feat: add query result type helpers. (#918)

* feat: add query result type helpers.

* chore: update naming for consiceseness.

Author: thorwebdev

src/index.ts

@@ -17,7 +17,7 @@ export {
 } from '@supabase/functions-js'
 export * from '@supabase/realtime-js'
 export { default as SupabaseClient } from './SupabaseClient'
-export type { SupabaseClientOptions } from './lib/types'
+export type { SupabaseClientOptions, QueryResult, QueryData, QueryError } from './lib/types'
 
 /**
  * Creates a new Supabase Client.

src/lib/types.ts

@@ -1,5 +1,6 @@
 import { GoTrueClient } from '@supabase/gotrue-js'
 import { RealtimeClientOptions } from '@supabase/realtime-js'
+import { PostgrestError } from '@supabase/postgrest-js'
 
 type GoTrueClientOptions = ConstructorParameters<typeof GoTrueClient>[0]
 
@@ -95,3 +96,10 @@ export type GenericSchema = {
   Views: Record<string, GenericView>
   Functions: Record<string, GenericFunction>
 }
+
+/**
+ * Helper types for query results.
+ */
+export type QueryResult<T> = T extends PromiseLike<infer U> ? U : never
+export type QueryData<T> = T extends PromiseLike<{ data: infer U }> ? Exclude<U, null> : never
+export type QueryError = PostgrestError