feat: Deno.test() sanitizes ops and resources (#4399)

This PR brings assertOps and assertResources sanitizers to Deno.test() API.

assertOps checks that test doesn't leak async ops, ie. there are no unresolved
promises originating from Deno APIs. Enabled by default, can be disabled using 
Deno.TestDefinition.disableOpSanitizer.

assertResources checks that test doesn't leak resources, ie. all resources used
in test are closed. For example; if a file is opened during a test case it must be
explicitly closed before test case finishes. It's most useful for asynchronous
generators. Enabled by default, can be disabled using 
Deno.TestDefinition.disableResourceSanitizer.

We've used those sanitizers in internal runtime tests and it proved very useful in
surfacing incorrect tests which resulted in interference between the tests.

All tests have been sanitized.

Closes #4208

1 files changed, 33 insertions, 34 deletions

diff --git a/std/examples/chat/server_test.ts b/std/examples/chat/server_test.ts
index c63453a19..8004055a4 100644
--- a/std/examples/chat/server_test.ts
+++ b/std/examples/chat/server_test.ts
@@ -3,10 +3,12 @@ import { assert, assertEquals } from "../../testing/asserts.ts";
 import { TextProtoReader } from "../../textproto/mod.ts";
 import { BufReader } from "../../io/bufio.ts";
 import { connectWebSocket, WebSocket } from "../../ws/mod.ts";
+import { delay } from "../../util/async.ts";
 
-let server: Deno.Process | undefined;
-async function startServer(): Promise<void> {
-  server = Deno.run({
+const { test, build } = Deno;
+
+async function startServer(): Promise<Deno.Process> {
+  const server = Deno.run({
     args: [Deno.execPath(), "--allow-net", "--allow-read", "server.ts"],
     cwd: "examples/chat",
     stdout: "piped"
@@ -17,54 +19,51 @@ async function startServer(): Promise<void> {
     const s = await r.readLine();
     assert(s !== Deno.EOF && s.includes("chat server starting"));
   } catch {
+    server.stdout!.close();
     server.close();
   }
-}
 
-const { test, build } = Deno;
+  return server;
+}
 
 // TODO: https://github.com/denoland/deno/issues/4108
 const skip = build.os == "win";
 
 test({
   skip,
-  name: "beforeAll",
-  async fn() {
-    await startServer();
-  }
-});
-
-test({
-  skip,
   name: "GET / should serve html",
   async fn() {
-    const resp = await fetch("http://127.0.0.1:8080/");
-    assertEquals(resp.status, 200);
-    assertEquals(resp.headers.get("content-type"), "text/html");
-    const html = await resp.body.text();
-    assert(html.includes("ws chat example"), "body is ok");
+    const server = await startServer();
+    try {
+      const resp = await fetch("http://127.0.0.1:8080/");
+      assertEquals(resp.status, 200);
+      assertEquals(resp.headers.get("content-type"), "text/html");
+      const html = await resp.body.text();
+      assert(html.includes("ws chat example"), "body is ok");
+    } finally {
+      server.close();
+      server.stdout!.close();
+    }
+    await delay(10);
   }
 });
 
-let ws: WebSocket | undefined;
-
 test({
   skip,
   name: "GET /ws should upgrade conn to ws",
   async fn() {
-    ws = await connectWebSocket("http://127.0.0.1:8080/ws");
-    const it = ws.receive();
-    assertEquals((await it.next()).value, "Connected: [1]");
-    ws.send("Hello");
-    assertEquals((await it.next()).value, "[1]: Hello");
-  }
-});
-
-test({
-  skip,
-  name: "afterAll",
-  fn() {
-    server?.close();
-    ws?.conn.close();
+    const server = await startServer();
+    let ws: WebSocket | undefined;
+    try {
+      ws = await connectWebSocket("http://127.0.0.1:8080/ws");
+      const it = ws.receive();
+      assertEquals((await it.next()).value, "Connected: [1]");
+      ws.send("Hello");
+      assertEquals((await it.next()).value, "[1]: Hello");
+    } finally {
+      server.close();
+      server.stdout!.close();
+      ws!.conn.close();
+    }
   }
 });