feat(types): add json path type inference

[avallete]

What kind of change does this PR introduce?

Allow users to override Json type with custom types, and take into account the "json accessor" to infer the proper resulting type.

What is the current behavior?

Given a table defined like so:

type CustomJsonType = {
  foo: string
  bar: {
    baz: number
  }
  en: 'ONE' | 'TWO' | 'THREE'
}
table: {
 data: CustomJsonType | null
}

The following behavior is observed:

select(`data`) -> {data: CustomJsonType | null}
select(`data->bar`) -> {bar: Json}
select(`data->>bar`) -> {bar: string}
select(`data->>en`) -> {bar: string}
select(`data->bar->baz`) -> {baz: Json}

What is the new behavior?

select(`data`) -> {data: CustomJsonType | null}
select(`data->bar`) -> { bar:  { baz: number } }
// Preserve the postgrest casting behaviour due to ->> accessor
select(`data->>bar`) -> {bar: string}
// Preserve the union of string
select(`data->>en`) -> {bar:  'ONE' | 'TWO' | 'THREE'}
// Preserve the accessed ressource type
select(`data->bar->baz`) -> {baz: number}
// Fallback on the default behavior for non-matching properties
select(`data->bar->nope`) -> {nope: Json}
select(`data->bar->>nope`) -> {nope: string}

Additional context

Add any other context or screenshots.

[avallete]

We use this to format and save the value "path accessor" information from the parser to the result inference. That way, the parser can still be agnostic to the database types, only caring about string parsing.

[avallete]

Turn something like data->some->>property into some.property

[avallete]

Parse some path like some.property and try to match it with the type T provided.

[avallete]

Here for some reason (maybe TS upgrade) using this syntax:

const { data, error } = await ...

if (error) {
 throw XXX
}
// here data was still of type data[] | null
// because typescript seemed to fail to understand the branching

Changing to this syntax properly narrow down result.data as non nullable once we checked the error.

[kamilogorek]

That's already a black-magic level, but validated behavior on our live project and everything works as expected.

[kamilogorek]

Gentle ping @soedirgo

[soedirgo]

Seems to not work on embedded tables:

    const result = await postgrest
      .from('messages')
      .select('users(data->bar)')

(I updated the types for public.users.data with CustomUserDataType)

But that can be handled in a separate PR 👍