Allow onUpdate functions to return true to represent success

Author: CarlosNZ

README.md

@@ -165,9 +165,8 @@ The function will receive the following object as a parameter:
                   // (e.g. [ "user", "friends", 1, "name" ] ) (equivalent to "user.friends[1].name")
 }
 ```
-
-The function needn't return anything, in which case the data is updated normally. However, you can return either an Error value, or a modified data value, which will be used instead of the input data. The return value can be one of the following:
-- `void` / `undefined`: data continues update as normal
+The function can return nothing (in which case the data is updated normally), or a value to represent success/failure, error value, or modified data. The return value can be one of the following, and handled accordingly:
+- `true` / `void` / `undefined`: data continues update as normal
 - `false`: considers the update to be an error, so data is not updated (reverts to previous value), and a generic error message is displayed in the UI
 - `string`: also considered an error, so no data update, but the UI error message will be your provided string
 - `[ "value", <value> ]`: tells the component to use the returned `<value>` instead of the input data. You might use this to automatically modify user input -- for example, sorting an array, or inserting a timestamp field into an object.

demo/src/demoData/dataDefinitions.tsx

@@ -45,7 +45,7 @@ export interface DemoData {
   onUpdate?: (
     props: UpdateFunctionProps,
     toast: (options: unknown) => void
-  ) => void | ErrorString | false | Promise<false | ErrorString | void>
+  ) => void | ErrorString | boolean | Promise<boolean | ErrorString | void>
   onAdd?: UpdateFunction
   onEdit?: UpdateFunction
   onChange?: OnChangeFunction

src/JsonEditor.tsx

@@ -103,7 +103,7 @@ const Editor: React.FC<JsonEditorProps> = ({
   const handleEdit = async (updateMethod: UpdateFunction, input: UpdateFunctionProps) => {
     const result = await updateMethod(input)
 
-    if (result === undefined) {
+    if (result === true || result === undefined) {
       setData(input.newData)
       return
     }
@@ -373,7 +373,7 @@ const getSearchFilter = (
 }
 
 const isUpdateReturnTuple = (
-  input: UpdateFunctionReturn | string | false | undefined
+  input: UpdateFunctionReturn | string | boolean | undefined
 ): input is UpdateFunctionReturn => {
   return Array.isArray(input) && input.length === 2 && ['error', 'value'].includes(input[0])
 }

src/types.ts

@@ -90,9 +90,9 @@ export type UpdateFunction = (
 ) =>
   | void
   | ErrorString
-  | false
+  | boolean
   | UpdateFunctionReturn
-  | Promise<false | ErrorString | void | UpdateFunctionReturn>
+  | Promise<boolean | ErrorString | void | UpdateFunctionReturn>
 
 export type OnChangeFunction = (props: {
   currentData: JsonData