fix(generator): Prevent possible inifinite loop when tab isn't visible

Add bulletproof code, when tab isn't visible terminate the loop.

Ref naver#2606

src/module/generator.ts

@@ -4,7 +4,7 @@
  */
 import {d3Transition} from "../../types/types";
 import {window} from "./browser";
-import {isArray} from "./util";
+import {isArray, isTabVisible} from "./util";
 
 const {setTimeout, clearTimeout} = window;
 
@@ -66,6 +66,12 @@ export function generateWait() {
 					continue;
 				}
 
+				// when tab isn't visible exit loop
+				if (isTabVisible() === false) {
+					done = transitionsToWait.length;
+					break;
+				}
+
 				try {
 					t.transition();
 				} catch (e) {

src/module/util.ts

@@ -721,7 +721,7 @@ function parseDate(date: Date | string | number | any): Date {
  * @private
  */
 function isTabVisible(): boolean {
-	return !document.hidden;
+	return document?.hidden === false || document?.visibilityState === "visible";
 }
 
 /**

test/internals/generator-spec.ts

@@ -0,0 +1,52 @@
+/**
+ * Copyright (c) 2017 ~ present NAVER Corp.
+ * billboard.js project is licensed under the MIT license
+ */
+/* eslint-disable */
+import {expect} from "chai";
+import sinon from "sinon";
+import util from "../assets/util";
+import {window} from "../../src/module/browser";
+import {isTabVisible} from "../../src/module/util";
+
+describe("GENERATOR", function() {
+	let chart;
+	let args;
+
+	beforeEach(() => {
+		chart = util.generate(args);
+	});
+
+	describe("generateWait()", () => {
+		const spy = sinon.spy();
+
+		before(() => {
+			args = {
+				data: {
+					columns: [
+						["data1", 30, 200, 100, 400, 150, 250],
+						["data2", 50, 20, 10, 40, 15, 25],
+						["data3", 150, 120, 110, 140, 115, 125]
+					]
+				},
+				onrendered: spy
+			};
+		});
+
+		it("should onrendered callback called, when tab isn't visible", done => {
+			window.$$TEST$$.isTabVisible = false;
+
+			// when
+			chart.toggle(["data1", "data2"]);
+
+			setTimeout(() => {
+				expect(isTabVisible()).to.be.false;
+				expect(spy.called).to.be.true;
+
+				// restore
+				delete window.$$TEST$$.isTabVisible;
+				done();
+			}, 500);
+		});
+	});
+});