Fix types

Author: janicduplessis

lib/index.d.ts

@@ -1,6 +1,6 @@
 import Onyx, {OnyxUpdate, ConnectOptions} from './Onyx';
-import {CustomTypeOptions, OnyxCollection, OnyxEntry} from './types';
+import {CustomTypeOptions, OnyxCollection, OnyxEntry, ComputedKey} from './types';
 import withOnyx from './withOnyx';
 
 export default Onyx;
-export {CustomTypeOptions, OnyxCollection, OnyxEntry, OnyxUpdate, withOnyx, ConnectOptions};
+export {CustomTypeOptions, OnyxCollection, OnyxEntry, OnyxUpdate, withOnyx, ConnectOptions, ComputedKey};

lib/types.d.ts

@@ -99,6 +99,26 @@ type CollectionKey = `${CollectionKeyBase}${string}`;
  */
 type OnyxKey = Key | CollectionKey;
 
+/**
+ * A computed key is a key that is not stored in the database, but instead is computed from other keys
+ * and cached in memory. This is useful for expensive computations that are used in multiple places.
+ */
+type ComputedKey<DependenciesT, ValueT> = {
+    /**
+     * The cache key of the computed value.
+     */
+    cacheKey: string;
+    /**
+     * Keys that this computed key depends on. The values of these keys will be passed to the compute function.
+     * This will also cause the key to be recomputed whenever any of the dependencies value change.
+     */
+    dependencies?: {[KeyT in keyof DependenciesT]: OnyxKey | ComputedKey<any, unknown>};
+    /**
+     * Compute the value for this computed key.
+     */
+    compute: (params: DependenciesT) => ValueT;
+};
+
 /**
  * Represents a mapping of Onyx keys to values, where keys are either normal or collection Onyx keys
  * and values are the corresponding values in Onyx's state.
@@ -226,4 +246,4 @@ type NullishObjectDeep<ObjectType extends object> = {
  */
 type WithOnyxInstanceState<TOnyxProps> = (TOnyxProps & {loading: boolean}) | undefined;
 
-export {CollectionKey, CollectionKeyBase, CustomTypeOptions, DeepRecord, Key, KeyValueMapping, OnyxCollection, OnyxEntry, OnyxKey, Selector, NullishDeep, WithOnyxInstanceState};
+export {CollectionKey, CollectionKeyBase, ComputedKey, CustomTypeOptions, DeepRecord, Key, KeyValueMapping, OnyxCollection, OnyxEntry, OnyxKey, Selector, NullishDeep, WithOnyxInstanceState};

lib/withOnyx.d.ts

@@ -1,5 +1,5 @@
 import {IsEqual} from 'type-fest';
-import {CollectionKeyBase, KeyValueMapping, OnyxCollection, OnyxEntry, OnyxKey, Selector} from './types';
+import {CollectionKeyBase, ComputedKey, KeyValueMapping, OnyxCollection, OnyxEntry, OnyxKey, Selector} from './types';
 
 /**
  * Represents the base mapping options between an Onyx key and the component's prop.
@@ -86,6 +86,25 @@ type BaseMappingFunctionKeyAndSelector<TComponentProps, TOnyxProps, TOnyxProp ex
     selector: Selector<TOnyxKey, TOnyxProps, TOnyxProps[TOnyxProp]>;
 };
 
+/**
+ * TODO
+ *
+ * @example
+ * ```ts
+ * // Onyx prop with computed key.
+ * accountName: {
+ *     key: {
+ *         cacheKey: ONYXKEYS.COMPUTED.ACCOUNT_NAME,
+ *         dependencies: {account: ONYXKEYS.ACCOUNT},
+ *         compute: ({account}) => account.name,
+ *     },
+ * },
+ * ```
+ */
+type BaseMappingComputedKey<TComponentProps, TOnyxProps, TOnyxProp extends keyof TOnyxProps> = {
+    key: ComputedKey<any, TOnyxProps[TOnyxProp]> | ((props: Omit<TComponentProps, keyof TOnyxProps> & Partial<TOnyxProps>) => ComputedKey<any, TOnyxProps[TOnyxProp]>);
+};
+
 /**
  * Represents the mapping options between an Onyx key and the component's prop with all its possibilities.
  */
@@ -95,6 +114,7 @@ type Mapping<TComponentProps, TOnyxProps, TOnyxProp extends keyof TOnyxProps, TO
         | BaseMappingKey<TComponentProps, TOnyxProps, TOnyxProp, TOnyxKey, OnyxEntry<KeyValueMapping[TOnyxKey]>>
         | BaseMappingStringKeyAndSelector<TComponentProps, TOnyxProps, TOnyxProp, TOnyxKey>
         | BaseMappingFunctionKeyAndSelector<TComponentProps, TOnyxProps, TOnyxProp, TOnyxKey>
+        | BaseMappingComputedKey<TComponentProps, TOnyxProps, TOnyxProp>
     );
 
 /**
@@ -106,6 +126,7 @@ type CollectionMapping<TComponentProps, TOnyxProps, TOnyxProp extends keyof TOny
         | BaseMappingKey<TComponentProps, TOnyxProps, TOnyxProp, TOnyxKey, OnyxCollection<KeyValueMapping[TOnyxKey]>>
         | BaseMappingStringKeyAndSelector<TComponentProps, TOnyxProps, TOnyxProp, TOnyxKey>
         | BaseMappingFunctionKeyAndSelector<TComponentProps, TOnyxProps, TOnyxProp, TOnyxKey>
+        | BaseMappingComputedKey<TComponentProps, TOnyxProps, TOnyxProp>
     );
 
 /**