convert sequenceDb to class.

packages/mermaid/src/diagrams/sequence/sequenceDiagram.spec.js

@@ -3,6 +3,7 @@ import { setSiteConfig } from '../../diagram-api/diagramAPI.js';
 import mermaidAPI from '../../mermaidAPI.js';
 import { Diagram } from '../../Diagram.js';
 import { addDiagrams } from '../../diagram-api/diagram-orchestration.js';
+import { SequenceDB } from './sequenceDb.js';
 
 beforeAll(async () => {
   // Is required to load the sequence diagram
@@ -97,8 +98,8 @@ let diagram;
 describe('more than one sequence diagram', () => {
   it('should not have duplicated messages', async () => {
     const diagram1 = await Diagram.fromText(`
-        sequenceDiagram
-        Alice->Bob:Hello Bob, how are you?
+         sequenceDiagram
+         Alice->Bob:Hello Bob, how are you?
         Bob-->Alice: I am good thanks!`);
     expect(diagram1.db.getMessages()).toMatchInlineSnapshot(`
       [
@@ -2071,3 +2072,27 @@ ${prop}-->>A: Hello, how are you?`)
     ).resolves.toBeDefined();
   });
 });
+
+describe('sequence db class', () => {
+  let sequenceDb;
+  beforeEach(() => {
+    sequenceDb = new SequenceDB();
+  });
+  // This is to ensure that functions used in sequence JISON are exposed as function from SequenceDB
+  it('should have functions used in sequence JISON as own property', () => {
+    const functionsUsedInParser = [
+      'apply',
+      'parseBoxData',
+      'LINETYPE',
+      'setDiagramTitle',
+      'setAccTitle',
+      'setAccDescription',
+      'parseMessage',
+      'PLACEMENT',
+    ];
+
+    for (const fun of functionsUsedInParser) {
+      expect(Object.hasOwn(sequenceDb, fun)).toBe(true);
+    }
+  });
+});

packages/mermaid/src/diagrams/sequence/sequenceDiagram.ts

@@ -1,13 +1,20 @@
 import type { DiagramDefinition } from '../../diagram-api/types.js';
 // @ts-ignore: JISON doesn't support types
 import parser from './parser/sequenceDiagram.jison';
-import db from './sequenceDb.js';
+import { SequenceDB } from './sequenceDb.js';
 import styles from './styles.js';
 import renderer from './sequenceRenderer.js';
 
+let db: SequenceDB;
+
 export const diagram: DiagramDefinition = {
   parser,
-  db,
+  get db() {
+    if (!db) {
+      db = new SequenceDB();
+    }
+    return db;
+  },
   renderer,
   styles,
   init: ({ wrap }) => {