From e10eebab4abd193dee697c4de7fb2d95bbab2d8c Mon Sep 17 00:00:00 2001
From: Milos Djermanovic <milos.djermanovic@gmail.com>
Date: Sat, 31 Aug 2019 16:51:14 +0200
Subject: [PATCH] Fix: quotes autofix produces syntax error with octal escape
 sequences (#12118)

---
 lib/rules/quotes.js       |  6 +++
 tests/lib/rules/quotes.js | 90 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)

diff --git a/lib/rules/quotes.js b/lib/rules/quotes.js
index 28b20af29f4..5f260e55f0a 100644
--- a/lib/rules/quotes.js
+++ b/lib/rules/quotes.js
@@ -279,6 +279,12 @@ module.exports = {
                                 description: settings.description
                             },
                             fix(fixer) {
+                                if (quoteOption === "backtick" && astUtils.hasOctalEscapeSequence(rawVal)) {
+
+                                    // An octal escape sequence in a template literal would produce syntax error, even in non-strict mode.
+                                    return null;
+                                }
+
                                 return fixer.replaceText(node, settings.convert(node.raw));
                             }
                         });
diff --git a/tests/lib/rules/quotes.js b/tests/lib/rules/quotes.js
index 3245c745476..5a12ad0fbf3 100644
--- a/tests/lib/rules/quotes.js
+++ b/tests/lib/rules/quotes.js
@@ -328,6 +328,96 @@ ruleTester.run("quotes", rule, {
             output: "\"\"``",
             parserOptions: { ecmaVersion: 6 },
             errors: [{ message: "Strings must use doublequote.", type: "TemplateLiteral", line: 1, column: 1 }]
+        },
+
+        // Strings containing octal escape sequences. Don't autofix to backticks.
+        {
+            code: "var foo = \"\\1\"",
+            output: "var foo = '\\1'",
+            options: ["single"],
+            errors: [
+                { message: "Strings must use singlequote.", type: "Literal" }
+            ]
+        },
+        {
+            code: "var foo = '\\1'",
+            output: "var foo = \"\\1\"",
+            options: ["double"],
+            errors: [
+                { message: "Strings must use doublequote.", type: "Literal" }
+            ]
+        },
+        {
+            code: "var notoctal = '\\0'",
+            output: "var notoctal = `\\0`",
+            options: ["backtick"],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                { message: "Strings must use backtick.", type: "Literal" }
+            ]
+        },
+        {
+            code: "var foo = '\\1'",
+            output: null,
+            options: ["backtick"],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                { message: "Strings must use backtick.", type: "Literal" }
+            ]
+        },
+        {
+            code: "var foo = \"\\1\"",
+            output: null,
+            options: ["backtick"],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                { message: "Strings must use backtick.", type: "Literal" }
+            ]
+        },
+        {
+            code: "var foo = '\\01'",
+            output: null,
+            options: ["backtick"],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                { message: "Strings must use backtick.", type: "Literal" }
+            ]
+        },
+        {
+            code: "var foo = '\\0\\1'",
+            output: null,
+            options: ["backtick"],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                { message: "Strings must use backtick.", type: "Literal" }
+            ]
+        },
+        {
+            code: "var foo = '\\08'",
+            output: null,
+            options: ["backtick"],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                { message: "Strings must use backtick.", type: "Literal" }
+            ]
+        },
+        {
+            code: "var foo = 'prefix \\33'",
+            output: null,
+            options: ["backtick"],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                { message: "Strings must use backtick.", type: "Literal" }
+            ]
+        },
+        {
+            code: "var foo = 'prefix \\75 sufix'",
+            output: null,
+            options: ["backtick"],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                { message: "Strings must use backtick.", type: "Literal" }
+            ]
         }
     ]
 });