fix: incorrect error message for browser UMD bundle

src/util/error.ts

@@ -7,18 +7,16 @@ export abstract class LiquidError extends Error {
   public context = ''
   private originalError?: Error
   public constructor (err: Error | string, token: Token) {
+    /**
+     * note: for ES5 targeting, `this` will be replaced by return value of Error(),
+     * thus everything on `this` will be lost, avoid calling `LiquidError` methods here
+     */
     super(typeof err === 'string' ? err : err.message)
-    if (typeof err !== 'string') this.defineUnEnumerable('originalError', err)
-    this.defineUnEnumerable('token', token)
-  }
-  private defineUnEnumerable (property: string, value: unknown) {
-    Object.defineProperty(this, property, {
-      value: value,
-      enumerable: false
-    })
+    if (typeof err !== 'string') Object.defineProperty(this, 'originalError', { value: err, enumerable: false })
+    Object.defineProperty(this, 'token', { value: token, enumerable: false })
   }
   protected update () {
-    this.defineUnEnumerable('context', mkContext(this.token))
+    Object.defineProperty(this, 'context', { value: mkContext(this.token), enumerable: false })
     this.message = mkMessage(this.message, this.token)
     this.stack = this.message + '\n' + this.context +
       '\n' + this.stack

test/e2e/browser.spec.ts

@@ -0,0 +1,10 @@
+const LiquidUMD = require('../../dist/liquid.browser.umd.js').Liquid
+
+describe('browser', function () {
+  it('should yield unclosed output error', () => {
+    const engine = new LiquidUMD()
+    return expect(engine.parseAndRender('{{huh')).rejects.toMatchObject({
+      message: 'output "{{huh" not closed, line:1, col:1'
+    })
+  })
+})