Spawn a code-server instance for each test suite

This uses the current dev build by default but can be overidden with
CODE_SERVER_TEST_ENTRY (for example to test a release or some other
version).

Each instance has a separate state directory. This should make
parallelization work.

This also means you are no longer required to specify the password and
address yourself (or the extension directory once we add a test
extension). `yarn test:e2e` should just work as-is.

Lastly, it means the tests are no longer subject to yarn watch randomly
restarting.

test/e2e/baseFixture.ts

@@ -1,12 +1,47 @@
+import { field, logger } from "@coder/logger"
 import { test as base } from "@playwright/test"
-import { CodeServer } from "./models/CodeServer"
+import { CodeServer, CodeServerPage } from "./models/CodeServer"
 
-export const test = base.extend<{ codeServerPage: CodeServer }>({
-  codeServerPage: async ({ page }, use) => {
-    const codeServer = new CodeServer(page)
-    await codeServer.navigate()
-    await use(codeServer)
+/**
+ * Wraps `test.describe` to create and manage an instance of code-server. If you
+ * don't use this you will need to create your own code-server instance and pass
+ * it to `test.use`.
+ */
+export const describe = (name: string, fn: (codeServer: CodeServer) => void) => {
+  test.describe(name, () => {
+    // This will spawn on demand so nothing is necessary on before.
+    const codeServer = new CodeServer(name)
+
+    // Kill code-server after the suite has ended. This may happen even without
+    // doing it explicitly but it seems prudent to be sure.
+    test.afterAll(async () => {
+      await codeServer.close()
+    })
+
+    // This makes `codeServer` available to the extend call below.
+    test.use({ codeServer })
+
+    fn(codeServer)
+  })
+}
+
+interface TestFixtures {
+  codeServer: CodeServer
+  codeServerPage: CodeServerPage
+}
+
+/**
+ * Create a test that spawns code-server if necessary and ensures the page is
+ * ready.
+ */
+export const test = base.extend<TestFixtures>({
+  codeServer: undefined, // No default; should be provided through `test.use`.
+  codeServerPage: async ({ codeServer, page }, use) => {
+    const codeServerPage = new CodeServerPage(codeServer, page)
+    await codeServerPage.navigate()
+    await use(codeServerPage)
   },
 })
 
+/** Shorthand for test.expect. */
 export const expect = test.expect