From 292e8f8b210593ff0d0b3c36e9c3a98d04e46980 Mon Sep 17 00:00:00 2001
From: Toru Nagashima <star.ctor@gmail.com>
Date: Sun, 30 Oct 2016 21:36:21 +0900
Subject: [PATCH] Fix: false positive of `no-unsupported-features` about code
 point escapes.

---
 lib/rules/no-unsupported-features.js       | 25 +++++++++++++++++++---
 tests/lib/rules/no-unsupported-features.js |  6 +++++-
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/lib/rules/no-unsupported-features.js b/lib/rules/no-unsupported-features.js
index f44bde35..c1bb755c 100644
--- a/lib/rules/no-unsupported-features.js
+++ b/lib/rules/no-unsupported-features.js
@@ -25,7 +25,7 @@ var CLASS_TYPE = /^Class(?:Declaration|Expression)$/
 var DESTRUCTURING_PARENT_TYPE = /^(?:Function(?:Declaration|Expression)|ArrowFunctionExpression|AssignmentExpression|VariableDeclarator)$/
 var BINARY_NUMBER = /^0[bB]/
 var OCTAL_NUMBER = /^0[oO]/
-var UNICODE_ESC = /\\u\{.+?\}/
+var UNICODE_ESC = /(\\+)u\{[0-9a-fA-F]+?\}/g
 var GET_OR_SET = /^(?:g|s)et$/
 var NEW_BUILTIN_TYPES = [
     "Int8Array", "Uint8Array", "Uint8ClampedArray", "Int16Array", "Uint16Array",
@@ -230,6 +230,25 @@ function getIdentifierName(node) {
     return node.name
 }
 
+/**
+ * Checks whether the given string has `\u{90ABCDEF}`-like escapes.
+ *
+ * @param {string} raw - The string to check.
+ * @returns {boolean} `true` if the string has Unicode code point escapes.
+ */
+function hasUnicodeCodePointEscape(raw) {
+    var match = null
+
+    UNICODE_ESC.lastIndex = 0
+    while ((match = UNICODE_ESC.exec(raw)) != null) {
+        if (match[1].length % 2 === 1) {
+            return true
+        }
+    }
+
+    return false
+}
+
 //------------------------------------------------------------------------------
 // Rule Definition
 //------------------------------------------------------------------------------
@@ -447,7 +466,7 @@ module.exports = function(context) {
 
         "Identifier": function(node) {
             var raw = sourceCode.getText(node)
-            if (UNICODE_ESC.test(raw)) {
+            if (hasUnicodeCodePointEscape(raw)) {
                 report(node, "unicodeCodePointEscapes")
             }
         },
@@ -462,7 +481,7 @@ module.exports = function(context) {
                 }
             }
             else if (typeof node.value === "string") {
-                if (UNICODE_ESC.test(node.raw)) {
+                if (hasUnicodeCodePointEscape(node.raw)) {
                     report(node, "unicodeCodePointEscapes")
                 }
             }
diff --git a/tests/lib/rules/no-unsupported-features.js b/tests/lib/rules/no-unsupported-features.js
index cc9d9daf..e98d5007 100644
--- a/tests/lib/rules/no-unsupported-features.js
+++ b/tests/lib/rules/no-unsupported-features.js
@@ -203,7 +203,7 @@ ruleTester.run("no-unsupported-features", rule, [
     {
         keys: ["unicodeCodePointEscapes", "syntax"],
         name: "Unicode Code Point Escapes",
-        code: "var \\u{102C0} = { \\u{102C0} : '\\u{1d306}' };", // eslint-disable-line node/no-unsupported-features
+        code: "var \\u{102C0} = { \\u{102C0} : '\\u{1d306}' };", //eslint-disable-line node/no-unsupported-features
         errors: 3,
         supported: 4,
     },
@@ -945,6 +945,10 @@ ruleTester.run("no-unsupported-features", rule, [
             code: "var a = () => 1",
             env: {es6: true},
         },
+        {
+            code: "'\\\\u{0123}'", //eslint-disable-line node/no-unsupported-features
+            env: {es6: true},
+        },
     ],
     invalid: [
         {