test: replace function with arrow function

PR-URL: #17305
Reviewed-By: Yosuke Furukawa <yosuke.furukawa@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-http.js

@@ -72,41 +72,41 @@ server.on('listening', function() {
       Cookie: [ 'foo=bar', 'bar=baz', 'baz=quux' ]
     },
     agent: agent
-  }, common.mustCall(function(res) {
+  }, common.mustCall((res) => {
     const cookieHeaders = req._header.match(/^Cookie: .+$/img);
     assert.deepStrictEqual(cookieHeaders,
                            ['Cookie: foo=bar; bar=baz; baz=quux']);
     assert.strictEqual(res.statusCode, 200);
     let body = '';
     res.setEncoding('utf8');
-    res.on('data', function(chunk) { body += chunk; });
-    res.on('end', common.mustCall(function() {
+    res.on('data', (chunk) => { body += chunk; });
+    res.on('end', common.mustCall(() => {
       assert.strictEqual(body, 'The path was /hello');
     }));
   }));
 
-  setTimeout(common.mustCall(function() {
+  setTimeout(common.mustCall(() => {
     const req = http.request({
       port: server.address().port,
       method: 'PUT',
       path: '/there',
       agent: agent
-    }, common.mustCall(function(res) {
+    }, common.mustCall((res) => {
       const cookieHeaders = req._header.match(/^Cookie: .+$/img);
       assert.deepStrictEqual(cookieHeaders, ['Cookie: node=awesome; ta=da']);
       assert.strictEqual(res.statusCode, 200);
       let body = '';
       res.setEncoding('utf8');
-      res.on('data', function(chunk) { body += chunk; });
-      res.on('end', common.mustCall(function() {
+      res.on('data', (chunk) => { body += chunk; });
+      res.on('end', common.mustCall(() => {
         assert.strictEqual(body, 'The path was /there');
       }));
     }));
     req.setHeader('Cookie', ['node=awesome', 'ta=da']);
     req.end();
   }), 1);
 
-  setTimeout(common.mustCall(function() {
+  setTimeout(common.mustCall(() => {
     const req = http.request({
       port: server.address().port,
       method: 'POST',
@@ -115,7 +115,7 @@ server.on('listening', function() {
                  ['Cookie', 'def=456'],
                  ['Cookie', 'ghi=789'] ],
       agent: agent
-    }, common.mustCall(function(res) {
+    }, common.mustCall((res) => {
       const cookieHeaders = req._header.match(/^Cookie: .+$/img);
       assert.deepStrictEqual(cookieHeaders,
                              ['Cookie: abc=123',
@@ -124,8 +124,8 @@ server.on('listening', function() {
       assert.strictEqual(res.statusCode, 200);
       let body = '';
       res.setEncoding('utf8');
-      res.on('data', function(chunk) { body += chunk; });
-      res.on('end', common.mustCall(function() {
+      res.on('data', (chunk) => { body += chunk; });
+      res.on('end', common.mustCall(() => {
         assert.strictEqual(body, 'The path was /world');
       }));
     }));