Feature/math improve (#2976)

* add new feature

* add test file

* update test file

* update test file

* Fix linting

---------

Co-authored-by: Dolan Miu <dolan_miu@hotmail.com>

src/file/paragraph/math/bar/math-bar-properties.spec.ts

@@ -0,0 +1,43 @@
+import { describe, expect, it } from "vitest";
+
+import { Formatter } from "@export/formatter";
+
+import { MathBarProperties } from "./math-bar-properties";
+describe("MathBarProperties", () => {
+    describe("#constructor()", () => {
+        it("should create a MathBarProperties with top key", () => {
+            const mathBarProperties = new MathBarProperties("top");
+
+            const tree = new Formatter().format(mathBarProperties);
+
+            expect(tree).to.deep.equal({
+                "m:barPr": [
+                    {
+                        "m:pos": {
+                            _attr: {
+                                "w:val": "top",
+                            },
+                        },
+                    },
+                ],
+            });
+        });
+        it("should create a MathBarProperties with bottom key", () => {
+            const mathBarProperties = new MathBarProperties("bot");
+
+            const tree = new Formatter().format(mathBarProperties);
+
+            expect(tree).to.deep.equal({
+                "m:barPr": [
+                    {
+                        "m:pos": {
+                            _attr: {
+                                "w:val": "bot",
+                            },
+                        },
+                    },
+                ],
+            });
+        });
+    });
+});