fix(types): allow merge Record and litteral object

Author: avallete

src/types.ts

@@ -131,33 +131,39 @@ export type CheckMatchingArrayTypes<Result, NewResult> =
 
 type Simplify<T> = T extends object ? { [K in keyof T]: T[K] } : T
 
-type MergeDeep<New, Row> = {
-  [K in keyof New | keyof Row]: K extends keyof New
+// Extract only explicit (non-index-signature) keys.
+type ExplicitKeys<T> = {
+  [K in keyof T]: string extends K ? never : K
+}[keyof T]
+
+type MergeExplicit<New, Row> = {
+  // We merge all the explicit keys which allows merge and override of types like
+  // { [key: string]: unknown } and { someSpecificKey: boolean }
+  [K in ExplicitKeys<New> | ExplicitKeys<Row>]: K extends keyof New
     ? K extends keyof Row
       ? Row[K] extends SelectQueryError<string>
         ? New[K]
-        : // Check if the override is on a embeded relation (array)
-        New[K] extends any[]
+        : New[K] extends any[]
         ? Row[K] extends any[]
           ? Array<Simplify<MergeDeep<NonNullable<New[K][number]>, NonNullable<Row[K][number]>>>>
           : New[K]
-        : // Check if both properties are objects omiting a potential null union
-        IsPlainObject<NonNullable<New[K]>> extends true
+        : IsPlainObject<NonNullable<New[K]>> extends true
         ? IsPlainObject<NonNullable<Row[K]>> extends true
-          ? // If they are, use the new override as source of truth for the optionality
-            ContainsNull<New[K]> extends true
-            ? // If the override want to preserve optionality
-              Simplify<MergeDeep<NonNullable<New[K]>, NonNullable<Row[K]>>> | null
-            : // If the override want to enforce non-null result
-              Simplify<MergeDeep<New[K], NonNullable<Row[K]>>>
-          : New[K] // Override with New type if Row isn't an object
-        : New[K] // Override primitives with New type
-      : New[K] // Add new properties from New
+          ? ContainsNull<New[K]> extends true
+            ? Simplify<MergeDeep<NonNullable<New[K]>, NonNullable<Row[K]>>> | null
+            : Simplify<MergeDeep<New[K], NonNullable<Row[K]>>>
+          : New[K]
+        : New[K]
+      : New[K]
     : K extends keyof Row
-    ? Row[K] // Keep existing properties not in New
+    ? Row[K]
     : never
 }
 
+type MergeDeep<New, Row> = Simplify<
+  MergeExplicit<New, Row> & (string extends keyof Row ? { [K: string]: Row[string] } : {})
+>
+
 // Helper to check if a type is a plain object (not an array)
 type IsPlainObject<T> = T extends any[] ? false : T extends object ? true : false
 

test/override-types.test-d.ts

@@ -375,7 +375,10 @@ const postgrest = new PostgrestClient<Database>(REST_URL)
             baz: number
           }
           en: 'ONE' | 'TWO' | 'THREE'
-          record: { baz: 'foo' }
+          record: {
+            [x: string]: Json | undefined
+            baz: 'foo'
+          }
         }
         age_range: unknown
         catchphrase: unknown