Ignoring the trailing comma rule for function parameter. Ignoring a not disallowing it because once node will support it, we’re going to want to have it.

Author: Magellol

.gitignore

@@ -1,3 +1,2 @@
 .idea/
-
 npm-debug.log

packages/eslint-config-transit/index.js

@@ -12,5 +12,12 @@ module.exports = {
     'max-len': ['error', 105, 2],
     'no-param-reassign': 'off',
     'no-use-before-define': 'off',
+    'comma-dangle': ['error', {
+      arrays: 'always-multiline',
+      objects: 'always-multiline',
+      imports: 'always-multiline',
+      exports: 'always-multiline',
+      functions: 'ignore',
+    }],
   },
 };

packages/eslint-config-transit/test/eslint-config-transit-test.js

@@ -33,3 +33,14 @@ if (reassignParameter) {
 else {
   functionDefinedBeforeUse();
 }
+
+// Trailing comma in function parameters should be ignored
+// It's a ES2017 features and it's not available in any Node JS version.
+function testMyTrailingComma(
+  a,
+  b
+) {
+  return a + b;
+}
+
+testMyTrailingComma();