Fix handling of backslash escapes in format strings

marijnh · marijnh · commit 987290e061e0 · 2023-05-27T22:13:23.000+02:00
FIX: Fix a bug that broke handling of escaped quotes in format strings. Closes codemirror/dev#1166
diff --git a/src/tokens.js b/src/tokens.js
@@ -13,7 +13,7 @@ import {
 } from "./parser.terms.js"
 
 const newline = 10, carriageReturn = 13, space = 32, tab = 9, hash = 35, parenOpen = 40, dot = 46,
-      braceOpen = 123, singleQuote = 39, doubleQuote = 34
+      braceOpen = 123, singleQuote = 39, doubleQuote = 34, backslash = 92
 
 const bracketed = new Set([
   ParenthesizedExpression, TupleExpression, ComprehensionExpression, importList, ArgList, ParamList,
@@ -126,7 +126,7 @@ function formatString(quote, len, content, brace, end) {
           }
           break
         }
-      } else if (input.next == "\\") {
+      } else if (input.next == backslash) {
         input.advance()
         if (input.next >= 0) input.advance()
       } else if (input.next == quote && (len == 1 || input.peek(1) == quote && input.peek(2) == quote)) {
diff --git a/test/expression.txt b/test/expression.txt
@@ -45,8 +45,8 @@ Script(ExpressionStatement(CallExpression(VariableName, ArgList(ContinuedString(
 
 # Format strings
 
-f'hello{22} abc {{ }} {d-1}'
-f"double {quoted !s}"
+f'hello{22} abc\' {{ }} {d-1}'
+f"double\" {quoted !s}"
 f"""big long format
   {string :foo}"""
 f'''well {{ \x }} {2 :{bar}}'''
@@ -206,6 +206,7 @@ Script(AssignStatement(VariableName, AssignOp, ConditionalExpression(Number, if,
 2 ** 3 ** 2
 
 ==>
+
 Script(ExpressionStatement(BinaryExpression(
   Number,ArithOp("**"),
   BinaryExpression(Number,ArithOp("**"),Number))))
