Supabase improperly types postgrest computed relationships

[gwax]

Bug report

• I confirm this is a bug with Supabase, not with my own application.
• I confirm I have searched the Docs, GitHub Discussions, and Discord.

Describe the bug

Supabase supports making calls using postgrest computed relationships: https://postgrest.org/en/v12/references/api/resource_embedding.html#computed-relationships

However, these show up as typescript errors of the form SelectQueryError<"could not find the relation between ...">

The types for computed relationships (mostly) worked in 2.47.7 but broke starting in 2.47.8

To Reproduce

Minimal reproduction is available in the gwax/computed-relationships branch here: https://github.com/manapoolinc/supabase-playground/tree/gwax/computed-relationships

1. Create a computed relationship: https://github.com/manapoolinc/supabase-playground/blob/gwax/computed-relationships/supabase/migrations/20250127194033_create_country_fns.sql#L1
2. Use the computed relationship in a query: https://github.com/manapoolinc/supabase-playground/blob/gwax/computed-relationships/src/lib/db/countries.ts#L47
3. See type error in IDE / typescript compiler: https://github.com/manapoolinc/supabase-playground/blob/gwax/computed-relationships/src/lib/db/countries.ts#L101

Expected behavior

No Type Errors in reproduction code

System information

• Version of supabase: 2.6.8
• Version of supabase-js: 2.48.1

[stefan-girlich]

Thanks for documenting this issue! I've been using a custom utility type to manually override the faulty type, but it has become a burden for deeply embedded resources - see the code below.

I am exploring how to improve the utility, but I hope a native solution is possible.

Show code applying custom utility type

type RawCustomerContractLineItem = NonNullable<
  typeof rawData
>['customer_contract_line_items'][number]
type RawLineItemToPurchaseAssignment =
  RawCustomerContractLineItem['customer_contract_line_items__token_purchases'][number]
type RawTokenPurchase = RawLineItemToPurchaseAssignment['token_purchases']
type RawBatch = RawTokenPurchase['batches_flat']
type RawOutputFraction = RawBatch['output_fractions'][number]

type Result = FixSupabaseQueryDataSingle<
  typeof rawData,
  'customer_contract_line_items',
  {
    customer_contract_line_items: FixSupabaseQueryDataSingle<
      RawCustomerContractLineItem,
      'customer_contract_line_items__token_purchases',
      {
        customer_contract_line_items__token_purchases: FixSupabaseQueryDataSingle<
          RawLineItemToPurchaseAssignment,
          'token_purchases',
          FixSupabaseQueryDataSingle<
            RawTokenPurchase,
            'batches_flat',
            {
              batches_flat: FixSupabaseQueryDataSingle<
                RawBatch,
                'output_fractions',
                FixSupabaseQueryDataSingle<
                  RawOutputFraction,
                  'output_materials',
                  {
                    output_materials: {
                      id: string
                      name: string
                    }
                  }
                >
              >
            }
          >
        >[]
      }
    >[]
  }
>