add removeNote func

Author: CTyrannosaurus

README.md

@@ -1258,6 +1258,9 @@ ws.getCell('B1').note = {
   },
   editAs: 'twoCells',
 };
+
+// remove note
+ws.getCell('B1').removeNote()
 ```
 
 ### Cell Comments Properties[⬆](#contents)<!-- Link generated with jump2header -->

README_zh.md

@@ -1204,6 +1204,9 @@ ws.getCell('B1').note = {
   },
   editAs: 'twoCells'
 };
+
+// 移除单元格注释
+ws.getCell('B1').removeNote()
 ```
 
 ### 单元格批注属性[⬆](#目录)<!-- Link generated with jump2header -->

index.d.ts

@@ -504,6 +504,11 @@ export interface Cell extends Style, Address {
 	unmerge(): void;
 	isMergedTo(master: Cell): boolean;
 	toString(): string;
+
+	/**
+	 * Remove comment of the cell
+	 */
+	removeNote(): void;
 }
 
 export interface RowModel {

lib/doc/cell.js

@@ -229,6 +229,10 @@ class Cell {
     this._comment = new Note(note);
   }
 
+  removeNote() {
+    delete this._comment;
+  }
+
   get text() {
     return this._value.toString();
   }
@@ -331,6 +335,8 @@ class Cell {
     model.style = this.style;
     if (this._comment) {
       model.comment = this._comment.model;
+    } else {
+      delete model.comment;
     }
     return model;
   }

spec/unit/doc/cell.spec.js

@@ -369,6 +369,28 @@ describe('Cell', () => {
     expect(a1.model.comment.note).to.deep.equal(comment);
   });
 
+  it('can remove comment', () => {
+    const a1 = sheetMock.getCell('A1');
+
+    expect(a1.note).to.be.undefined();
+
+    a1.note = 'Some note';
+    expect(a1.model.comment.note.texts[0].text).to.be.eq('Some note');
+
+    a1.removeNote();
+    expect(a1.model.comment).to.be.undefined();
+  });
+
+  it('fails to remove comment by assigning empty object', () => {
+    const a1 = sheetMock.getCell('A1');
+    a1.note = 'Some note';
+
+    expect(a1.model.comment.note.texts[0].text).to.be.eq('Some note');
+
+    a1.note = {};
+    expect(a1.model.comment).to.exist();
+  });
+
   it('Cell comments supports setting margins, protection, and position properties', () => {
     const a1 = sheetMock.getCell('A1');
 
@@ -399,10 +421,7 @@ describe('Cell', () => {
     expect(a1.model.comment.note.protection).to.deep.equal(comment.protection);
     expect(a1.model.comment.note.margins.insetmode).to.equal('auto');
     expect(a1.model.comment.note.margins.inset).to.deep.equal([
-      0.13,
-      0.13,
-      0.25,
-      0.25,
+      0.13, 0.13, 0.25, 0.25,
     ]);
     expect(a1.model.comment.note.editAs).to.equal('absolute');
   });