Fix issue with fields.value function not receiving correct fields

lib/JSON2CSVBase.js

@@ -67,10 +67,11 @@ class JSON2CSVBase {
         }
 
         if (typeof fieldInfo.value === 'function') {
+          const label = fieldInfo.label || fieldInfo.value;
+          const field = { label, default: defaultValue };
           return {
-            label: fieldInfo.label || fieldInfo.value,
-            value: row => {
-              const field = { label: this.label, default: defaultValue };
+            label,
+            value(row) {
               const value = fieldInfo.value(row, field);
               return (value === null || value === undefined)
                 ? defaultValue

test/CLI.js

@@ -242,6 +242,17 @@ module.exports = (testRunner, jsonFixtures, csvFixtures) => {
     });
   });
 
+  testRunner.add('field.value function should receive a valid field object', (t) => {
+    const opts = ' --fields-config ' + getFixturePath('/fields/functionWithCheck.js');
+
+    child_process.exec(cli + '-i ' + getFixturePath('/json/functionStringifyByDefault.json') + opts, (err, stdout, stderr) => {
+      t.notOk(stderr);
+      const csv = stdout;
+      t.equal(csv, csvFixtures.functionStringifyByDefault);
+      t.end();
+    });
+  });
+
   testRunner.add('field.value function should stringify results by default', (t) => {
     const opts = ' --fields-config ' + getFixturePath('/fields/functionStringifyByDefault.js');
 

test/JSON2CSVParser.js

@@ -244,6 +244,25 @@ module.exports = (testRunner, jsonFixtures, csvFixtures) => {
     t.end();
   });
 
+  testRunner.add('field.value function should receive a valid field object', (t) => {
+    const opts = {
+      fields: [{
+        label: 'Value1',
+        default: 'default value',
+        value: (row, field) => {
+          t.deepEqual(field, { label: 'Value1', default: 'default value' });
+          return row.value1.toLocaleString();
+        }
+      }]
+    };
+
+    const parser = new Json2csvParser(opts);
+    const csv = parser.parse(jsonFixtures.functionStringifyByDefault);
+
+    t.equal(csv, csvFixtures.functionStringifyByDefault);
+    t.end();
+  });
+
   testRunner.add('field.value function should stringify results by default', (t) => {
     const opts = {
       fields: [{

test/JSON2CSVTransform.js

@@ -374,6 +374,31 @@ module.exports = (testRunner, jsonFixtures, csvFixtures, inMemoryJsonFixtures) =
       .on('error', err => t.notOk(true, err.message));
   });
 
+  testRunner.add('field.value function should receive a valid field object', (t) => {
+    const opts = {
+      fields: [{
+        label: 'Value1',
+        default: 'default value',
+        value: (row, field) => {
+          t.deepEqual(field, { label: 'Value1', default: 'default value' });
+          return row.value1.toLocaleString();
+        }
+      }]
+    };
+
+    const transform = new Json2csvTransform(opts);
+    const processor = jsonFixtures.functionStringifyByDefault().pipe(transform);
+
+    let csv = '';
+    processor
+      .on('data', chunk => (csv += chunk.toString()))
+      .on('end', () => {
+        t.equal(csv, csvFixtures.functionStringifyByDefault);
+        t.end();
+      })
+      .on('error', err => t.notOk(true, err.message));
+  });
+
   testRunner.add('field.value function should stringify results by default', (t) => {
     const opts = {
       fields: [{

test/fixtures/fields/functionWithCheck.js

@@ -0,0 +1,9 @@
+module.exports = [{
+  label: 'Value1',
+  value: (row, field) => {
+    if(field.label !== 'Value1' && field.default !== 'default value') {
+      throw new Error(`Expected ${JSON.stringify(field)} to equals ${JSON.stringify({ label: 'Value1', default: 'default value' })}.`);
+    }
+    return row.value1.toLocaleString();
+  }
+}];