fix: Remove fieldNames (#232)

BREAKING CHANGE: Remove fieldNames

* Increase coverage back to 100%

README.md

@@ -58,8 +58,6 @@ try {
 - `options` - **Required**; Options hash.
   - `data` - **Required**; Array of JSON objects.
   - `fields` - Array of Objects/Strings. Defaults to toplevel JSON attributes. See example below.
-  - `fieldNames` Array of Strings, names for the fields at the same indexes.
-    Must be the same length as `fields` array. (Optional. Maintained for backwards compatibility. Use `fields` config object for more features)
   - `delimiter` - String, delimiter of columns. Defaults to `,` if not specified.
   - `defaultValue` - String, default value to use when missing data. Defaults to `<empty>` if not specified. (Overridden by `fields[].default`)
   - `quote` - String, quote around cell values and column names. Defaults to `"` if not specified.
@@ -193,9 +191,14 @@ You can choose custom column names for the exported file.
 
 ```javascript
 var json2csv = require('json2csv');
-var fields = ['car', 'price'];
-var fieldNames = ['Car Name', 'Price USD'];
-var csv = json2csv({ data: myCars, fields: fields, fieldNames: fieldNames });
+var fields = [{
+  label: 'Car Name',
+  value: 'car'
+},{
+  label: 'Price USD',
+  value: 'price'
+}];
+var csv = json2csv({ data: myCars, fields: fields });
 
 console.log(csv);
 ```
@@ -207,11 +210,9 @@ You can choose custom quotation marks.
 ```javascript
 var json2csv = require('json2csv');
 var fields = ['car', 'price'];
-var fieldNames = ['Car Name', 'Price USD'];
 var opts = {
   data: myCars,
   fields: fields,
-  fieldNames: fieldNames,
   quote: ''
 };
 var csv = json2csv(opts);

index.d.ts

@@ -19,7 +19,6 @@ declare namespace json2csv {
   interface Options<T> {
     data: T[];
     fields?: (string | Field | CallbackField<T>)[];
-    fieldNames?: string[];
     delimiter?: string;
     defaultValue?: string;
     quote?: string;

lib/json2csv.js

@@ -14,8 +14,6 @@ var flatten = require('flat');
  * @typedef {Object}
  * @property {Array} data - array of JSON objects
  * @property {Array} [fields] - see documentation for details
- * @property {String[]} [fieldNames] - names for fields at the same indexes. Must be same length as fields array
- *                                   (Optional. Maintained for backwards compatibility. Use fields config object for more features)
  * @property {String} [delimiter=","] - delimiter of columns
  * @property {String} [defaultValue="<empty>"] - default value to use when missing data
  * @property {String} [quote='"'] - quote around cell values and column names
@@ -81,18 +79,11 @@ function checkParams(params) {
     params.fields = lodashUniq(dataFields);
   }
 
-
-  // check fieldNames
-  if (params.fieldNames && params.fieldNames.length !== params.fields.length) {
-    throw new Error('fieldNames and fields should be of the same length, if fieldNames is provided.');
-  }
-
   // Get fieldNames from fields
-  params.fieldNames = params.fields.map(function (field, i) {
-    if (params.fieldNames && typeof field === 'string') {
-      return params.fieldNames[i];
-    }
-    return (typeof field === 'string') ? field : (field.label || field.value);
+  params.fieldNames = params.fields.map(function (field) {
+    return (typeof field === 'string')
+      ? field
+      : (field.label || field.value);
   });
 
   // check delimiter

test/index.js

@@ -52,22 +52,6 @@ loadFixtures().then(function (csvFixtures) {
     t.end();
   });
 
-  test('should error if fieldNames don\'t line up to fields', function (t) {
-    var csv;
-    try {
-      csv = json2csv({
-        data: jsonDefault,
-        field: ['carModel'],
-        fieldNames: ['test', 'blah']
-      });
-      t.notOk(true);
-    } catch (error) {
-      t.equal(error.message, 'fieldNames and fields should be of the same length, if fieldNames is provided.');
-      t.notOk(csv);
-      t.end();
-    }
-  });
-
   test('should parse json to csv', function (t) {
     var csv = json2csv({
       data: jsonDefault,
@@ -238,22 +222,41 @@ loadFixtures().then(function (csvFixtures) {
     t.end();
   });
 
-  test('should name columns as specified in \'fieldNames\' property', function (t) {
+  test('should name columns as specified in \'fields\' property', function (t) {
     var csv = json2csv({
       data: jsonDefault,
-      fields: ['carModel', 'price'],
-      fieldNames: ['Car Model', 'Price USD']
+      fields: [{
+        label: 'Car Model',
+        value: 'carModel'
+      },{
+        label: 'Price USD',
+        value: 'price'
+      }]
     });
-
+    
     t.equal(csv, csvFixtures.fieldNames);
     t.end();
   });
 
   test('should output nested properties', function (t) {
     var csv = json2csv({
       data: jsonNested,
-      fields: ['car.make', 'car.model', 'price', 'color', 'car.ye.ar'],
-      fieldNames: ['Make', 'Model', 'Price', 'Color', 'Year']
+      fields: [{
+        label: 'Make',
+        value: 'car.make'
+      },{
+        label: 'Model',
+        value: 'car.model'
+      },{
+        label: 'Price',
+        value: 'price'
+      },{
+        label: 'Color',
+        value: 'color'
+      },{
+        label: 'Year',
+        value: 'car.ye.ar'
+      }]
     });
 
     t.equal(csv, csvFixtures.nested);
@@ -282,13 +285,28 @@ loadFixtures().then(function (csvFixtures) {
     t.end();
   });
 
-  test('should error if params is not an object', function (t) {
+  test('should error synchronously if fieldNames don\'t line up to fields', function (t) {
     var csv;
+
+    try {
+      csv = json2csv({
+        data: 'not an object',
+        field: ['carModel']
+      });
+      t.notOk(true);
+    } catch (error) {
+      t.equal(error.message, 'params should include "fields" and/or non-empty "data" array of objects');
+      t.notOk(csv);
+      t.end();
+    }
+  });
 
+  test('should error asynchronously if params is not an object', function (t) {
+    var csv;
+
     try {
       csv = json2csv({
         data: 'not an object',
-        field: ['carModel'],
         fieldNames: ['test', 'blah']
       });
     } catch(error) {