From 747afaa59e20b57a561404306cf4dc83dd1c7798 Mon Sep 17 00:00:00 2001
From: Juriy Zaytsev <kangax@fb.com>
Date: Fri, 4 Nov 2016 14:40:26 -0700
Subject: [PATCH 1/2] Escape newline in regex optimization

---
 .../__tests__/transform-regexp-constructors-test.js        | 6 ++++++
 .../src/index.js                                           | 7 ++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-regexp-constructors/__tests__/transform-regexp-constructors-test.js b/packages/babel-plugin-transform-regexp-constructors/__tests__/transform-regexp-constructors-test.js
index 9f8a64b81..e3f35382e 100644
--- a/packages/babel-plugin-transform-regexp-constructors/__tests__/transform-regexp-constructors-test.js
+++ b/packages/babel-plugin-transform-regexp-constructors/__tests__/transform-regexp-constructors-test.js
@@ -59,4 +59,10 @@ const flags = "g";
 const ret = /ab+c\\wd/g;`;
     expect(transform(source)).toBe(expected);
   });
+
+  it("should work with newlines", () => {
+    const source = "var x = new RegExp('\\r\\n\\n')";
+    const expected = "var x = /\\r\\n\\n/;";
+    expect(transform(source)).toBe(expected);
+  });
 });
diff --git a/packages/babel-plugin-transform-regexp-constructors/src/index.js b/packages/babel-plugin-transform-regexp-constructors/src/index.js
index 469918adf..6cd66dc8d 100644
--- a/packages/babel-plugin-transform-regexp-constructors/src/index.js
+++ b/packages/babel-plugin-transform-regexp-constructors/src/index.js
@@ -14,13 +14,18 @@ module.exports = function({ types: t }) {
             typeof a.value === "string")) {
           return;
         }
-        const pattern = (evaluatedArgs.length >= 1 &&
+        let pattern = (evaluatedArgs.length >= 1 &&
                           evaluatedArgs[0].value !== "") ?
                         evaluatedArgs[0].value :
                         "(?:)";
         const flags = evaluatedArgs.length >= 2 ?
                       evaluatedArgs[1].value :
                       "";
+
+        pattern = pattern
+          .replace(/\n/g, '\\n')
+          .replace(/\r/g, '\\r');
+
         path.replaceWith(t.regExpLiteral(pattern, flags));
       }
     },

From 9e63cce129468a440a717e95e7c46728b54895ce Mon Sep 17 00:00:00 2001
From: Juriy Zaytsev <kangax@fb.com>
Date: Fri, 4 Nov 2016 15:22:55 -0700
Subject: [PATCH 2/2] Add slash

---
 .../__tests__/transform-regexp-constructors-test.js         | 6 +++---
 .../babel-plugin-transform-regexp-constructors/src/index.js | 3 ++-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/packages/babel-plugin-transform-regexp-constructors/__tests__/transform-regexp-constructors-test.js b/packages/babel-plugin-transform-regexp-constructors/__tests__/transform-regexp-constructors-test.js
index e3f35382e..eb0744723 100644
--- a/packages/babel-plugin-transform-regexp-constructors/__tests__/transform-regexp-constructors-test.js
+++ b/packages/babel-plugin-transform-regexp-constructors/__tests__/transform-regexp-constructors-test.js
@@ -60,9 +60,9 @@ const ret = /ab+c\\wd/g;`;
     expect(transform(source)).toBe(expected);
   });
 
-  it("should work with newlines", () => {
-    const source = "var x = new RegExp('\\r\\n\\n')";
-    const expected = "var x = /\\r\\n\\n/;";
+  it("should escape invalid chars", () => {
+    const source = "var x = new RegExp('\\r\\n\\n/x/')";
+    const expected = "var x = /\\r\\n\\n\\/x\\//;";
     expect(transform(source)).toBe(expected);
   });
 });
diff --git a/packages/babel-plugin-transform-regexp-constructors/src/index.js b/packages/babel-plugin-transform-regexp-constructors/src/index.js
index 6cd66dc8d..29e62714a 100644
--- a/packages/babel-plugin-transform-regexp-constructors/src/index.js
+++ b/packages/babel-plugin-transform-regexp-constructors/src/index.js
@@ -24,7 +24,8 @@ module.exports = function({ types: t }) {
 
         pattern = pattern
           .replace(/\n/g, '\\n')
-          .replace(/\r/g, '\\r');
+          .replace(/\r/g, '\\r')
+          .replace(/\//g, '\\/');
 
         path.replaceWith(t.regExpLiteral(pattern, flags));
       }