Rule fix: Fix fixer for no-extend to ignore single argument mode (#322)

Author: edg2s

docs/rules/no-extend.md

@@ -21,6 +21,7 @@ $.extend( true, {}, foo );
 extend();
 myMethod.extend();
 myMethod.extend;
+$.extend( { myUtil: fn } );
 ```
 
 ❌ Examples of **incorrect** code with `[{"allowDeep":true}]` options:

src/rules/no-extend.js

@@ -30,10 +30,14 @@ module.exports = {
 			const name = node.callee.property.name;
 			if (
 				name !== 'extend' ||
-					!utils.isjQueryConstructor( context, node.callee.object.name )
+				!utils.isjQueryConstructor( context, node.callee.object.name )
 			) {
 				return;
 			}
+			if ( node.arguments.length === 1 ) {
+				// $.extend with one argument merges the object onto the jQuery namespace
+				return;
+			}
 			const allowDeep = context.options[ 0 ] && context.options[ 0 ].allowDeep;
 			const isDeep = node.arguments[ 0 ] && node.arguments[ 0 ].value === true;
 			if ( allowDeep && isDeep ) {

tests/rules/no-extend.js

@@ -14,7 +14,8 @@ ruleTester.run( 'no-extend', rule, {
 		{
 			code: '$.extend(true, {}, foo)',
 			options: [ { allowDeep: true } ]
-		}
+		},
+		'$.extend({myUtil:fn})'
 	],
 	invalid: [
 		{