Make the source argument for setDataAtCell in the Merge Cells plugin more specific.

.changelogs/10857.json

@@ -0,0 +1,8 @@
+{
+  "issuesOrigin": "private",
+  "title": "Unified the `source` arguments of the `beforeChange`/`afterChange` hooks when being triggered by the Merge Cells plugin.",
+  "type": "fixed",
+  "issueOrPR": 10857,
+  "breaking": false,
+  "framework": "none"
+}

docs/content/guides/getting-started/events-and-hooks/events-and-hooks.md

@@ -170,7 +170,7 @@ It's worth mentioning that some Handsontable hooks are triggered from the Handso
 | [`ContextMenu.rowAbove`](@/api/contextMenu.md)     | Action triggered by the ContextMenu plugin after the "Insert row above" has been clicked.                                                                                                                              |
 | [`ContextMenu.rowBelow`](@/api/contextMenu.md)     | Action triggered by the ContextMenu plugin after the "Insert row below" has been clicked.                                                                                                                              |
 | [`CopyPaste.paste`](@/api/copyPaste.md)            | Action triggered by the CopyPaste plugin after the value has been pasted.                                                                                                                                              |
-| `ObserveChanges.change`                            | Action triggered by the ObserveChanges plugin after the changes have been detected.                                                                                                                                    |
+| `MergeCells`                            | Action triggered by the MergeCells plugin when clearing the merged cells' underlying cells. |
 | [`UndoRedo.redo`](@/api/undoRedo.md)               | Action triggered by the UndoRedo plugin after the change has been redone.                                                                                                                                              |
 | [`UndoRedo.undo`](@/api/undoRedo.md)               | Action triggered by the UndoRedo plugin after the change has been undone.                                                                                                                                              |
 | [`ColumnSummary.set`](@/api/columnSummary.md)      | Action triggered by the ColumnSummary plugin after the calculation has been done.                                                                                                                                      |

handsontable/src/plugins/mergeCells/__tests__/mergeCells.spec.js

@@ -67,6 +67,36 @@ describe('MergeCells', () => {
       ]);
     });
 
+    it('should provide information about the source of the change in the `beforeChange` and `afterChange` hooks', () => {
+      const beforeChange = jasmine.createSpy('beforeChange');
+      const afterChange = jasmine.createSpy('afterChange');
+
+      handsontable({
+        data: [
+          [1, 2, 3, 4],
+          [5, 6, 7, 8],
+          [9, 10, 11, 12],
+          [13, 14, 15, 16],
+        ],
+        mergeCells: [{
+          row: 0,
+          col: 0,
+          rowspan: 2,
+          colspan: 2
+        }],
+        beforeChange,
+        afterChange,
+      });
+
+      expect(beforeChange.calls.mostRecent().args[1]).toEqual('MergeCells');
+      expect(afterChange.calls.mostRecent().args[1]).toEqual('MergeCells');
+
+      getPlugin('mergeCells').merge(2, 2, 3, 3);
+
+      expect(beforeChange.calls.mostRecent().args[1]).toEqual('MergeCells');
+      expect(afterChange.calls.mostRecent().args[1]).toEqual('MergeCells');
+    });
+
     it('should merge cells on startup respecting indexes sequence changes', () => {
       handsontable({
         data: [

handsontable/src/plugins/mergeCells/mergeCells.js

@@ -313,7 +313,8 @@ export class MergeCells extends BasePlugin {
         return;
       }
 
-      this.hot.setDataAtCell(populatedNulls);
+      // TODO: Change the `source` argument to a more meaningful value, e.g. `${this.pluginName}.clearCells`.
+      this.hot.setDataAtCell(populatedNulls, undefined, undefined, this.pluginName);
     }
   }
 
@@ -451,6 +452,7 @@ export class MergeCells extends BasePlugin {
         populationInfo = [mergeParent.row, mergeParent.col, clearedData];
 
       } else {
+        // TODO: Change the `source` argument to a more meaningful value, e.g. `${this.pluginName}.clearCells`.
         this.hot.populateFromArray(
           mergeParent.row, mergeParent.col, clearedData, undefined, undefined, this.pluginName);
       }