From eea03801e05ec5de4e66da1d0438c07d5a77d568 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Wed, 7 Sep 2016 06:34:28 -0700
Subject: [PATCH] When emitting react code, replace HTML numeric entities with
 their encoded characters

---
 src/compiler/transformers/jsx.ts                 | 16 +++++++++++-----
 .../baselines/reference/tsxReactEmitEntities.js  |  2 ++
 .../reference/tsxReactEmitEntities.symbols       |  4 ++++
 .../reference/tsxReactEmitEntities.types         |  5 +++++
 .../conformance/jsx/tsxReactEmitEntities.tsx     |  1 +
 5 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/compiler/transformers/jsx.ts b/src/compiler/transformers/jsx.ts
index 4bc523a262..8982c0faf2 100644
--- a/src/compiler/transformers/jsx.ts
+++ b/src/compiler/transformers/jsx.ts
@@ -210,15 +210,21 @@ namespace ts {
         }
 
         /**
-         * Decodes JSX entities.
+         * Replace entities like "&nbsp;", "&#123;", and "&#xDEADBEEF;" with the characters they encode.
+         * See https://en.wikipedia.org/wiki/List_of_XML_and_HTML_character_entity_references
          */
         function decodeEntities(text: string) {
-            return text.replace(/&(\w+);/g, function(s: any, m: string) {
-                if (entities[m] !== undefined) {
-                    return String.fromCharCode(entities[m]);
+            return text.replace(/&((#((\d+)|x([\da-fA-F]+)))|(\w+));/g, (match, _all, _number, _digits, decimal, hex, word) => {
+                if (decimal) {
+                    return String.fromCharCode(parseInt(decimal, 10));
+                }
+                else if (hex) {
+                    return String.fromCharCode(parseInt(hex, 16));
                 }
                 else {
-                    return s;
+                    const ch = entities[word];
+                    // If this is not a valid entity, then just use `match` (replace it with itself, i.e. don't replace)
+                    return ch ? String.fromCharCode(ch) : match;
                 }
             });
         }
diff --git a/tests/baselines/reference/tsxReactEmitEntities.js b/tests/baselines/reference/tsxReactEmitEntities.js
index 2a5c1ec496..8fbf59a376 100644
--- a/tests/baselines/reference/tsxReactEmitEntities.js
+++ b/tests/baselines/reference/tsxReactEmitEntities.js
@@ -9,8 +9,10 @@ declare var React: any;
 
 <div>Dot goes here: &middot; &notAnEntity; </div>;
 <div>Be careful of &quot;-ed strings!</div>;
+<div>&#0123;&#123;braces&#x7d;&#x7D;</div>;
 
 
 //// [file.js]
 React.createElement("div", null, "Dot goes here: \u00B7 &notAnEntity; ");
 React.createElement("div", null, "Be careful of \"-ed strings!");
+React.createElement("div", null, "{{braces}}");
diff --git a/tests/baselines/reference/tsxReactEmitEntities.symbols b/tests/baselines/reference/tsxReactEmitEntities.symbols
index 5a0274029e..873830773b 100644
--- a/tests/baselines/reference/tsxReactEmitEntities.symbols
+++ b/tests/baselines/reference/tsxReactEmitEntities.symbols
@@ -23,3 +23,7 @@ declare var React: any;
 >div : Symbol(JSX.IntrinsicElements, Decl(file.tsx, 1, 22))
 >div : Symbol(JSX.IntrinsicElements, Decl(file.tsx, 1, 22))
 
+<div>&#0123;&#123;braces&#x7d;&#x7D;</div>;
+>div : Symbol(JSX.IntrinsicElements, Decl(file.tsx, 1, 22))
+>div : Symbol(JSX.IntrinsicElements, Decl(file.tsx, 1, 22))
+
diff --git a/tests/baselines/reference/tsxReactEmitEntities.types b/tests/baselines/reference/tsxReactEmitEntities.types
index 111653ea14..7fe68df5f4 100644
--- a/tests/baselines/reference/tsxReactEmitEntities.types
+++ b/tests/baselines/reference/tsxReactEmitEntities.types
@@ -25,3 +25,8 @@ declare var React: any;
 >div : any
 >div : any
 
+<div>&#0123;&#123;braces&#x7d;&#x7D;</div>;
+><div>&#0123;&#123;braces&#x7d;&#x7D;</div> : JSX.Element
+>div : any
+>div : any
+
diff --git a/tests/cases/conformance/jsx/tsxReactEmitEntities.tsx b/tests/cases/conformance/jsx/tsxReactEmitEntities.tsx
index 4726008d6b..8af5bf206e 100644
--- a/tests/cases/conformance/jsx/tsxReactEmitEntities.tsx
+++ b/tests/cases/conformance/jsx/tsxReactEmitEntities.tsx
@@ -10,3 +10,4 @@ declare var React: any;
 
 <div>Dot goes here: &middot; &notAnEntity; </div>;
 <div>Be careful of &quot;-ed strings!</div>;
+<div>&#0123;&#123;braces&#x7d;&#x7D;</div>;