feat(lib/assets): add api for registering custom and overriding assets

lib/assets/src/index.ts

@@ -5,9 +5,16 @@ import { AssetRegistry } from './patches'
 
 import type { ReactNative as RN } from '@revenge-mod/types'
 
-export type Asset = RN.AssetsRegistry.PackagerAsset
+export type Asset = ReactNativeAsset | RevengeAsset
 export type AssetId = number
 
+export type ReactNativeAsset = RN.AssetsRegistry.PackagerAsset
+export interface RevengeAsset extends Pick<ReactNativeAsset, 'name' | 'width' | 'height' | 'type'> {
+    uri: string
+}
+
+export type RegisterableAsset = Omit<RevengeAsset, 'id'>
+
 // iOS cannot display SVGs
 let _preferredType: Asset['type'] = ReactNative.Platform.OS === 'ios' ? 'png' : 'svg'
 
@@ -60,3 +67,33 @@ export function getAssetsByName(name: string): Record<Asset['type'], Asset> | un
 export function setPreferredAssetType(type: Asset['type']) {
     _preferredType = type
 }
+
+/**
+ * Register an asset with the given name.
+ * If an asset with the same name already exists, it will be overridden if `override` is set to true.
+ *
+ * @param asset The asset to register.
+ * @param override Whether to override the existing asset if one exists. `false` by default.
+ * @throws An error if an asset with the same name and type already exists and `override` is not set to true.
+ */
+export function registerAsset(asset: RegisterableAsset, override?: boolean) {
+    const { name } = asset
+
+    if (override) _overrides.set(name, asset)
+    // Make sure to not override the asset if it already exists, unless explicitly set to override
+    else if (_assets.get(name)?.[1]?.[asset.type])
+        throw new Error(`Asset "${name}" with type "${asset.type}" already exists`)
+
+    // @ts-expect-error
+    return AssetRegistry.registerAsset(asset)
+}
+
+/**
+ * Remove an asset override.
+ *
+ * @param name The name of the asset to remove the override for.
+ * @returns Whether the override was removed.
+ */
+export function removeAssetOverride(name: string) {
+    return _overrides.delete(name)
+}

lib/assets/src/patches.ts

@@ -1,15 +1,17 @@
 import { _mUninited } from '@revenge-mod/modules/_/metro'
 import { waitForModules } from '@revenge-mod/modules/finders'
-import { byProps } from '@revenge-mod/modules/finders/filters'
+import { byName, byProps } from '@revenge-mod/modules/finders/filters'
 import { getModuleDependencies } from '@revenge-mod/modules/metro'
 
-import { _assets, _ids } from './_internal'
+import { _assets, _ids, _overrides } from './_internal'
 
 import type { ReactNative } from '@revenge-mod/types'
-import type { Asset } from '.'
+import type { Asset, ReactNativeAsset } from '.'
 
 export let AssetRegistry: ReactNative.AssetsRegistry
+export let AssetRegistryModuleId: number
 
+// Tracking/caching assets
 const unsubForAssetRegistry = waitForModules(byProps('registerAsset'), (arId, exports) => {
     // We want to do caching only for the re-exported asset-registry
     if (!getModuleDependencies(arId)!.length) {
@@ -33,6 +35,7 @@ const unsubForAssetRegistry = waitForModules(byProps('registerAsset'), (arId, ex
     }
 
     unsubForAssetRegistry()
+    AssetRegistryModuleId = arId
 
     // TODO(assets/patches): conditionally run this if cache does not exist
     // More fragile way, but more performant:
@@ -45,3 +48,16 @@ const unsubForAssetRegistry = waitForModules(byProps('registerAsset'), (arId, ex
         if (deps.length === 1 && deps[0] === arId) __r(id)
     }
 })
+
+// Asset overrides
+const unsubForResolveAssetSource = waitForModules(
+    byName<{
+        addCustomSourceTransformer: (transformer: (arg: { asset: Asset }) => ReactNativeAsset) => void
+    }>('resolveAssetSource'),
+    (_, resolveAssetSource) => {
+        unsubForResolveAssetSource()
+
+        // @ts-expect-error
+        resolveAssetSource.addCustomSourceTransformer(({ asset }) => _overrides.get(asset.name))
+    },
+)