Escape JSON special chars. Fixes #44

src/writers/JSONCBWriter.ts

@@ -150,7 +150,7 @@ export class JSONCBWriter extends BaseCBWriter<JSONCBWriterOptions> {
    * Produces a JSON value string delimited with double quotes.
    */
   private _val(val: string): string {
-    return "\"" + val + "\""
+    return JSON.stringify(val)
   }
 
 }

src/writers/JSONWriter.ts

@@ -96,7 +96,7 @@ export class JSONWriter extends BaseWriter<JSONWriterOptions, string> {
       }
       markup += '}'
     } else {
-      markup += '"' + obj + '"'
+      markup += JSON.stringify(obj)
     }
     return markup
   }

test/issues/issue-044.test.ts

@@ -0,0 +1,24 @@
+import $$ from '../TestHelpers'
+import { select } from "xpath"
+
+describe('Replicate issue', () => {
+
+  // https://github.com/oozcitak/xmlbuilder2/issues/44
+  test('#44 - Converting XML to JSON does not escape invalid string characters', () => {
+    const jsonStr = $$.convert('<a>b\nc</a>', { format: 'json' })
+    expect(jsonStr).toBe(`{"a":"b\\nc"}`)
+
+    const invalidChars = Array.from(Array(0x20), (_, i) => {
+      return String.fromCharCode(i);
+    }).concat('"', '\\')
+
+    const xml = $$.convert(
+      `<a>${invalidChars.map((c) => `<b>_${c}_</b>`).join('\n')}</a>`
+    )
+    const json = $$.convert(xml, { format: 'json' })
+    expect(() => JSON.parse(json)).not.toThrow()
+
+    const obj = $$.convert(xml, { format: 'object' })
+    expect(JSON.stringify(obj)).toBe(json)
+  })
+})