fix: bug that modifies opts after parsing an object/stream (#318)

zemirco · Aug 6, 2018 · f0a4830 · f0a4830
1 parent ee3d181
commit f0a4830
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Showing 3 changed files with 39 additions and 1 deletion.
diff --git a/lib/JSON2CSVBase.js b/lib/JSON2CSVBase.js
@@ -17,7 +17,7 @@ class JSON2CSVBase {
    * delimiter, default value, quote mark, header, etc.
    */
   preprocessOpts(opts) {
-    const processedOpts = opts || {};
+    const processedOpts = Object.assign({}, opts);
     processedOpts.unwind = !Array.isArray(processedOpts.unwind)
       ? (processedOpts.unwind ? [processedOpts.unwind] : [])
       : processedOpts.unwind

diff --git a/test/JSON2CSVParser.js b/test/JSON2CSVParser.js
@@ -4,6 +4,16 @@ const json2csv = require('../lib/json2csv');
 const Json2csvParser = json2csv.Parser;
 
 module.exports = (testRunner, jsonFixtures, csvFixtures) => {
+  testRunner.add('should not modify the opts passed using parse method', (t) => {
+    const opts = {};
+    const csv = json2csv.parse(jsonFixtures.default);
+
+    t.ok(typeof csv === 'string');
+    t.equal(csv, csvFixtures.default);
+    t.deepEqual(opts, {});
+    t.end();
+  });
+
   testRunner.add('should parse json to csv and infer the fields automatically using parse method', (t) => {
     const csv = json2csv.parse(jsonFixtures.default);
 
@@ -12,6 +22,17 @@ module.exports = (testRunner, jsonFixtures, csvFixtures) => {
     t.end();
   });
 
+  testRunner.add('should not modify the opts passed', (t) => {
+    const opts = {};
+    const parser = new Json2csvParser(opts);
+    const csv = parser.parse(jsonFixtures.default);
+
+    t.ok(typeof csv === 'string');
+    t.equal(csv, csvFixtures.default);
+    t.deepEqual(opts, {});
+    t.end();
+  });
+
   testRunner.add('should error if input data is not an object', (t) => {
     const input = 'not an object';
     try {

diff --git a/test/JSON2CSVTransform.js b/test/JSON2CSVTransform.js
@@ -42,6 +42,23 @@ module.exports = (testRunner, jsonFixtures, csvFixtures) => {
     });
   });
 
+  testRunner.add('should not modify the opts passed', (t) => {
+    const opts = {};
+    const transform = new Json2csvTransform(opts);
+    const processor = jsonFixtures.default().pipe(transform);
+
+    let csv = '';
+    processor
+      .on('data', chunk => (csv += chunk.toString()))
+      .on('end', () => {
+        t.ok(typeof csv === 'string');
+        t.equal(csv, csvFixtures.defaultStream);
+        t.deepEqual(opts, {});
+        t.end();
+      })
+      .on('error', err => t.notOk(true, err.message));
+  });
+
   testRunner.add('should error if input data is not an object', (t) => {
     const input = new Readable();
     input._read = () => {};