Add arrayIndexesAsKeys option for #207

README.md

@@ -50,6 +50,9 @@ Returns the CSV `string` or rejects with an `Error` if there was an issue.
 
 * `array` - An array of JSON documents to be converted to CSV.
 * `options` - (Optional) A JSON document specifying any of the following key value pairs:
+  * `arrayIndexesAsKeys` - Boolean - Should array indexes be included in the generated keys?
+    * Default: `false`
+    * Note: This provides a more accurate representation of the JSON in the returned CSV, but may be less human readable. See [#207](https://github.com/mrodrig/json-2-csv/issues/207) for more details.
   * `checkSchemaDifferences` - Boolean - Should all documents have the same schema?
     * Default: `false`
     * Note: An error will be thrown if some documents have differing schemas when this is set to `true`.

package.json

@@ -39,8 +39,8 @@
         "cli"
     ],
     "dependencies": {
-        "deeks": "3.0.2",
-        "doc-path": "4.0.2"
+        "deeks": "3.1.0",
+        "doc-path": "4.1.0"
     },
     "devDependencies": {
         "@types/mocha": "10.0.1",

src/constants.ts

@@ -18,6 +18,7 @@ export const errors = {
 };
 
 export const defaultJson2CsvOptions: DefaultJson2CsvOptions = {
+    arrayIndexesAsKeys: false,
     checkSchemaDifferences: false,
     delimiter : {
         field : ',',

src/json2csv.ts

@@ -12,6 +12,7 @@ export const Json2Csv = function(options: FullJson2CsvOptions) {
         customValueParser = options.parseValue && typeof options.parseValue === 'function' ? options.parseValue : null,
         expandingWithoutUnwinding = options.expandArrayObjects && !options.unwindArrays,
         deeksOptions = {
+            arrayIndexesAsKeys: options.arrayIndexesAsKeys,
             expandNestedObjects: options.expandNestedObjects,
             expandArrayObjects: expandingWithoutUnwinding,
             ignoreEmptyArraysWhenExpanding: expandingWithoutUnwinding,

src/types.ts

@@ -87,6 +87,11 @@ export interface Csv2JsonOptions extends Omit<SharedConverterOptions, 'keys'> {
 }
 
 export interface Json2CsvOptions extends SharedConverterOptions {
+  /** Should array indexes be included in the generated keys?
+   * @default false
+   */
+  arrayIndexesAsKeys?: boolean;
+
   /**
    * Should all documents have the same schema?
    * @default false

test/config/testCsvFilesList.ts

@@ -52,6 +52,7 @@ const csvFileConfig = [
     {key: 'newlineWithWrapDelimiters', file: '../data/csv/newlineWithWrapDelimiters.csv'},
     {key: 'excludeKeyPattern', file: '../data/csv/excludeKeyPattern.csv'},
     {key: 'wildcardMatch', file: '../data/csv/wildcardMatch.csv'},
+    {key: 'arrayIndexesAsKeys', file: '../data/csv/arrayIndexesAsKeys.csv'},
 ];
 
 function readCsvFile(filePath: string) {

test/config/testJsonFilesList.ts

@@ -45,4 +45,5 @@ export default {
     newlineWithWrapDelimiters: require('../data/json/newlineWithWrapDelimiters'),
     excludeKeyPattern: require('../data/json/excludeKeyPattern'),
     wildcardMatch: require('../data/json/wildcardMatch.json'),
+    arrayIndexesAsKeys: require('../data/json/arrayIndexesAsKeys.json'),
 };

test/data/csv/arrayIndexesAsKeys.csv

@@ -0,0 +1,3 @@
+test.list.0.a,test.list.0.optionA,test.list.1.a,test.list.1.optionB
+1,ac,2,radio
+3,cd,4,heat

test/data/json/arrayIndexesAsKeys.json

@@ -0,0 +1,30 @@
+[
+    {
+        "test": {
+            "list": [
+                {
+                    "a": 1,
+                    "optionA": "ac"
+                },
+                {
+                    "a": 2,
+                    "optionB": "radio"
+                }
+            ]
+        }
+    },
+    {
+        "test": {
+            "list": [
+                {
+                    "a": 3,
+                    "optionA": "cd"
+                },
+                {
+                    "a": 4,
+                    "optionB": "heat"
+                }
+            ]
+        }
+    }
+]

test/json2csv.ts

@@ -578,6 +578,14 @@ export function runTests() {
                 assert.equal(csv, updatedCsv);
             });
 
+            // Test case for #207
+            it('should include the array indexes in CSV key headers if specified via the option', () => {
+                const csv = json2csv(jsonTestData.arrayIndexesAsKeys, {
+                    arrayIndexesAsKeys: true,
+                });
+                assert.equal(csv, csvTestData.arrayIndexesAsKeys);
+            });
+
             it('should use a custom value parser function when provided', () => {
                 const updatedCsv = csvTestData.trimmedFields.split('\n');
                 const textRow = 'Parsed Value,Parsed Value,Parsed Value,Parsed Value,Parsed Value';