test: simplify test-tls-set-secure-context

Instead of recursively scheduling makeRemainingRequests and ignoring its
outcome, safely loop within the async function.

Avoid unncessary async lambda functions passed to assert.rejects.

Use events.once() to simplify control flow in makeRequest, instead of
manually constructing a Promise.

PR-URL: #43878
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

test/parallel/test-tls-set-secure-context.js

@@ -9,7 +9,9 @@ if (!common.hasCrypto)
 // secure context is changed.
 
 const assert = require('assert');
+const events = require('events');
 const https = require('https');
+const timers = require('timers/promises');
 const fixtures = require('../common/fixtures');
 const credentialOptions = [
   {
@@ -43,10 +45,10 @@ server.listen(0, common.mustCall(() => {
   const { port } = server.address();
   const firstRequest = makeRequest(port, 1);
 
-  async function makeRemainingRequests() {
+  (async function makeRemainingRequests() {
     // Wait until the first request is guaranteed to have been handled.
-    if (!firstResponse) {
-      return setImmediate(makeRemainingRequests);
+    while (!firstResponse) {
+      await timers.setImmediate();
     }
 
     assert.strictEqual(await makeRequest(port, 2), 'success');
@@ -56,53 +58,38 @@ server.listen(0, common.mustCall(() => {
     const errorMessageRegex = common.hasOpenSSL3 ?
       /^Error: self-signed certificate$/ :
       /^Error: self signed certificate$/;
-    await assert.rejects(async () => {
-      await makeRequest(port, 3);
-    }, errorMessageRegex);
+    await assert.rejects(makeRequest(port, 3), errorMessageRegex);
 
     server.setSecureContext(credentialOptions[0]);
     assert.strictEqual(await makeRequest(port, 4), 'success');
 
     server.setSecureContext(credentialOptions[1]);
     firstResponse.end('fun!');
-    await assert.rejects(async () => {
-      await makeRequest(port, 5);
-    }, errorMessageRegex);
+    await assert.rejects(makeRequest(port, 5), errorMessageRegex);
 
     assert.strictEqual(await firstRequest, 'multi-request-success-fun!');
     server.close();
-  }
-
-  makeRemainingRequests();
+  })().then(common.mustCall());
 }));
 
-function makeRequest(port, id) {
-  return new Promise((resolve, reject) => {
-    const options = {
-      rejectUnauthorized: true,
-      ca: credentialOptions[0].ca,
-      servername: 'agent1',
-      headers: { id }
-    };
-
-    let errored = false;
-    https.get(`https://localhost:${port}`, options, (res) => {
-      let response = '';
-
-      res.setEncoding('utf8');
-
-      res.on('data', (chunk) => {
-        response += chunk;
-      });
-
-      res.on('end', common.mustCall(() => {
-        resolve(response);
-      }));
-    }).on('error', (err) => {
-      errored = true;
-      reject(err);
-    }).on('finish', () => {
-      assert.strictEqual(errored, false);
-    });
-  });
+async function makeRequest(port, id) {
+  const options = {
+    rejectUnauthorized: true,
+    ca: credentialOptions[0].ca,
+    servername: 'agent1',
+    headers: { id },
+    agent: new https.Agent()
+  };
+
+  const req = https.get(`https://localhost:${port}`, options);
+
+  let errored = false;
+  req.on('error', () => errored = true);
+  req.on('finish', () => assert.strictEqual(errored, false));
+
+  const [res] = await events.once(req, 'response');
+  res.setEncoding('utf8');
+  let response = '';
+  for await (const chunk of res) response += chunk;
+  return response;
 }