From 8aacbf0bff9955f1ff537d07df370d4146a986f8 Mon Sep 17 00:00:00 2001
From: Andrew Branch <andrew@wheream.io>
Date: Wed, 1 Apr 2020 14:15:18 -0700
Subject: [PATCH 1/3] Add failing test

---
 ...tStringOrTemplateLiteral_escapedBackslashes.ts | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 tests/cases/fourslash/refactorConvertStringOrTemplateLiteral_escapedBackslashes.ts

diff --git a/tests/cases/fourslash/refactorConvertStringOrTemplateLiteral_escapedBackslashes.ts b/tests/cases/fourslash/refactorConvertStringOrTemplateLiteral_escapedBackslashes.ts
new file mode 100644
index 0000000000000..6025107ff0321
--- /dev/null
+++ b/tests/cases/fourslash/refactorConvertStringOrTemplateLiteral_escapedBackslashes.ts
@@ -0,0 +1,15 @@
+/// <reference path='fourslash.ts' />
+
+//// console.log(/*0*/"\\[[" + text + "](" + link + ")\\]"/*1*/)
+
+goTo.select("0", "1");
+edit.applyRefactor({
+    refactorName: "Convert to template string",
+    actionName: "Convert to template string",
+    actionDescription: ts.Diagnostics.Convert_to_template_string.message,
+    // Four backslashes here
+    //   = two backslashes in the expected file content
+    //   = one backslash in the string data sent to console.log
+    //     (which is the same as what the user started with)
+    newContent: 'console.log(`\\\\[[${text}](${link})\\\\]`)',
+});

From f7e3445735687dd3210b5072bc08012a46ac1cf5 Mon Sep 17 00:00:00 2001
From: Andrew Branch <andrew@wheream.io>
Date: Wed, 1 Apr 2020 16:29:36 -0700
Subject: [PATCH 2/3] Remove extraneous string escape

---
 src/compiler/utilities.ts                                | 7 ++++---
 src/services/refactors/convertStringOrTemplateLiteral.ts | 1 -
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 2c6f8b70a34b1..6be4956aef3b8 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -3441,7 +3441,7 @@ namespace ts {
     const doubleQuoteEscapedCharsRegExp = /[\\\"\u0000-\u001f\t\v\f\b\r\n\u2028\u2029\u0085]/g;
     const singleQuoteEscapedCharsRegExp = /[\\\'\u0000-\u001f\t\v\f\b\r\n\u2028\u2029\u0085]/g;
     // Template strings should be preserved as much as possible
-    const backtickQuoteEscapedCharsRegExp = /[\\\`]/g;
+    const backtickQuoteEscapedCharsRegExp = /[\\`]/g;
     const escapedCharsMap = createMapFromTemplate({
         "\t": "\\t",
         "\v": "\\v",
@@ -3465,8 +3465,9 @@ namespace ts {
     }
 
     function getReplacement(c: string, offset: number, input: string) {
-        if (c.charCodeAt(0) === CharacterCodes.nullCharacter) {
-            const lookAhead = input.charCodeAt(offset + c.length);
+        const charCode = c.charCodeAt(0);
+        if (charCode === CharacterCodes.nullCharacter) {
+            const lookAhead = input.charCodeAt(offset + 1);
             if (lookAhead >= CharacterCodes._0 && lookAhead <= CharacterCodes._9) {
                 // If the null character is followed by digits, print as a hex escape to prevent the result from parsing as an octal (which is forbidden in strict mode)
                 return "\\x00";
diff --git a/src/services/refactors/convertStringOrTemplateLiteral.ts b/src/services/refactors/convertStringOrTemplateLiteral.ts
index 58a62a77d7e3c..bfa398109e59a 100644
--- a/src/services/refactors/convertStringOrTemplateLiteral.ts
+++ b/src/services/refactors/convertStringOrTemplateLiteral.ts
@@ -134,7 +134,6 @@ namespace ts.refactor.convertStringOrTemplateLiteral {
             index++;
         }
 
-        text = escapeString(text);
         return [index, text, indexes];
     }
 

From b9c86af8e6a6e27a0fceed06fdf2dbd1d402c97b Mon Sep 17 00:00:00 2001
From: Andrew Branch <andrewbranch@users.noreply.github.com>
Date: Wed, 8 Apr 2020 16:09:33 -0800
Subject: [PATCH 3/3] Revert unnecessary change

---
 src/compiler/utilities.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 6be4956aef3b8..9b302a9e5222b 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -3465,9 +3465,8 @@ namespace ts {
     }
 
     function getReplacement(c: string, offset: number, input: string) {
-        const charCode = c.charCodeAt(0);
-        if (charCode === CharacterCodes.nullCharacter) {
-            const lookAhead = input.charCodeAt(offset + 1);
+        if (c.charCodeAt(0) === CharacterCodes.nullCharacter) {
+            const lookAhead = input.charCodeAt(offset + c.length);
             if (lookAhead >= CharacterCodes._0 && lookAhead <= CharacterCodes._9) {
                 // If the null character is followed by digits, print as a hex escape to prevent the result from parsing as an octal (which is forbidden in strict mode)
                 return "\\x00";