test: remove unnecessary noop function args to mustCall()

test/.eslintrc.yaml

@@ -46,6 +46,8 @@ rules:
       message: Use Number.isNaN() instead of the global isNaN() function.
     - selector: VariableDeclarator > CallExpression:matches([callee.name='debuglog'], [callee.property.name='debuglog']):not([arguments.0.value='test'])
       message: Use 'test' as debuglog value in tests.
+    - selector: CallExpression:matches([callee.object.name="common"][callee.property.name=/^mustCall/],[callee.name="mustCall"],[callee.name="mustCallAtLeast"])>:first-child[type=/FunctionExpression$/][body.body.length=0]
+      message: Do not use an empty function, omit the parameter altogether.
 
   # Custom rules in tools/eslint-rules
   node-core/prefer-assert-iferror: error

test/async-hooks/test-http-agent-handle-reuse-parallel.js

@@ -34,7 +34,7 @@ const verifyRequest = (idx) => (res) => {
     socket = res.socket;
   }
 
-  res.on('data', common.mustCallAtLeast(() => {}));
+  res.on('data', common.mustCallAtLeast());
   res.on('end', common.mustCall(() => {
     if (++responses === 2) {
       // Clean up to let the event loop stop.

test/async-hooks/test-http-agent-handle-reuse-serial.js

@@ -47,7 +47,7 @@ const server = http.createServer(common.mustCall((req, res) => {
     // Check that request and response share their socket.
     assert.strictEqual(r1.socket, socket);
 
-    res.on('data', common.mustCallAtLeast(() => {}));
+    res.on('data', common.mustCallAtLeast());
     res.on('end', common.mustCall(() => {
       // setImmediate() to give the agent time to register the freed socket.
       setImmediate(common.mustCall(() => {
@@ -70,7 +70,7 @@ const server = http.createServer(common.mustCall((req, res) => {
           // Empty payload, to hit the “right” code path.
           r2.end('');
 
-          res.on('data', common.mustCallAtLeast(() => {}));
+          res.on('data', common.mustCallAtLeast());
           res.on('end', common.mustCall(() => {
             // Clean up to let the event loop stop.
             server.close();

test/known_issues/test-http-path-contains-unicode.js

@@ -14,8 +14,7 @@ assert.strictEqual(expected, '/caf\u{e9}\u{1f436}');
 
 const server = http.createServer(common.mustCall(function(req, res) {
   assert.strictEqual(req.url, expected);
-  req.on('data', common.mustCall(function() {
-  })).on('end', common.mustCall(function() {
+  req.on('data', common.mustCall()).on('end', common.mustCall(function() {
     server.close();
     res.writeHead(200);
     res.end('hello world\n');

test/parallel/test-async-hooks-http-agent-destroy.js

@@ -50,7 +50,7 @@ const server = http.createServer(common.mustCall((req, res) => {
     // Check that request and response share their socket.
     assert.strictEqual(r1.socket, socket);
 
-    res.on('data', common.mustCallAtLeast(() => {}));
+    res.on('data', common.mustCallAtLeast());
     res.on('end', common.mustCall(() => {
       // setImmediate() to give the agent time to register the freed socket.
       setImmediate(common.mustCall(() => {
@@ -66,7 +66,7 @@ const server = http.createServer(common.mustCall((req, res) => {
           // Empty payload, to hit the “right” code path.
           r2.end('');
 
-          res.on('data', common.mustCallAtLeast(() => {}));
+          res.on('data', common.mustCallAtLeast());
           res.on('end', common.mustCall(() => {
             // Clean up to let the event loop stop.
             server.close();

test/parallel/test-async-hooks-http-agent.js

@@ -40,7 +40,7 @@ const server = http.createServer(common.mustCall((req, res) => {
     // Check that request and response share their socket.
     assert.strictEqual(r1.socket, socket);
 
-    res.on('data', common.mustCallAtLeast(() => {}));
+    res.on('data', common.mustCallAtLeast());
     res.on('end', common.mustCall(() => {
       // setImmediate() to give the agent time to register the freed socket.
       setImmediate(common.mustCall(() => {
@@ -62,7 +62,7 @@ const server = http.createServer(common.mustCall((req, res) => {
           // Empty payload, to hit the “right” code path.
           r2.end('');
 
-          res.on('data', common.mustCallAtLeast(() => {}));
+          res.on('data', common.mustCallAtLeast());
           res.on('end', common.mustCall(() => {
             // Clean up to let the event loop stop.
             server.close();

test/parallel/test-cluster-fork-windowsHide.js

@@ -20,8 +20,7 @@ if (!process.argv[2]) {
     { detached: true, stdio: ['ignore', 'ignore', 'ignore', 'ipc'] });
 
   const messageHandlers = {
-    workerOnline: common.mustCall((msg) => {
-    }),
+    workerOnline: common.mustCall(),
     mainWindowHandle: common.mustCall((msg) => {
       assert.match(msg.value, /0\s*/);
     }),

test/parallel/test-cluster-ipc-throw.js

@@ -17,7 +17,7 @@ if (cluster.isPrimary) {
   }));
 } else {
   assert(process.env.PORT);
-  process.on('uncaughtException', common.mustCall((e) => {}));
+  process.on('uncaughtException', common.mustCall());
   server.listen(process.env.PORT);
   server.on('error', common.mustCall((e) => {
     cluster.worker.disconnect();

test/parallel/test-cluster-worker-kill-signal.js

@@ -13,7 +13,7 @@ if (cluster.isWorker) {
   const http = require('http');
   const server = http.Server(() => { });
 
-  server.once('listening', common.mustCall(() => { }));
+  server.once('listening', common.mustCall());
   server.listen(0, '127.0.0.1');
 
 } else if (cluster.isMaster) {

test/parallel/test-cluster-worker-kill.js

@@ -35,7 +35,7 @@ if (cluster.isWorker) {
   const http = require('http');
   const server = http.Server(() => { });
 
-  server.once('listening', common.mustCall(() => { }));
+  server.once('listening', common.mustCall());
   server.listen(0, '127.0.0.1');
 
 } else if (cluster.isPrimary) {

test/parallel/test-common.js

@@ -51,14 +51,17 @@ const { join } = require('path');
 
 // common.mustCall() tests
 assert.throws(function() {
+  // eslint-disable-next-line no-restricted-syntax
   common.mustCall(function() {}, 'foo');
 }, /^TypeError: Invalid exact value: foo$/);
 
 assert.throws(function() {
+  // eslint-disable-next-line no-restricted-syntax
   common.mustCall(function() {}, /foo/);
 }, /^TypeError: Invalid exact value: \/foo\/$/);
 
 assert.throws(function() {
+  // eslint-disable-next-line no-restricted-syntax
   common.mustCallAtLeast(function() {}, /foo/);
 }, /^TypeError: Invalid minimum value: \/foo\/$/);
 

test/parallel/test-domain-multi.js

@@ -73,5 +73,5 @@ const server = http.createServer((req, res) => {
     res.pipe(process.stdout);
   });
 
-  c.on('error', common.mustCall((er) => { }));
+  c.on('error', common.mustCall());
 });

test/parallel/test-fs-watchfile-bigint.js

@@ -66,4 +66,4 @@ const watcher =
 
 // 'stop' should only be emitted once - stopping a stopped watcher should
 // not trigger a 'stop' event.
-watcher.on('stop', common.mustCall(function onStop() {}));
+watcher.on('stop', common.mustCall());

test/parallel/test-fs-watchfile.js

@@ -80,7 +80,7 @@ const watcher =
 
 // 'stop' should only be emitted once - stopping a stopped watcher should
 // not trigger a 'stop' event.
-watcher.on('stop', common.mustCall(function onStop() {}));
+watcher.on('stop', common.mustCall());
 
 // Watch events should callback with a filename on supported systems.
 // Omitting AIX. It works but not reliably.

test/parallel/test-http2-socket-proxy-handler-for-has.js

@@ -29,8 +29,7 @@ server.listen(common.mustCall(() => {
   const req = client.request({});
   req.on('response', common.mustCall((headers, flags) => {
     console.log(headers);
-    server.close(common.mustCall(() => {
-    }));
+    server.close(common.mustCall());
   }));
   req.on('end', common.mustCall(() => {
     client.close();

test/parallel/test-https-max-header-size-per-stream.js

@@ -98,7 +98,7 @@ const certFixture = {
 
   // clientError may be emitted multiple times when header is larger than
   // maxHeaderSize.
-  server.on('clientError', common.mustCallAtLeast(() => {}, 1));
+  server.on('clientError', common.mustCallAtLeast(1));
 
   server.listen(0, common.mustCall(() => {
     const client = tls.connect({

test/parallel/test-spawn-cmd-named-pipe.js

@@ -17,8 +17,7 @@ if (!process.argv[2]) {
   const stdoutPipeName = `\\\\.\\pipe\\${pipeNamePrefix}.stdout`;
 
   const stdinPipeServer = net.createServer(function(c) {
-    c.on('end', common.mustCall(function() {
-    }));
+    c.on('end', common.mustCall());
     c.end('hello');
   });
   stdinPipeServer.listen(stdinPipeName);

test/parallel/test-stream-pipeline-with-empty-string.js

@@ -11,7 +11,7 @@ async function runTest() {
   await pipeline(
     '',
     new PassThrough({ objectMode: true }),
-    common.mustCall(() => { })
+    common.mustCall(),
   );
 }
 

test/parallel/test-tls-client-reject.js

@@ -59,8 +59,7 @@ function unauthorized() {
     }));
     socket.on('end', () => rejectUnauthorized());
   }));
-  socket.once('session', common.mustCall(() => {
-  }));
+  socket.once('session', common.mustCall());
   socket.on('error', common.mustNotCall());
   socket.end('ok');
 }

test/parallel/test-tls-client-resume.js

@@ -61,8 +61,7 @@ server.listen(0, common.mustCall(function() {
       reconnect();
   }));
 
-  client1.on('data', common.mustCall((d) => {
-  }));
+  client1.on('data', common.mustCall());
 
   client1.once('session', common.mustCall((session) => {
     console.log('session1');

test/parallel/test-tls-disable-renegotiation.js

@@ -88,9 +88,7 @@ server.listen(0, common.mustCall(() => {
       }));
     }));
     assert.strictEqual(ok, true);
-    client.on('secureConnect', common.mustCall(() => {
-    }));
-    client.on('secure', common.mustCall(() => {
-    }));
+    client.on('secureConnect', common.mustCall());
+    client.on('secure', common.mustCall());
   }));
 }));

test/parallel/test-tls-getprotocol.js

@@ -23,9 +23,8 @@ const serverConfig = {
   cert: fixtures.readKey('agent2-cert.pem')
 };
 
-const server = tls.createServer(serverConfig, common.mustCall(function() {
-
-}, clientConfigs.length)).listen(0, common.localhostIPv4, function() {
+const server = tls.createServer(serverConfig, common.mustCall(clientConfigs.length))
+.listen(0, common.localhostIPv4, function() {
   let connected = 0;
   clientConfigs.forEach(function(v) {
     tls.connect({

test/parallel/test-tls-ocsp-callback.js

@@ -87,7 +87,7 @@ function test(testOptions, cb) {
       requestOCSP: testOptions.ocsp,
       secureOptions: testOptions.ocsp ? 0 : SSL_OP_NO_TICKET,
       rejectUnauthorized: false
-    }, common.mustCall(() => { }, requestCount));
+    }, common.mustCall(requestCount));
 
     client.on('OCSPResponse', common.mustCall((resp) => {
       if (testOptions.response) {

test/parallel/test-x509-escaping.js

@@ -499,8 +499,6 @@ const { hasOpenSSL3 } = common;
     tls.connect(port, {
       ca: cert,
       servername,
-    }, common.mustCall(() => {
-      // Do nothing, the server will close the connection.
-    }));
+    }, common.mustCall());
   }));
 }