Add test:playwright:open-browser script

Lets you open a headed browser which is configured to use the
interception proxy. Useful for local debugging of browser tests.

package.json

@@ -132,6 +132,7 @@
     "test:node:skip-build": "mocha",
     "test:webserver": "grunt test:webserver",
     "test:playwright": "node test/support/runPlaywrightTests.js",
+    "test:playwright:open-browser": "node test/support/openPlaywrightBrowser.js",
     "test:react": "vitest run",
     "test:package": "grunt test:package",
     "test:proxy": "npm run build && esr test/interception-proxy/server.ts",

test/common/modules/interception_proxy_client.js

@@ -188,7 +188,7 @@ define(['ably', 'shared_helper'], function (Ably, helper) {
       } else {
         // assume it's the response to our startInterception call; TODO sort this out
         if ('error' in message) {
-          this.onFailedToStartInterception(message.error);
+          this.onFailedToStartInterception(new Error(message.error.message));
         } else {
           this.onStartedInterception();
         }

test/support/openPlaywrightBrowser.js

@@ -0,0 +1,5 @@
+const { openPlaywrightBrowser } = require('./playwrightHelpers');
+
+(async function run() {
+  await openPlaywrightBrowser(false /* headless */);
+})();

test/support/playwrightHelpers.js

@@ -0,0 +1,28 @@
+const playwright = require('playwright');
+const playwrightBrowsers = ['chromium', 'firefox', 'webkit'];
+
+async function openPlaywrightBrowser(headless) {
+  const browserEnv = process.env.PLAYWRIGHT_BROWSER;
+
+  if (!playwrightBrowsers.includes(browserEnv)) {
+    throw new Error(
+      `PLAYWRIGHT_BROWSER environment variable must be one of: ${playwrightBrowsers.join(
+        ', ',
+      )}. Currently: ${browserEnv}`,
+    );
+  }
+
+  const browserType = playwright[browserEnv];
+
+  // TODO undo this, trust the certs (it’s risky stuff though especially on e.g. a developer’s Mac where this potentially has global effect, although I guess it’s less risky given that we’re running as a different user)
+  const browser = await browserType.launch({ headless });
+  // bypass localhost so that the proxy doesn’t need to be running in order for us to contact the control API to tell it to be started; TODO there is quite possibly a less convoluted way of starting the proxy in this case, also think in a more holistic manner about the various ways in which we make sure that only certain traffic is intercepted (there are notes dotted around about this)
+  const page = await browser.newPage({
+    proxy: { server: 'localhost:8080', bypass: 'localhost' },
+    ignoreHTTPSErrors: true,
+  });
+
+  return { browserType, browser, page };
+}
+
+module.exports = { openPlaywrightBrowser };

test/support/runPlaywrightTests.js

@@ -1,23 +1,17 @@
-const playwright = require('playwright');
 const path = require('path');
 const MochaServer = require('../web_server');
 const fs = require('fs');
 const jUnitDirectoryPath = require('./junit_directory_path');
+const { openPlaywrightBrowser } = require('./playwrightHelpers');
 
 const port = process.env.PORT || 3000;
 const host = 'localhost';
-const playwrightBrowsers = ['chromium', 'firefox', 'webkit'];
 const mochaServer = new MochaServer(/* playwrightTest: */ true);
 
-const runTests = async (browserType) => {
+const runTests = async () => {
+  const { browserType, browser, page } = await openPlaywrightBrowser(true /* headless */);
+
   await mochaServer.listen();
-  // TODO undo this, trust the certs (it’s risky stuff though especially on e.g. a developer’s Mac where this potentially has global effect, although I guess it’s less risky given that we’re running as a different user)
-  const browser = await browserType.launch();
-  // bypass localhost so that the proxy doesn’t need to be running in order for us to contact the control API to tell it to be started; TODO there is quite possibly a less convoluted way of starting the proxy in this case, also think in a more holistic manner about the various ways in which we make sure that only certain traffic is intercepted (there are notes dotted around about this)
-  const page = await browser.newPage({
-    proxy: { server: 'localhost:8080', bypass: 'localhost' },
-    ignoreHTTPSErrors: true,
-  });
   await page.goto(`http://${host}:${port}`);
 
   console.log(`\nrunning tests in ${browserType.name()}`);
@@ -72,17 +66,7 @@ const runTests = async (browserType) => {
   let caughtError;
 
   try {
-    const browserEnv = process.env.PLAYWRIGHT_BROWSER;
-
-    if (!playwrightBrowsers.includes(browserEnv)) {
-      throw new Error(
-        `PLAYWRIGHT_BROWSER environment variable must be one of: ${playwrightBrowsers.join(
-          ', ',
-        )}. Currently: ${browserEnv}`,
-      );
-    }
-
-    await runTests(playwright[browserEnv]);
+    await runTests();
   } catch (error) {
     // save error for now, we must ensure we end mocha web server first.
     // if we end current process too early, mocha web server will be left running,