Add logic to wrap booleans when specified.

In order to support the use case of keeping Booleans as String values
that can easily be converted back with csv2json, this commit adds a new
option `wrapBooleans` which will allow users a way to make this possible

Fixes #188

README.md

@@ -138,6 +138,8 @@ Looking for examples? Check out the Wiki: [json-2-csv Wiki](https://github.com/m
   * `useLocaleFormat` - Boolean - Should values be converted to a locale specific string?
     * Default: `false`
     * Note: If selected, values will be converted using `toLocaleString()` rather than `toString()`
+  * `wrapBooleans` - Boolean - Should boolean values be wrapped in wrap delimiters to prevent Excel from converting them to Excel's TRUE/FALSE Boolean values.
+    * Default: `false`
 
 
 For examples, please refer to the [json2csv API Documentation (Link)](https://github.com/mrodrig/json-2-csv/wiki/json2csv-Documentation)

lib/constants.json

@@ -35,7 +35,8 @@
     "unwindArrays": false,
     "useDateIso8601Format": false,
     "useLocaleFormat": false,
-    "parseValue": null
+    "parseValue": null,
+    "wrapBooleans": false
   },
 
   "values" : {

lib/json2csv.js

@@ -362,7 +362,8 @@ const Json2Csv = function(options) {
         //   then enclose it in quotation marks (wrap delimiter)
         if (fieldValue.includes(options.delimiter.field) ||
             fieldValue.includes(options.delimiter.wrap) ||
-            fieldValue.match(crlfSearchRegex)) {
+            fieldValue.match(crlfSearchRegex) ||
+            options.wrapBooleans && (fieldValue === 'true' || fieldValue === 'false')) {
             // wrap the field's value in a wrap delimiter (quotation marks by default)
             fieldValue = wrapDelimiter + fieldValue + wrapDelimiter;
         }

test/json2csv.js

@@ -618,6 +618,25 @@ function runTests(jsonTestData, csvTestData) {
                     parseValue: () => 'Parsed Value'
                 });
             });
+
+            it('should wrap boolean values in wrap delimiters, if specified', (done) => {
+                converter.json2csv(jsonTestData.emptyFieldValues, (err, csv) => {
+                    if (err) done(err);
+
+                    // Replace raw boolean values with quoted versions
+                    let expectedCsv = csvTestData.emptyFieldValues
+                        .replace(',"",', ',,')
+                        .replace(/\n"",/g, '\n,')
+                        .replace(/false/g, '"false"')
+                        .replace(/true/g, '"true"');
+
+                    csv.should.equal(expectedCsv);
+                    done();
+                }, {
+                    emptyFieldValue: '',
+                    wrapBooleans: true
+                });
+            });
         });
     });