test,lib,doc: use function declarations

Replace function expressions with function declarations in preparation
for a lint rule requiring function declarations.

PR-URL: #12711
Backport-PR-URL: #13774
Reviewed-By: Vse Mozhet Byt <[email protected]>
Reviewed-By: Gibson Fahnestock <[email protected]>

Author: Trott

doc/api/util.md

@@ -557,7 +557,7 @@ Returns `true` if the given `object` is a `Function`. Otherwise, returns
 const util = require('util');
 
 function Foo() {}
-const Bar = function() {};
+const Bar = () => {};
 
 util.isFunction({});
 // Returns: false

lib/_http_client.js

@@ -606,7 +606,7 @@ ClientRequest.prototype._deferToConnect = function(method, arguments_, cb) {
       cb();
   }
 
-  var onSocket = function() {
+  var onSocket = () => {
     if (self.socket.writable) {
       callSocketMethod();
     } else {

lib/_tls_legacy.js

@@ -425,9 +425,9 @@ CryptoStream.prototype.destroySoon = function(err) {
     // was written on this side was read from the other side.
     var self = this;
     var waiting = 1;
-    var finish = function() {
+    function finish() {
       if (--waiting === 0) self.destroy();
-    };
+    }
     this._opposite.once('end', finish);
     if (!this._finished) {
       this.once('finish', finish);

lib/crypto.js

@@ -581,11 +581,11 @@ function pbkdf2(password, salt, iterations, keylen, digest, callback) {
   // at this point, we need to handle encodings.
   var encoding = exports.DEFAULT_ENCODING;
   if (callback) {
-    var next = function(er, ret) {
+    function next(er, ret) {
       if (ret)
         ret = ret.toString(encoding);
       callback(er, ret);
-    };
+    }
     binding.PBKDF2(password, salt, iterations, keylen, digest, next);
   } else {
     var ret = binding.PBKDF2(password, salt, iterations, keylen, digest);

test/addons/make-callback/test.js

@@ -57,9 +57,9 @@ const forward = vm.runInNewContext(`
     })
 `);
 // Runs in outer context.
-const endpoint = function($Object) {
+function endpoint($Object) {
   if (Object === $Object)
     throw new Error('bad');
   return Object;
-};
+}
 assert.strictEqual(Object, makeCallback(process, forward, endpoint));

test/inspector/inspector-helper.js

@@ -120,7 +120,7 @@ function timeout(message, multiplicator) {
                     TIMEOUT * (multiplicator || 1));
 }
 
-const TestSession = function(socket, harness) {
+function TestSession(socket, harness) {
   this.mainScriptPath = harness.mainScriptPath;
   this.mainScriptId = null;
 
@@ -145,7 +145,7 @@ const TestSession = function(socket, harness) {
         buffer = buffer.slice(consumed);
     } while (consumed);
   }).on('close', () => assert(this.expectClose_, 'Socket closed prematurely'));
-};
+}
 
 TestSession.prototype.scriptUrlForId = function(id) {
   return this.scripts_[id];
@@ -302,7 +302,7 @@ TestSession.prototype.testHttpResponse = function(path, check) {
 };
 
 
-const Harness = function(port, childProcess) {
+function Harness(port, childProcess) {
   this.port = port;
   this.mainScriptPath = mainScript;
   this.stderrFilters_ = [];
@@ -327,7 +327,7 @@ const Harness = function(port, childProcess) {
     this.returnCode_ = code;
     this.running_ = false;
   });
-};
+}
 
 Harness.prototype.addStderrFilter = function(regexp, callback) {
   this.stderrFilters_.push((message) => {

test/parallel/test-assert.js

@@ -428,7 +428,7 @@ try {
 
   AnotherErrorType = class extends Error {};
 
-  const functionThatThrows = function() {
+  const functionThatThrows = () => {
     throw new AnotherErrorType('foo');
   };
 
@@ -471,6 +471,7 @@ a.throws(makeBlock(a.deepEqual, args, []));
 
 // more checking that arguments objects are handled correctly
 {
+  // eslint-disable-next-line func-style
   const returnArguments = function() { return arguments; };
 
   const someArgs = returnArguments('a');

test/parallel/test-child-process-fork-dgram.js

@@ -57,7 +57,7 @@ if (process.argv[2] === 'child') {
     });
   });
 
-  const sendMessages = function() {
+  function sendMessages() {
     const serverPort = parentServer.address().port;
 
     const timer = setInterval(function() {
@@ -81,7 +81,7 @@ if (process.argv[2] === 'child') {
         );
       }
     }, 1);
-  };
+  }
 
   parentServer.bind(0, '127.0.0.1');
 

test/parallel/test-child-process-fork-net.js

@@ -66,7 +66,7 @@ if (process.argv[2] === 'child') {
   }));
 
   // send net.Server to child and test by connecting
-  const testServer = function(callback) {
+  function testServer(callback) {
 
     // destroy server execute callback when done
     const progress = new ProgressTracker(2, function() {
@@ -95,7 +95,7 @@ if (process.argv[2] === 'child') {
     server.listen(0);
 
     // handle client messages
-    const messageHandlers = function(msg) {
+    function messageHandlers(msg) {
 
       if (msg.what === 'listening') {
         // make connections
@@ -117,13 +117,13 @@ if (process.argv[2] === 'child') {
         child.removeListener('message', messageHandlers);
         callback();
       }
-    };
+    }
 
     child.on('message', messageHandlers);
-  };
+  }
 
   // send net.Socket to child
-  const testSocket = function(callback) {
+  function testSocket(callback) {
 
     // create a new server and connect to it,
     // but the socket will be handled by the child
@@ -158,7 +158,7 @@ if (process.argv[2] === 'child') {
         server.close();
       });
     });
-  };
+  }
 
   // create server and send it to child
   let serverSuccess = false;

test/parallel/test-child-process-fork-net2.js

@@ -123,7 +123,7 @@ if (process.argv[2] === 'child') {
 
   server.listen(0, '127.0.0.1');
 
-  let closeServer = function() {
+  function closeServer() {
     server.close();
 
     setTimeout(function() {
@@ -132,7 +132,7 @@ if (process.argv[2] === 'child') {
       child2.send('close');
       child3.disconnect();
     }, 200);
-  };
+  }
 
   process.on('exit', function() {
     assert.strictEqual(disconnected, count);

test/parallel/test-child-process-spawn-typeerror.js

@@ -57,7 +57,7 @@ assert.throws(function() {
 // Argument types for combinatorics
 const a = [];
 const o = {};
-const c = function c() {};
+function c() {}
 const s = 'string';
 const u = undefined;
 const n = null;

test/parallel/test-cluster-disconnect.js

@@ -17,7 +17,7 @@ if (cluster.isWorker) {
   const servers = 2;
 
   // test a single TCP server
-  const testConnection = function(port, cb) {
+  const testConnection = (port, cb) => {
     const socket = net.connect(port, '127.0.0.1', () => {
       // buffer result
       let result = '';
@@ -31,7 +31,7 @@ if (cluster.isWorker) {
   };
 
   // test both servers created in the cluster
-  const testCluster = function(cb) {
+  const testCluster = (cb) => {
     let done = 0;
 
     for (let i = 0; i < servers; i++) {
@@ -46,7 +46,7 @@ if (cluster.isWorker) {
   };
 
   // start two workers and execute callback when both is listening
-  const startCluster = function(cb) {
+  const startCluster = (cb) => {
     const workers = 8;
     let online = 0;
 
@@ -60,7 +60,7 @@ if (cluster.isWorker) {
     }
   };
 
-  const test = function(again) {
+  const test = (again) => {
     //1. start cluster
     startCluster(common.mustCall(() => {
       //2. test cluster

test/parallel/test-cluster-master-error.js

@@ -80,7 +80,7 @@ if (cluster.isWorker) {
     // Check that the cluster died accidentally (non-zero exit code)
     masterExited = !!code;
 
-    const pollWorkers = function() {
+    const pollWorkers = () => {
       // When master is dead all workers should be dead too
       let alive = false;
       workers.forEach((pid) => alive = common.isAlive(pid));

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

@@ -47,7 +47,7 @@ if (cluster.isWorker) {
     assert.strictEqual(code, 0);
 
     // check worker process status
-    const pollWorker = function() {
+    const pollWorker = () => {
       alive = common.isAlive(pid);
       if (alive) {
         setTimeout(pollWorker, 50);

test/parallel/test-cluster-message.js

@@ -59,7 +59,7 @@ if (cluster.isWorker) {
 
 
   let client;
-  const check = function(type, result) {
+  const check = (type, result) => {
     checks[type].receive = true;
     checks[type].correct = result;
     console.error('check', checks);

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

@@ -82,7 +82,7 @@ if (cluster.isWorker) {
     }
   }));
 
-  const finish_test = function() {
+  const finish_test = () => {
     try {
       checkResults(expected_results, results);
     } catch (exc) {

test/parallel/test-console-not-call-toString.js

@@ -2,7 +2,7 @@
 require('../common');
 const assert = require('assert');
 
-const func = function() {};
+function func() {}
 let toStringCalled = false;
 func.toString = function() {
   toStringCalled = true;

test/parallel/test-debugger-pid.js

@@ -11,7 +11,7 @@ const interfacer = spawn(process.execPath, ['debug', '-p', '655555']);
 console.error(process.execPath, 'debug', '-p', '655555');
 interfacer.stdout.setEncoding('utf-8');
 interfacer.stderr.setEncoding('utf-8');
-const onData = function(data) {
+const onData = (data) => {
   data = (buffer + data).split('\n');
   buffer = data.pop();
   data.forEach(function(line) {

test/parallel/test-event-emitter-add-listeners.js

@@ -47,8 +47,8 @@ const EventEmitter = require('events');
 }
 
 {
-  const listen1 = function listen1() {};
-  const listen2 = function listen2() {};
+  const listen1 = () => {};
+  const listen2 = () => {};
   const ee = new EventEmitter();
 
   ee.once('newListener', function() {

test/parallel/test-event-emitter-once.js

@@ -12,9 +12,9 @@ e.emit('hello', 'a', 'b');
 e.emit('hello', 'a', 'b');
 e.emit('hello', 'a', 'b');
 
-const remove = function() {
+function remove() {
   common.fail('once->foo should not be emitted');
-};
+}
 
 e.once('foo', remove);
 e.removeListener('foo', remove);

test/parallel/test-fs-access.js

@@ -7,19 +7,19 @@ const doesNotExist = path.join(common.tmpDir, '__this_should_not_exist');
 const readOnlyFile = path.join(common.tmpDir, 'read_only_file');
 const readWriteFile = path.join(common.tmpDir, 'read_write_file');
 
-const removeFile = function(file) {
+const removeFile = (file) => {
   try {
     fs.unlinkSync(file);
   } catch (err) {
     // Ignore error
   }
 };
 
-const createFileWithPerms = function(file, mode) {
+function createFileWithPerms(file, mode) {
   removeFile(file);
   fs.writeFileSync(file, '');
   fs.chmodSync(file, mode);
-};
+}
 
 common.refreshTmpDir();
 createFileWithPerms(readOnlyFile, 0o444);

test/parallel/test-fs-link.js

@@ -11,11 +11,11 @@ const srcPath = path.join(common.tmpDir, 'hardlink-target.txt');
 const dstPath = path.join(common.tmpDir, 'link1.js');
 fs.writeFileSync(srcPath, 'hello world');
 
-const callback = function(err) {
-  if (err) throw err;
+function callback(err) {
+  assert.ifError(err);
   const dstContent = fs.readFileSync(dstPath, 'utf8');
   assert.strictEqual('hello world', dstContent);
-};
+}
 
 fs.link(srcPath, dstPath, common.mustCall(callback));
 

test/parallel/test-fs-read-stream-fd-leak.js

@@ -29,7 +29,7 @@ function testLeak(endFn, callback) {
   let i = 0;
   let check = 0;
 
-  const checkFunction = function() {
+  function checkFunction() {
     if (openCount !== 0 && check < totalCheck) {
       check++;
       setTimeout(checkFunction, 100);
@@ -44,7 +44,7 @@ function testLeak(endFn, callback) {
 
     openCount = 0;
     callback && setTimeout(callback, 100);
-  };
+  }
 
   setInterval(function() {
     const s = fs.createReadStream(emptyTxt);