Makes ToEncryptPaths type safe and fix bug founds thx to it

packages/gated-content/package.json

@@ -45,7 +45,7 @@
   },
   "license": "MIT",
   "dependencies": {
-    "@lens-protocol/metadata": "0.1.0-alpha.11",
+    "@lens-protocol/metadata": "0.1.0-alpha.12",
     "@lens-protocol/shared-kernel": "workspace:*",
     "@lens-protocol/storage": "workspace:*",
     "@lit-protocol/constants": "2.1.62",

packages/gated-content/src/__tests__/paths.spec.ts

@@ -1,7 +1,7 @@
 import * as raw from '@lens-protocol/metadata';
 
 import * as gql from '../graphql';
-import { resolvePathsToDecrypt, resolvePathsToEncrypt } from '../paths';
+import { deriveDecryptionPaths, resolvePathsToDecrypt, resolvePathsToEncrypt } from '../paths';
 
 describe(`Given the paths helpers`, () => {
   describe(`when calling the "${resolvePathsToEncrypt.name}" function`, () => {
@@ -27,7 +27,6 @@ describe(`Given the paths helpers`, () => {
           'lens.content',
           // 'lens.title' // omitted on purpose to allow to tease potential audience
           'lens.audio.item',
-          'lens.audio.altTag',
           'lens.audio.cover',
           'lens.audio.credits',
           'lens.audio.artist',
@@ -202,24 +201,14 @@ describe(`Given the paths helpers`, () => {
       },
       {
         schema: raw.PublicationSchemaId.TEXT_ONLY_LATEST,
-        expected: [
-          'lens.content',
-          'lens.attachments[n].item',
-          'lens.attachments[n].altTag',
-          'lens.attachments[n].cover',
-          'lens.attachments[n].credits',
-          'lens.attachments[n].artist',
-          'lens.attachments[n].genre',
-          'lens.attachments[n].recordLabel',
-          'lens.attachments[n].lyrics',
-        ],
+        expected: ['lens.content'],
       },
       {
         schema: raw.PublicationSchemaId.THREE_D_LATEST,
         expected: [
           'lens.content',
-          'lens.threeDAssets[n].uri',
-          'lens.threeDAssets[n].playerUrl',
+          'lens.assets[n].uri',
+          'lens.assets[n].playerUrl',
           'lens.attachments[n].item',
           'lens.attachments[n].altTag',
           'lens.attachments[n].cover',

packages/gated-content/src/paths.ts

@@ -1,8 +1,20 @@
 import * as raw from '@lens-protocol/metadata';
+import { UnknownObject } from '@lens-protocol/shared-kernel';
 
 import * as gql from './graphql';
+import { Paths } from './types';
 
-const ToEncryptPaths: Record<raw.PublicationSchemaId, string[]> = {
+type MapOf<
+  Target extends UnknownObject,
+  Discriminant extends keyof Target = keyof Target,
+  DiscriminantValue extends string = Target[Discriminant] extends string
+    ? Target[Discriminant]
+    : never,
+> = {
+  [P in DiscriminantValue]: Paths<Extract<Target, { [KK in Discriminant]: P }>>[];
+};
+
+const ToEncryptPaths: MapOf<raw.PublicationMetadata, '$schema'> = {
   [raw.PublicationSchemaId.ARTICLE_LATEST]: [
     'lens.content',
     'lens.attachments[n].item',
@@ -17,7 +29,6 @@ const ToEncryptPaths: Record<raw.PublicationSchemaId, string[]> = {
   [raw.PublicationSchemaId.AUDIO_LATEST]: [
     'lens.content',
     'lens.audio.item',
-    'lens.audio.altTag',
     'lens.audio.cover',
     'lens.audio.credits',
     'lens.audio.artist',
@@ -163,22 +174,12 @@ const ToEncryptPaths: Record<raw.PublicationSchemaId, string[]> = {
     'lens.attachments[n].lyrics',
   ],
 
-  [raw.PublicationSchemaId.TEXT_ONLY_LATEST]: [
-    'lens.content',
-    'lens.attachments[n].item',
-    'lens.attachments[n].altTag',
-    'lens.attachments[n].cover',
-    'lens.attachments[n].credits',
-    'lens.attachments[n].artist',
-    'lens.attachments[n].genre',
-    'lens.attachments[n].recordLabel',
-    'lens.attachments[n].lyrics',
-  ],
+  [raw.PublicationSchemaId.TEXT_ONLY_LATEST]: ['lens.content'],
 
   [raw.PublicationSchemaId.THREE_D_LATEST]: [
     'lens.content',
-    'lens.threeDAssets[n].uri',
-    'lens.threeDAssets[n].playerUrl',
+    'lens.assets[n].uri',
+    'lens.assets[n].playerUrl',
     'lens.attachments[n].item',
     'lens.attachments[n].altTag',
     'lens.attachments[n].cover',
@@ -218,7 +219,9 @@ const ToEncryptPaths: Record<raw.PublicationSchemaId, string[]> = {
   ],
 };
 
-export function resolvePathsToEncrypt({ $schema }: raw.PublicationMetadata): string[] {
+export function resolvePathsToEncrypt<T extends raw.PublicationMetadata>({
+  $schema,
+}: T): Paths<raw.PublicationMetadata>[] {
   if ($schema in ToEncryptPaths) {
     return ToEncryptPaths[$schema];
   }
@@ -534,3 +537,7 @@ export function resolvePathsToDecrypt({ __typename }: gql.AnyEncryptedPublicatio
   // decrypt it.
   return [];
 }
+
+export function deriveDecryptionPaths(paths: string[]): string[] {
+  return paths;
+}

packages/gated-content/src/types.ts

@@ -1,4 +1,5 @@
 import { UnknownObject } from '@lens-protocol/shared-kernel';
+import { Primitive } from 'zod';
 
 import { Maybe } from './graphql';
 
@@ -15,3 +16,18 @@ export type Entries<T> = Values<KeyValuePairs<T>>;
 export type ExtractFields<T extends UnknownObject, F extends string> = Pick<T, Extract<keyof T, F>>;
 
 export type Mutable<T> = { -readonly [P in keyof T]: T[P] };
+
+type UnionOf<A> = A extends Array<unknown> ? A[number] : A[keyof A];
+
+// Adapted from ts-toolbelt: https://github.com/millsp/ts-toolbelt/blob/master/sources/Object/Paths.ts#L21
+export type Paths<Target, Root extends string = ''> = UnionOf<{
+  [K in keyof Target]: K extends string
+    ? `${Root}${Target[K] extends Primitive | undefined
+        ? K
+        : Target[K] extends Array<infer ItemType> | undefined
+        ? ItemType extends Primitive // acts also to distribute over union ItemType
+          ? `${K}[n]`
+          : Paths<ItemType, `${K}[n].`>
+        : Paths<Target[K], `${K}.`>}`
+    : never;
+}>;