Implemented patch for TextMode

src/TextMode.js

@@ -1,5 +1,6 @@
 import { h, Component } from 'preact'
 import { parseJSON } from './utils/jsonUtils'
+import { jsonToData, dataToJson, patchData } from './jsonData'
 
 export default class TextMode extends Component {
   // TODO: define propTypes
@@ -109,11 +110,23 @@ export default class TextMode extends Component {
   /**
    * Apply a JSONPatch to the current JSON document
    * @param {JSONPatch} actions   JSONPatch actions
-   * @return {JSONPatch} Returns a JSONPatch to revert the applied patch
+   * @return {JSONPatchResult} Returns a JSONPatch result containing the
+   *                           patch, a patch to revert the action, and
+   *                           an error object which is null when successful
    */
   patch (actions) {
-    // TODO: implement patch
-    throw new Error('Patch not yet implemented')
+    const json = this.get()
+
+    const data = jsonToData(json)
+    const result = patchData(data, actions)
+
+    this.set(dataToJson(result.data))
+
+    return {
+      patch: actions,
+      revert: result.revert,
+      error: result.error
+    }
   }
 
   /**

src/TreeMode.js

@@ -236,7 +236,9 @@ export default class TreeMode extends Component {
   /**
    * Apply a JSONPatch to the current JSON document
    * @param {JSONPatch} actions   JSONPatch actions
-   * @return {JSONPatch} Returns a JSONPatch to revert the applied patch
+   * @return {JSONPatchResult} Returns a JSONPatch result containing the
+   *                           patch, a patch to revert the action, and
+   *                           an error object which is null when successful
    */
   patch (actions) {
     const result = patchData(this.state.data, actions)
@@ -256,7 +258,11 @@ export default class TreeMode extends Component {
       historyIndex: 0
     })
 
-    return result.revert
+    return {
+      patch: actions,
+      revert: result.revert,
+      error: result.error
+    }
   }
 
   /**

src/jsonData.js

@@ -90,7 +90,7 @@ export function toDataPath (data, path) {
     const index = path[0]
     const item = data.items[index]
     if (!item) {
-      throw new Error('Array item ' + index + ' not found')
+      throw new Error('Array item "' + index + '" not found')
     }
 
     return ['items', index].concat(toDataPath(item, path.slice(1)))

src/typedef.js

@@ -25,6 +25,12 @@
  * @typedef {Array.<{op: string, path?: string, from?: string, value?: *}>} JSONPatch
  *
  * @typedef {{
+ *   patch: JSONPatch,
+ *   revert: JSONPatch,
+ *   error: null | Error
+ * }} JSONPatchResult
+ *
+ * @typedef {{
  *   mode: 'tree' | 'text',
  *   indentation: number | string,
  *   onChange: function (patch: JSONPatch, revert: JSONPatch),