Refactor prefer-node-append to use selector (#509)

Author: fisker

rules/prefer-node-append.js

@@ -1,23 +1,27 @@
 'use strict';
 const getDocumentationUrl = require('./utils/get-documentation-url');
 const isValueNotUsable = require('./utils/is-value-not-usable');
+const methodSelector = require('./utils/method-selector');
 
-const getMethodName = memberExpression => memberExpression.property.name;
+const message = 'Prefer `Node#append()` over `Node#appendChild()`.';
+const selector = methodSelector({
+	name: 'appendChild',
+	length: 1
+});
 
 const create = context => {
 	return {
-		CallExpression(node) {
-			const {callee} = node;
+		[selector](node) {
+			// TODO: exclude those cases parent/child impossible to be `Node`
+			const fix = isValueNotUsable(node) ?
+				fixer => fixer.replaceText(node.callee.property, 'append') :
+				undefined;
 
-			if (callee.type === 'MemberExpression' && getMethodName(callee) === 'appendChild') {
-				const fix = isValueNotUsable(node) ? fixer => fixer.replaceText(callee.property, 'append') : undefined;
-
-				context.report({
-					node,
-					message: 'Prefer `Node#append()` over `Node#appendChild()`.',
-					fix
-				});
-			}
+			context.report({
+				node,
+				message,
+				fix
+			});
 		}
 	};
 };

rules/utils/method-selector.js

@@ -0,0 +1,25 @@
+'use strict';
+
+module.exports = options => {
+	const {name, length, allowSpreadElement} = {
+		allowSpreadElement: false,
+		...options
+	};
+
+	return [
+		'CallExpression',
+		'[callee.type="MemberExpression"]',
+		'[callee.computed=false]',
+		'[callee.property.type="Identifier"]',
+		`[callee.property.name="${name}"]`,
+		`[arguments.length=${length}]`,
+		...(
+			allowSpreadElement ?
+				[] :
+				Array.from(
+					{length},
+					(_, index) => `[arguments.${index}.type!="SpreadElement"]`
+				)
+		)
+	].join('');
+};

test/prefer-node-append.js

@@ -15,10 +15,22 @@ const error = {
 
 ruleTester.run('prefer-node-append', rule, {
 	valid: [
+		// Already using `append`
 		'parent.append(child);',
-		'document.body.append(child, \'text\');',
-		'node.append()',
-		'node.append(null)'
+		// Not `CallExpression`
+		'new parent.appendChild(child);',
+		// Not `MemberExpression`
+		'appendChild(child);',
+		// `callee.property` is not a `Identifier`
+		'parent[\'appendChild\'](child);',
+		// Computed
+		'parent[appendChild](child);',
+		// Not `appendChild`
+		'parent.foo(child);',
+		// More or less argument(s)
+		'parent.appendChild(one, two);',
+		'parent.appendChild();',
+		'parent.appendChild(...argumentsArray)'
 	],
 	invalid: [
 		{
@@ -31,11 +43,6 @@ ruleTester.run('prefer-node-append', rule, {
 			output: 'document.body.append(child);',
 			errors: [error]
 		},
-		{
-			code: 'node.appendChild()',
-			output: 'node.append()',
-			errors: [error]
-		},
 		{
 			code: 'node.appendChild(null)',
 			output: 'node.append(null)',