Fix double quote escaping before new line

lib/JSON2CSVBase.js

@@ -181,7 +181,7 @@ class JSON2CSVBase {
     //a backslash, and it's not at the end of the stringifiedValue.
     stringifiedValue = stringifiedValue
       .replace(/^"(.*)"$/, this.opts.quote + '$1' + this.opts.quote)
-      .replace(/(\\")(?=.)/g, this.opts.doubleQuote)
+      .replace(/(\\")(?!$)/g, this.opts.doubleQuote)
       .replace(/\\\\/g, '\\');
 
     if (this.opts.excelStrings && typeof value === 'string') {

test/JSON2CSVParser.js

@@ -425,6 +425,18 @@ module.exports = (testRunner, jsonFixtures, csvFixtures) => {
     t.end();
   });
 
+  testRunner.add('should escape quotes before new line with value in \'doubleQuote\'', (t) => {
+    const opts = {
+      fields: ['a string']
+    };
+
+    const parser = new Json2csvParser(opts);
+    const csv = parser.parse(jsonFixtures.backslashBeforeNewLine);
+
+    t.equal(csv, csvFixtures.backslashBeforeNewLine);
+    t.end();
+  });
+
   // Delimiter
 
   testRunner.add('should use a custom delimiter when \'delimiter\' property is defined', (t) => {

test/JSON2CSVTransform.js

@@ -612,6 +612,24 @@ module.exports = (testRunner, jsonFixtures, csvFixtures) => {
       .on('error', err => t.notOk(true, err.message));
   });
 
+  testRunner.add('should escape quotes before new line with value in \'doubleQuote\'', (t) => {
+    const opts = {
+      fields: ['a string']
+    };
+
+    const transform = new Json2csvTransform(opts);
+    const processor = jsonFixtures.backslashBeforeNewLine().pipe(transform);
+
+    let csv = '';
+    processor
+      .on('data', chunk => (csv += chunk.toString()))
+      .on('end', () => {
+        t.equal(csv, csvFixtures.backslashBeforeNewLine);
+        t.end();
+      })
+      .on('error', err => t.notOk(true, err.message));
+  });
+
   // Delimiter
 
   testRunner.add('should use a custom delimiter when \'delimiter\' property is defined', (t) => {

test/fixtures/csv/backslashBeforeNewLine.csv

@@ -0,0 +1,6 @@
+"a string"
+"with a description"
+"with a description and ""
+quotes and backslash\"
+"with a description and ""
+quotes and backslash\\"

test/fixtures/json/backslashBeforeNewLine.json

@@ -0,0 +1,5 @@
+[
+  {"a string": "with a description"},
+  {"a string": "with a description and \"\nquotes and backslash\\"},
+  {"a string": "with a description and \"\nquotes and backslash\\\\"}
+]