Fix end-to-end tests post Next.js migration

- In order to run either the mock tests or the end-to-end tests, we need a dev server running in CI. Previously, we would spawn that manually from inside of a script. Now, we start that from inside of the action that does the testing. This means that if you want to run the tests locally, you'll also need your local dev server running (which was already true).
- Add necessary parts of the `test` folder to public. This means that we will be able to run against preview branches as well.
- Add a github action for setting up Next.js with a cache, so we only have to copy one line everywhere, not an entire step. It would be nice if we could further refactor out the test stripes, because a lot of things are repeated 9 times.
- Remove the `dev-server.js` file. If we're going to use next.js, then we should try and keep our config as out-of-the-box as possible, in order to allow us to stay up-to-date. The fact that the `test` folder has to be available on the development server for the tests to run at all seems like the real problem here. A good follow-on task would be to sort out the best way to handle those files in the test/dev environment.
- Go back to node 14 for lock file. I didn't realize when I changed this that we were stuck on such an outdated node version. We should fix this ASAP, but until then, let's stick with what was working, just to minimize the factors that have gone into resolving all of the failing tests.
- Add a `waitingFor` field to the `waitUntil` method used in tests. It's really frustrating when a test fails and all it says is `timed out`. Like... timed out while waiting for *what*? Test failures should guide you to the place of failure as quickly as possible.
- By default, wait for 10 seconds. If something doesn't appear in the DOM in 10 seconds, that should be considered a failure.
- Log more from playwright tests. This could be annoying, maybe we should tune it, but it's nice to know what's going on in these tests, and we're only going to look at the output when something is failing anyways, so it may as well be verbose.
- Log the time that tests take. We started with a lot of timeouts. I fixed them, but sometimes it was hard to see what tests were timing out. Now, when a test completes, we emit some test stats. Eventually, it might be nice to just like... use a real test runner... but this is fine for now.
- Mock test URLs like http://localhost:8080/recording/24c0bc00-fdad-4e5e-b2ac-23193ba3ac6b?mock=1 show a gray screen after a few seconds. If you remove the `mock` query param then the screen shows up totally normally. I'm not sure of the exact interactions here. Let's figure this out in a follow-on task.
- Add `test/run` and `test/mock/run` scripts for running the rest runners locally, and taking care of making sure that the files get shuffled around correctly before and after, and that the dev server is running, etc.
- Add README instructions about `.env` files and new test run scripts.

That's true! We still have flaky, intermittent tests. The goal of this PR was to get things to *run*, getting them to pass is a future us problem!

I'm going to put these into a notion doc as well, but documenting here couldn't hurt. Three things that tripped me up on this PR:

- *any* merge conflicts mean actions *will not run at all*. If you have a branch and it's unclear why actions aren't kicking off, make sure you check for and resolve merge conflicts.
- When using actions that are type `javascript` your `inputs` get automatically turned into environment variables, which is convenient. However **when using `composite` actions this won't happen**. You have to manually pass the environment variables in with an [expression](https://docs.github.com/en/actions/learn-github-actions/expressions).
- The `checkout` action that we use all the time performs a strict `clean` of the directory that it's about to clone into! So, if you are trying to do some sort of caching or otherwise unloading assets into a dir that you also need to do `git checkout XXXX` in (with the checkout action), you either need to checkout *first*, or you can use `[clean: false](https://github.com/actions/checkout#usage)` I think, though I haven't actually tried this.
- Actions are somewhat limited. More details here: actions/runner#646

Fixes replayio#4313

.env.sample

@@ -0,0 +1,2 @@
+NEXT_PUBLIC_API_URL=https://api.replay.io/v1/graphql
+NEXT_PUBLIC_DISPATCH_URL=wss://dispatch.replay.io

.github/actions/mockTest/action.yml

@@ -1,6 +1,15 @@
-name: "Mock Test"
+name: "Mock Tests"
 description: "Run mock tests"
-
 runs:
-  using: "node12"
-  main: "./main.js"
+  using: "composite"
+  steps:
+    - name: Copy .env file
+      run: cp .env.sample .env
+      shell: bash
+    - name: Start Next.js development server
+      run: ./node_modules/.bin/next dev -p 8080 &
+      shell: bash
+    - run: node ${{ github.action_path }}/main.js
+      shell: bash
+      env:
+        DEBUG: "pw:api"

.github/actions/mockTest/main.js

@@ -5,42 +5,14 @@ const devtools = `${__dirname}/../../..`;
 
 console.log(new Date(), "Start");
 
-spawnCheckedRetry("npm", ["install"], { cwd: devtools, stdio: "inherit" });
-const devServerProcess = spawn("node_modules/.bin/webpack", ["serve"], {
-  cwd: devtools,
-  stdio: ["inherit", "pipe", "inherit"],
-});
-
-console.log(new Date(), "Installed devtools and started webpack build");
-
 (async function () {
-  console.log("Waiting for Webpack server start");
-  await Promise.race([
-    new Promise(r => {
-      devServerProcess.stdout.on("data", chunk => {
-        process.stdout.write(chunk);
-        // Once the dev server starts outputting stuff, we assume it has started
-        // its server and it is safe to curl.
-        r();
-      });
-    }),
-    new Promise(r => setTimeout(r, 10 * 1000)).then(() => {
-      throw new Error("Failed to start dev server");
-    }),
-  ]);
-  console.log("Waiting for Webpack build");
-
-  // Wait for the initial Webpack build to complete before
-  // trying to run the tests so the tests don't run
-  // the risk of timing out if the build itself is slow.
   spawnChecked(
     "curl",
-    ["--max-time", "600", "--range", "0-50", "http://localhost:8080/dist/main.js"],
+    ["--max-time", "180", "--range", "0-50", "http://localhost:8080/test/harness.js"],
     {
       stdio: "inherit",
     }
   );
-  console.log("Done Initial Webpack build");
 
   spawnChecked("node", [`${devtools}/test/mock/run`], { stdio: "inherit" });
   process.exit(0);

.github/actions/npm-install/action.yml

@@ -0,0 +1,13 @@
+name: "npm install"
+description: "Installs dependencies from npm, with caching"
+runs:
+  using: "composite"
+  steps:
+    - name: Setup node
+      uses: actions/setup-node@v2
+      with:
+        node-version: "14"
+        cache: "npm"
+    - name: Install dependencies
+      run: npm ci
+      shell: bash

.github/actions/setup-next/action.yml

@@ -0,0 +1,14 @@
+name: "Setup Next.js"
+description: "Restores the .next/cache folder"
+runs:
+  using: "composite"
+  steps:
+    - name: "Setup NextJS Cache"
+      uses: actions/cache@v2
+      with:
+        path: ${{ github.workspace }}/.next/cache
+        # Generate a new cache whenever packages or source files change.
+        key: ${{ runner.os }}-nextjs-${{ hashFiles('**/package-lock.json') }}-${{ hashFiles('**.[jt]s', '**.[jt]sx') }}
+        # If source files changed but packages didn't, rebuild from a prior cache.
+        restore-keys: |
+          ${{ runner.os }}-nextjs-${{ hashFiles('**/package-lock.json') }}-

.github/actions/test/action.yml

@@ -1,13 +1,23 @@
 name: "Test"
-description: "Run correctness tests"
+description: "Run end-to-end tests. Note that this action assumes that Node and Next.js have already been properly setup. See the setup-next task for details."
 inputs:
   stripe:
     description: "Stripe to run, in the form INDEX/TOTAL"
     required: true
-  github_ci:
-    description: "A flag to tell whether we are in CI"
-    required: false
-
 runs:
-  using: "node12"
-  main: "./main.js"
+  using: "composite"
+  steps:
+    - run: mv node_modules/node_modules.tgz ./
+      shell: bash
+    - run: tar -xzf node_modules.tgz
+      shell: bash
+    - name: Copy .env file
+      run: cp .env.sample .env
+      shell: bash
+    - name: Start Next.js development server
+      run: ./node_modules/.bin/next dev -p 8080 &
+      shell: bash
+    - run: node ${{ github.action_path }}/main.js
+      shell: bash
+      env:
+        INPUT_STRIPE: ${{ inputs.stripe }}

.github/actions/test/main.js

@@ -1,32 +1,27 @@
 const fs = require("fs");
-const { spawnSync, spawn } = require("child_process");
+const { spawnSync } = require("child_process");
 
 function spawnChecked(...args) {
-  console.log(`spawn`, args);
+  console.log(`Spawning`, args);
   const rv = spawnSync.apply(this, args);
   if (rv.status != 0 || rv.error) {
     throw new Error("Spawned process failed");
   }
+  console.log(`Spawned`, args);
 }
 
 function checkForFile(path) {
+  console.log(`Checking for file: ${path}`);
   if (!fs.existsSync(path)) {
     throw new Error(`Required file/directory does not exist: ${path}`);
   }
+  console.log(`Found ${path}`);
 }
 
-checkForFile("dist/dist.tgz");
 checkForFile("replay/replay.dmg");
 checkForFile("replay-node/macOS-replay-node");
 checkForFile("replay-driver/macOS-recordreplay.so");
 
-console.log(new Date(), "Start");
-
-spawnChecked("mv", ["dist/dist.tgz", "dist.tgz"]);
-spawnChecked("tar", ["-xzf", "dist.tgz"]);
-
-console.log(new Date(), "Unpackaged distribution");
-
 spawnChecked("hdiutil", ["attach", "replay/replay.dmg"]);
 spawnChecked("cp", ["-R", "/Volumes/Replay/Replay.app", "/Applications"]);
 try {
@@ -41,39 +36,11 @@ spawnChecked("chmod", ["+x", "replay-node/macOS-replay-node"]);
 process.env.RECORD_REPLAY_NODE = "replay-node/macOS-replay-node";
 process.env.RECORD_REPLAY_DRIVER = "replay-driver/macOS-recordreplay.so";
 
-const devServerProcess = spawn("node_modules/.bin/webpack", ["serve"], {
-  detached: true,
-  stdio: ["inherit", "pipe", "inherit"],
-});
-
 (async function () {
-  console.log("Waiting for Webpack server start");
-  await Promise.race([
-    new Promise(r => {
-      devServerProcess.stdout.on("data", chunk => {
-        process.stdout.write(chunk);
-        // Once the dev server starts outputting stuff, we assume it has started
-        // its server and it is safe to curl.
-        r();
-      });
-    }),
-    new Promise(r => setTimeout(r, 10 * 1000)).then(() => {
-      throw new Error("Failed to start dev server");
-    }),
-  ]);
-  console.log("Waiting for Webpack build");
-
-  // Wait for the initial Webpack build to complete before
-  // trying to run the tests so the tests don't run
-  // the risk of timing out if the build itself is slow.
-  spawnChecked(
-    "curl",
-    ["--max-time", "600", "--range", "0-50", "http://localhost:8080/dist/main.js"],
-    {
-      stdio: "inherit",
-    }
-  );
-  console.log("Done Initial Webpack build");
+  spawnChecked("curl", ["--max-time", "180", "--range", "0-50", "http://localhost:8080/"], {
+    stdio: "inherit",
+  });
+  console.log("Made contact with server on localhost:8080");
 
   require("../../../test/run");
 })().catch(err => {