Add tests to see all pattern uses are the same

scripts/build/pattern.js

@@ -7,9 +7,7 @@ const pattern = new RegExp(
 	patterns
 		.map((pattern) => pattern.replace(/[.*+?^${}()|[\]\\]/g, "\\$&"))
 		.join("|"),
-)
-	.toString()
-	.slice(1, -1);
+).source;
 
 const expression = new RegExp(patterns.join("|"), "i").toString();
 

src/index.ts

@@ -31,6 +31,7 @@ let usedPattern: RegExp;
 export function isbot(userAgent?: string | null): boolean {
 	if (typeof usedPattern === "undefined") {
 		try {
+			// Build this RegExp dynamically to avoid syntax errors in older engines.
 			usedPattern = new RegExp(fullPattern, "i");
 		} catch (error) {
 			usedPattern = naivePattern;

tests/spec/test.ts

@@ -10,6 +10,7 @@ import {
 	createIsbot,
 	createIsbotFromList,
 } from "../../src";
+import { fullPattern, regularExpression } from "../../src/pattern";
 import { crawlers, browsers } from "../../fixtures";
 let isbotInstance: any;
 
@@ -131,7 +132,7 @@ describe("isbot", () => {
 		afterAll(() => {
 			jest.restoreAllMocks();
 		});
-		test("Fallback regex detects commong crawlers", () => {
+		test("fallback regex detects commong crawlers", () => {
 			USER_AGENT_COMMON.forEach((ua) => {
 				if (!isbotInstance(ua)) {
 					throw new Error(`Failed to detect ${ua} as bot`);
@@ -186,5 +187,9 @@ describe("isbot", () => {
 			);
 			expect(types).toMatchSnapshot();
 		});
+		test("regular expressions exports are as expected", () => {
+			expect(pattern).toBe(regularExpression);
+			expect(new RegExp(fullPattern, "i").toString()).toBe(pattern.toString());
+		});
 	});
 });