WIP: proper types for `objectToCamelCase`

package.json

@@ -124,6 +124,7 @@
     "eslint-plugin-vue": "9.9.0",
     "happy-dom": "8.9.0",
     "histoire": "0.15.8",
+    "literal-case": "^1.0.0",
     "netlify-cli": "13.1.2",
     "postcss": "8.4.21",
     "postcss-easing-gradients": "3.0.1",

pnpm-lock.yaml

@@ -64,6 +64,7 @@ specifiers:
   histoire: 0.15.8
   is-touch-device: 1.0.1
   klona: 2.0.6
+  literal-case: ^1.0.0
   lodash.debounce: 4.0.8
   marked: 4.2.12
   netlify-cli: 13.1.2
@@ -177,6 +178,7 @@ devDependencies:
   eslint-plugin-vue: 9.9.0_eslint@8.36.0
   happy-dom: 8.9.0
   histoire: 0.15.8_mbllq5flobsmlktljlyrk4fpme
+  literal-case: 1.0.0
   netlify-cli: 13.1.2_@types+node@18.15.1
   postcss: 8.4.21
   postcss-easing-gradients: 3.0.1
@@ -10278,6 +10280,10 @@ packages:
       wrap-ansi: 7.0.0
     dev: true
 
+  /literal-case/1.0.0:
+    resolution: {integrity: sha512-uJJFKXDMip5SraJINCO0as7guJkbMR1iVSkTpYIXaD6eaFuggskZyKcuAWYQJyJYoD39MWiAIPxTf/TystKq/g==}
+    dev: true
+
   /local-pkg/0.4.2:
     resolution: {integrity: sha512-mlERgSPrbxU3BP4qBqAvvwlgW4MTg78iwJdGGnv7kibKjWcJksrG3t6LB5lXI93wXRDvG4NpUgJFmTG4T6rdrg==}
     engines: {node: '>=14'}

src/helpers/case.ts

@@ -1,10 +1,50 @@
-import {camelCase} from 'camel-case'
-import {snakeCase} from 'snake-case'
+import {camelCase as camelCaseUntyped} from 'camel-case'
+import {snakeCase as snakeCaseUntyped} from 'snake-case'
+import type {
+	camelCase as camelCaseTyped,
+	snakeCase as snakeCaseTyped,
+	CamelCase,
+	SnakeCase,
+} from 'literal-case'
+
+const camelCase = camelCaseUntyped as typeof camelCaseTyped
+const snakeCase = snakeCaseUntyped as typeof snakeCaseTyped
+
+// type ObjectToCamelCase<T> = {
+// 	[P in keyof T as (P extends string
+// 		? CamelCase<P>
+// 		: P
+// 	)]: T[P] extends (Record<string, unknown> | unknown[])
+// 		? ObjectToCamelCase<T[P]>
+// 		: T[P]
+// }
+type NestedObjectsToCamelCase<
+	// T extends (Record<string, unknown> | unknown[])
+	T
+> = T extends unknown[]
+	? {
+		// Change array elements while keeping prototype properties the same.
+		[P in keyof T]: P extends number
+			? NestedObjectsToCamelCase<T[P]>
+			: T[P]
+	}
+	// TODO what about class instances here? Methods would also get transformed. Is it right?
+	// : T extends Record<string, any>
+	: T extends Record<string, unknown>
+	? {
+		[P in keyof T as (P extends string
+			? CamelCase<P>
+			: P
+		)]: NestedObjectsToCamelCase<T[P]>
+	}
+	: T
 
 /**
  * Transforms field names to camel case.
  */
-export function objectToCamelCase(object: Record<string, any>) {
+export function objectToCamelCase<T extends Record<string, any>>(
+	object: T,
+): NestedObjectsToCamelCase<T> {
 
 	// When calling recursively, this can be called without being and object or array in which case we just return the value
 	if (typeof object !== 'object') {