tools: auto fix custom eslint rule for buffer-constructor.js

This implements a fixer method to fix the usage of Deprecated Buffer() constructor.

Also adds some more test cases to the eslint rule.

Refs: nodejs#16636

test/parallel/test-eslint-buffer-constructor.js

@@ -11,16 +11,29 @@ const message = 'Use of the Buffer() constructor has been deprecated. ' +
 
 new RuleTester().run('buffer-constructor', rule, {
   valid: [
-    'Buffer.from(foo)'
+    'Buffer.from(foo)',
+    'Buffer.from(foo, bar)',
+    'Buffer.alloc(foo)',
+    'Buffer.alloc(foo, bar)',
+    'Buffer.allocUnsafe(foo)',
+    'Buffer.allocUnsafe(foo, bar)'
   ],
   invalid: [
     {
       code: 'Buffer(foo)',
       errors: [{ message }]
     },
+    {
+      code: 'Buffer(foo, bar)',
+      errors: [{ message }]
+    },
     {
       code: 'new Buffer(foo)',
       errors: [{ message }]
+    },
+    {
+      code: 'new Buffer(foo, bar)',
+      errors: [{ message }]
     }
   ]
 });

tools/eslint-rules/buffer-constructor.js

@@ -13,7 +13,22 @@ const msg = 'Use of the Buffer() constructor has been deprecated. ' +
 
 function test(context, node) {
   if (node.callee.name === 'Buffer') {
-    context.report(node, msg);
+    const sourceCode = context.getSourceCode();
+    const argumentList = [];
+    node.arguments.forEach((argumentNode) => {
+      argumentList.push(sourceCode.getText(argumentNode));
+    });
+
+    context.report({
+      node,
+      message: msg,
+      fix: (fixer) => {
+        return fixer.replaceText(
+          node,
+          `Buffer.from(${argumentList.join(', ')})`
+        );
+      }
+    });
   }
 }