Add logic to wrap booleans when specified. (#189)

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

Author: mrodrig

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
+                });
+            });
         });
     });