add config unit test cases for pie chart

packages/mermaid/src/diagrams/pie/pie.spec.ts

@@ -1,6 +1,6 @@
 // @ts-ignore - jison doesn't export types
 import { parser } from './parser/pie.jison';
-import { db } from './pieDb.js';
+import { DEFAULT_PIE_DB, db } from './pieDb.js';
 import { setConfig } from '../../config.js';
 
 setConfig({
@@ -10,9 +10,11 @@ setConfig({
 describe('pie chart', () => {
   beforeEach(() => {
     parser.yy = db;
-    parser.yy.clear();
+    db.clear();
+    db.reset();
   });
 
+  describe('parse', () => {
     it('should handle very simple pie', () => {
       parser.parse(`pie
       "ash": 100
@@ -145,4 +147,23 @@ describe('pie chart', () => {
         `);
       }).toThrowError();
     });
+  });
+
+  describe('config', () => {
+    it('setConfig', () => {
+      db.setConfig({ useWidth: 850, useMaxWidth: undefined });
+      expect(db.getConfig().useWidth).toBe(850);
+      expect(db.getConfig().useMaxWidth).toBeTruthy();
+    });
+
+    it('getConfig', () => {
+      expect(db.getConfig()).toStrictEqual(DEFAULT_PIE_DB.config);
+    });
+
+    it('reset', () => {
+      db.setConfig({ useWidth: 850 });
+      db.reset();
+      expect(db.getConfig().useWidth).toStrictEqual(DEFAULT_PIE_DB.config.useWidth);
+    });
+  });
 });