Fix toString DDGProxy response (#324)

* Fix toString DDGProxy response

Author: jonathanKingston

integration-test/test-utils.js

@@ -0,0 +1,36 @@
+/**
+ *  Tests for utils
+ */
+import { setup } from './helpers/harness.js'
+
+describe('Ensure utils behave as expected', () => {
+    let browser
+    let server
+    let teardown
+    let setupServer
+    let gotoAndWait
+    beforeAll(async () => {
+        ({ browser, setupServer, teardown, gotoAndWait } = await setup({ withExtension: true }))
+        server = setupServer()
+    })
+    afterAll(async () => {
+        await server?.close()
+        await teardown()
+    })
+
+    it('should toString DDGProxy correctly', async () => {
+        const port = server.address().port
+        const page = await browser.newPage()
+        await gotoAndWait(page, `http://localhost:${port}/blank.html`, { platform: { name: 'extension' } })
+        const toStringResult = await page.evaluate('HTMLCanvasElement.prototype.getContext.toString()')
+        expect(toStringResult).toEqual('function getContext() { [native code] }')
+
+        const toStringToStringResult = await page.evaluate('HTMLCanvasElement.prototype.getContext.toString.toString()')
+        expect(toStringToStringResult).toEqual('function toString() { [native code] }')
+
+        /* TOFIX: This is failing because the toString() call is being proxied and the result is not what we expect
+        const callToStringToStringResult = await page.evaluate('String.toString.call(HTMLCanvasElement.prototype.getContext.toString)')
+        expect(callToStringToStringResult).toEqual('function toString() { [native code] }')
+        */
+    })
+})

src/utils.js

@@ -377,16 +377,29 @@ export class DDGProxy {
             }
             return proxyObject.apply(...args)
         }
+        const getMethod = (target, prop, receiver) => {
+            if (prop === 'toString') {
+                const method = Reflect.get(target, prop, receiver).bind(target)
+                Object.defineProperty(method, 'toString', {
+                    value: String.toString.bind(String.toString),
+                    enumerable: false
+                })
+                return method
+            }
+            return DDGReflect.get(target, prop, receiver)
+        }
         if (hasMozProxies) {
             this._native = objectScope[property]
             const handler = new globalObj.wrappedJSObject.Object()
             handler.apply = exportFunction(outputHandler, globalObj)
+            handler.get = exportFunction(getMethod, globalObj)
             // @ts-ignore
             this.internal = new globalObj.wrappedJSObject.Proxy(objectScope.wrappedJSObject[property], handler)
         } else {
             this._native = objectScope[property]
             const handler = {}
             handler.apply = outputHandler
+            handler.get = getMethod
             this.internal = new globalObj.Proxy(objectScope[property], handler)
         }
     }