Fix prefer-negative-index crash on not enough arguments (#564)

sindresorhus · Feb 16, 2020 · 50e038c · 50e038c
1 parent 027fb84
commit 50e038c
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Showing 2 changed files with 5 additions and 2 deletions.
diff --git a/rules/prefer-negative-index.js b/rules/prefer-negative-index.js
@@ -241,7 +241,7 @@ function parse(node) {
 
 		if (isApply) {
 			const [, secondArgument] = originalArguments;
-			if (secondArgument.type !== 'ArrayExpression') {
+			if (!secondArgument || secondArgument.type !== 'ArrayExpression') {
 				return;
 			}
 

diff --git a/test/prefer-negative-index.js b/test/prefer-negative-index.js
@@ -62,7 +62,10 @@ ruleTester.run('prefer-negative-index', rule, {
 		// Foo[bar++]
 		'foo[bar++].slice(foo[bar++].length - 1)',
 		// Foo['bar'] & foo["bar"]
-		'foo[\'bar\'].slice(foo["bar"].length - 1)'
+		'foo[\'bar\'].slice(foo["bar"].length - 1)',
+		// Should not crash
+		// https://github.com/gatsbyjs/gatsby/blob/e720d8efe58eba0f6fae9f26ec8879128967d0b5/packages/gatsby/src/bootstrap/log-line-function.js#L9
+		'function foo() {return [].slice.apply(arguments);}'
 	],
 	invalid: [
 		// Docs example (1)