? below conditional types/tuple types (#39123) ...

Outside of JSDoc comments, postfix-? is parsed at lower precedence than
the `?` of conditional types, and a postfix-? inside a tuple type
results in the type being marked optional.

This PR changes JSDoc parsing to behave the same way, which means that

1. Conditional types are allowed in JSDoc. Fixes #37166.
2. Tuple types' postfix-? syntax is interpreted correctly in JSDoc.
Fixes #38747.

The breaking change is that a postfix-? type followed by another postfix type,
like `[]` or `!`, is parsed as a conditional type. [Postfix-? is not
common](https://github.com/microsoft/TypeScript/issues/37166#issuecomment-612274456),
so this is an acceptable breaking change.

A postfix-? type `T?` is still parsed everywhere else and treated as `T | null`.

2020-06-17 14:06:39 -07:00

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In JSDoc, parse postfix-? below conditional types/tuple types (#39123)

2020-06-17 14:06:39 -07:00

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In JSDoc, parse postfix-? below conditional types/tuple types (#39123)

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