diff --git a/eslint/babel-eslint-plugin/README.md b/eslint/babel-eslint-plugin/README.md
index 48611f3cd3..a712dee52c 100644
--- a/eslint/babel-eslint-plugin/README.md
+++ b/eslint/babel-eslint-plugin/README.md
@@ -33,7 +33,8 @@ original ones as well!).
     "babel/object-shorthand": 1,
     "babel/arrow-parens": 1,
     "babel/no-await-in-loop": 1,
-    "babel/flow-object-type": 1
+    "babel/flow-object-type": 1,
+    "babel/func-params-comma-dangle": 1
   }
 }
 ```
@@ -57,3 +58,4 @@ the current JavaScript standard or supported by `eslint`.
 - `babel/flow-object-type`: Require a particular separator between properties in Flow object types. (🛠 )
   - Use the option `semicolon` to require semicolons (e.g. `type Foo = { bar: number; baz: string }`).
   - Use the option `comma` to require commas (e.g. `type Foo = { bar: number, baz: string }`).
+- `babel/func-params-comma-dangle`: Require or forbid trailing commas for function paramater lists. Behaves like, and takes the same options as, `eslint`'s [`comma-dangle`](http://eslint.org/docs/rules/comma-dangle). (🛠 )
diff --git a/eslint/babel-eslint-plugin/index.js b/eslint/babel-eslint-plugin/index.js
index 7a3f7f4617..3656458f0b 100644
--- a/eslint/babel-eslint-plugin/index.js
+++ b/eslint/babel-eslint-plugin/index.js
@@ -10,6 +10,7 @@ module.exports = {
     'arrow-parens': require('./rules/arrow-parens'),
     'no-await-in-loop': require('./rules/no-await-in-loop'),
     'flow-object-type': require('./rules/flow-object-type'),
+    'func-params-comma-dangle': require('./rules/func-params-comma-dangle'),
   },
   rulesConfig: {
     'generator-star-spacing': 0,
@@ -20,5 +21,6 @@ module.exports = {
     'arrow-parens': 0,
     'no-await-in-loop': 0,
     'flow-object-type': 0,
+    'func-params-comma-dangle': 0,
   }
 };
diff --git a/eslint/babel-eslint-plugin/rules/func-params-comma-dangle.js b/eslint/babel-eslint-plugin/rules/func-params-comma-dangle.js
new file mode 100644
index 0000000000..d750323d39
--- /dev/null
+++ b/eslint/babel-eslint-plugin/rules/func-params-comma-dangle.js
@@ -0,0 +1,137 @@
+'use strict';
+
+// Based on https://github.com/eslint/eslint/blob/v2.11.1/lib/rules/comma-dangle.js
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+function last(arr) {
+  return arr.length !== 0 ? arr[arr.length - 1] : undefined;
+}
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = function(context) {
+    var mode = context.options[0];
+    var UNEXPECTED_MESSAGE = 'Unexpected trailing comma.';
+    var MISSING_MESSAGE = 'Missing trailing comma.';
+
+    function isMultiline(node) {
+      var lastItem = last(node.params || node.arguments);
+
+      if (!lastItem) {
+        return false;
+      }
+
+      var sourceCode = context.getSourceCode();
+      var penultimateToken = sourceCode.getLastToken(lastItem);
+      var lastToken = sourceCode.getTokenAfter(penultimateToken);
+
+      if (lastToken.value === ',') {
+        penultimateToken = lastToken;
+        lastToken = sourceCode.getTokenAfter(lastToken);
+      }
+
+      return lastToken.loc.end.line !== penultimateToken.loc.end.line;
+    }
+
+    function forbidTrailingComma(node) {
+      var lastItem = last(node.params || node.arguments);
+
+      if (!lastItem) {
+        return;
+      }
+
+      var sourceCode = context.getSourceCode();
+      var trailingToken = sourceCode.getTokenAfter(lastItem);
+
+      if (trailingToken.value === ',') {
+        context.report({
+          node: lastItem,
+          loc: trailingToken.loc.start,
+          message: UNEXPECTED_MESSAGE,
+          fix: function(fixer) {
+            return fixer.remove(trailingToken);
+          }
+        });
+      }
+    }
+
+    function forceTrailingComma(node) {
+      var lastItem = last(node.params || node.arguments);
+
+      if (!lastItem) {
+        return;
+      }
+
+      // `f(...a,)` is ok, but `function f(...a,) {}` is invalid syntax.
+      if (lastItem.type === 'RestElement') {
+        return;
+      }
+
+      var sourceCode = context.getSourceCode();
+      var penultimateToken = lastItem;
+      var trailingToken = sourceCode.getTokenAfter(lastItem);
+
+      // `f = a, => {}` is invalid syntax.
+      if (node.type === 'ArrowFunctionExpression' &&
+          node.params.length === 1 &&
+          sourceCode.getTokenBefore(lastItem).value !== '(') {
+        return;
+      }
+
+      if (trailingToken.value !== ',') {
+        context.report({
+          node: lastItem,
+          loc: lastItem.loc.end,
+          message: MISSING_MESSAGE,
+          fix: function(fixer) {
+            return fixer.insertTextAfter(penultimateToken, ',');
+          }
+        });
+      }
+    }
+
+    function forceTrailingCommaIfMultiline(node) {
+      if (isMultiline(node)) {
+        forceTrailingComma(node);
+      } else {
+        forbidTrailingComma(node);
+      }
+    }
+
+    function allowTrailingCommaIfMultiline(node) {
+      if (!isMultiline(node)) {
+        forbidTrailingComma(node);
+      }
+    }
+
+    var checkForTrailingComma;
+    if (mode === 'always') {
+      checkForTrailingComma = forceTrailingComma;
+    } else if (mode === 'always-multiline') {
+      checkForTrailingComma = forceTrailingCommaIfMultiline;
+    } else if (mode === 'only-multiline') {
+      checkForTrailingComma = allowTrailingCommaIfMultiline;
+    } else {
+      checkForTrailingComma = forbidTrailingComma;
+    }
+
+    return {
+      ArrowFunctionExpression: checkForTrailingComma,
+      FunctionDeclaration: checkForTrailingComma,
+      FunctionExpression: checkForTrailingComma,
+      CallExpression: checkForTrailingComma,
+      NewExpression: checkForTrailingComma,
+    };
+};
+
+module.exports.fixable = 'code';
+module.exports.schema =  [
+  {
+    enum: ['always', 'always-multiline', 'only-multiline', 'never']
+  }
+];
diff --git a/eslint/babel-eslint-plugin/tests/func-params-comma-dangle.js b/eslint/babel-eslint-plugin/tests/func-params-comma-dangle.js
new file mode 100644
index 0000000000..9fc5c2110f
--- /dev/null
+++ b/eslint/babel-eslint-plugin/tests/func-params-comma-dangle.js
@@ -0,0 +1,278 @@
+'use strict';
+
+var rule = require('../rules/func-params-comma-dangle');
+var RuleTester = require('eslint').RuleTester;
+
+var MISSING_I = [{message: 'Missing trailing comma.', type: 'Identifier'}];
+var MISSING_AP = [{message: 'Missing trailing comma.', type: 'AssignmentPattern'}];
+var MISSING_SE = [{message: 'Missing trailing comma.', type: 'SpreadElement'}];
+var UNEXPECTED_I = [{message: 'Unexpected trailing comma.', type: 'Identifier'}];
+var UNEXPECTED_AP = [{message: 'Unexpected trailing comma.', type: 'AssignmentPattern'}];
+var UNEXPECTED_SE = [{message: 'Unexpected trailing comma.', type: 'SpreadElement'}];
+
+var ruleTester = new RuleTester({parser: 'babel-eslint'});
+ruleTester.run('func-params-comma-dangle', rule, {
+  valid: [
+    {code: 'function f() {}'},
+    {code: 'function f(\n) {}'},
+    {code: 'function f(...a) {}'},
+    {code: 'function f(...a\n) {}'},
+
+    {code: 'f()'},
+    {code: 'f(\n)'},
+
+    {code: 'new F()'},
+    {code: 'new F(\n)'},
+
+    // FunctionDeclaration
+    {code: 'function f(a) {}', options: ['always-multiline']},
+    {code: 'function f(a) {}', options: ['never']},
+    {code: 'function f(a) {}', options: ['only-multiline']},
+    {code: 'function f(a,) {}', options: ['always']},
+    {code: 'function f(a,\n) {}', options: ['always']},
+    {code: 'function f(a,\n) {}', options: ['always-multiline']},
+    {code: 'function f(a,\n) {}', options: ['only-multiline']},
+    {code: 'function f(a\n) {}', options: ['never']},
+    {code: 'function f(a\n) {}', options: ['only-multiline']},
+
+    {code: 'function f(a=1) {}', options: ['always-multiline']},
+    {code: 'function f(a=1) {}', options: ['never']},
+    {code: 'function f(a=1) {}', options: ['only-multiline']},
+    {code: 'function f(a=1,) {}', options: ['always']},
+    {code: 'function f(a=1,\n) {}', options: ['always']},
+    {code: 'function f(a=1,\n) {}', options: ['always-multiline']},
+    {code: 'function f(a=1,\n) {}', options: ['only-multiline']},
+    {code: 'function f(a=1\n) {}', options: ['never']},
+    {code: 'function f(a=1\n) {}', options: ['only-multiline']},
+
+    {code: 'function f(a:T) {}', options: ['always-multiline']},
+    {code: 'function f(a:T) {}', options: ['never']},
+    {code: 'function f(a:T) {}', options: ['only-multiline']},
+    {code: 'function f(a:T,) {}', options: ['always']},
+    {code: 'function f(a:T,\n) {}', options: ['always']},
+    {code: 'function f(a:T,\n) {}', options: ['always-multiline']},
+    {code: 'function f(a:T,\n) {}', options: ['only-multiline']},
+    {code: 'function f(a:T\n) {}', options: ['never']},
+    {code: 'function f(a:T\n) {}', options: ['only-multiline']},
+
+    // FunctionExpression
+    {code: 'f = function(a) {}', options: ['always-multiline']},
+    {code: 'f = function(a) {}', options: ['never']},
+    {code: 'f = function(a) {}', options: ['only-multiline']},
+    {code: 'f = function(a,) {}', options: ['always']},
+    {code: 'f = function(a,\n) {}', options: ['always']},
+    {code: 'f = function(a,\n) {}', options: ['always-multiline']},
+    {code: 'f = function(a,\n) {}', options: ['only-multiline']},
+    {code: 'f = function(a\n) {}', options: ['never']},
+    {code: 'f = function(a\n) {}', options: ['only-multiline']},
+
+    {code: 'f = function(a=1) {}', options: ['always-multiline']},
+    {code: 'f = function(a=1) {}', options: ['never']},
+    {code: 'f = function(a=1) {}', options: ['only-multiline']},
+    {code: 'f = function(a=1,) {}', options: ['always']},
+    {code: 'f = function(a=1,\n) {}', options: ['always']},
+    {code: 'f = function(a=1,\n) {}', options: ['always-multiline']},
+    {code: 'f = function(a=1,\n) {}', options: ['only-multiline']},
+    {code: 'f = function(a=1\n) {}', options: ['never']},
+    {code: 'f = function(a=1\n) {}', options: ['only-multiline']},
+
+    {code: 'f = function(a:T) {}', options: ['always-multiline']},
+    {code: 'f = function(a:T) {}', options: ['never']},
+    {code: 'f = function(a:T) {}', options: ['only-multiline']},
+    {code: 'f = function(a:T,) {}', options: ['always']},
+    {code: 'f = function(a:T,\n) {}', options: ['always']},
+    {code: 'f = function(a:T,\n) {}', options: ['always-multiline']},
+    {code: 'f = function(a:T,\n) {}', options: ['only-multiline']},
+    {code: 'f = function(a:T\n) {}', options: ['never']},
+    {code: 'f = function(a:T\n) {}', options: ['only-multiline']},
+
+    // ArrowFunctionExpression
+    {code: 'f = (a) => {}', options: ['always-multiline']},
+    {code: 'f = (a) => {}', options: ['never']},
+    {code: 'f = (a) => {}', options: ['only-multiline']},
+    {code: 'f = (a,) => {}', options: ['always']},
+    {code: 'f = (a,\n) => {}', options: ['always']},
+    {code: 'f = (a,\n) => {}', options: ['always-multiline']},
+    {code: 'f = (a,\n) => {}', options: ['only-multiline']},
+    {code: 'f = (a\n) => {}', options: ['never']},
+    {code: 'f = (a\n) => {}', options: ['only-multiline']},
+
+    {code: 'f = a => {}', options: ['always-multiline']},
+    {code: 'f = a => {}', options: ['never']},
+    {code: 'f = a => {}', options: ['only-multiline']},
+    {code: 'f = a => {}', options: ['always']},
+
+    {code: 'f = (a=1) => {}', options: ['always-multiline']},
+    {code: 'f = (a=1) => {}', options: ['never']},
+    {code: 'f = (a=1) => {}', options: ['only-multiline']},
+    {code: 'f = (a=1,) => {}', options: ['always']},
+    {code: 'f = (a=1,\n) => {}', options: ['always']},
+    {code: 'f = (a=1,\n) => {}', options: ['always-multiline']},
+    {code: 'f = (a=1,\n) => {}', options: ['only-multiline']},
+    {code: 'f = (a=1\n) => {}', options: ['never']},
+    {code: 'f = (a=1\n) => {}', options: ['only-multiline']},
+
+    {code: 'f = (a:T) => {}', options: ['always-multiline']},
+    {code: 'f = (a:T) => {}', options: ['never']},
+    {code: 'f = (a:T) => {}', options: ['only-multiline']},
+    // Arrow functions with flow types aren't getting the correct loc.
+    // {code: 'f = (a:T,) => {}', options: ['always']},
+    // {code: 'f = (a:T,\n) => {}', options: ['always']},
+    {code: 'f = (a:T,\n) => {}', options: ['always-multiline']},
+    {code: 'f = (a:T,\n) => {}', options: ['only-multiline']},
+    {code: 'f = (a:T\n) => {}', options: ['never']},
+    {code: 'f = (a:T\n) => {}', options: ['only-multiline']},
+
+    // CallExpression
+    {code: 'f(a)', options: ['always-multiline']},
+    {code: 'f(a)', options: ['never']},
+    {code: 'f(a)', options: ['only-multiline']},
+    {code: 'f(a,)', options: ['always']},
+    {code: 'f(a,\n)', options: ['always']},
+    {code: 'f(a,\n)', options: ['always-multiline']},
+    {code: 'f(a,\n)', options: ['only-multiline']},
+    {code: 'f(a\n)', options: ['never']},
+    {code: 'f(a\n)', options: ['only-multiline']},
+    {code: 'f(...a)', options: ['always-multiline']},
+    {code: 'f(...a)', options: ['never']},
+    {code: 'f(...a)', options: ['only-multiline']},
+    {code: 'f(...a,)', options: ['always']},
+    {code: 'f(...a,\n)', options: ['always']},
+    {code: 'f(...a,\n)', options: ['always-multiline']},
+    {code: 'f(...a,\n)', options: ['only-multiline']},
+    {code: 'f(...a\n)', options: ['never']},
+    {code: 'f(...a\n)', options: ['only-multiline']},
+
+    // NewExpression
+    {code: 'new F(a)', options: ['always-multiline']},
+    {code: 'new F(a)', options: ['never']},
+    {code: 'new F(a)', options: ['only-multiline']},
+    {code: 'new F(a,)', options: ['always']},
+    {code: 'new F(a,\n)', options: ['always']},
+    {code: 'new F(a,\n)', options: ['always-multiline']},
+    {code: 'new F(a,\n)', options: ['only-multiline']},
+    {code: 'new F(a\n)', options: ['never']},
+    {code: 'new F(a\n)', options: ['only-multiline']},
+    {code: 'new F(...a)', options: ['always-multiline']},
+    {code: 'new F(...a)', options: ['never']},
+    {code: 'new F(...a)', options: ['only-multiline']},
+    {code: 'new F(...a,)', options: ['always']},
+    {code: 'new F(...a,\n)', options: ['always']},
+    {code: 'new F(...a,\n)', options: ['always-multiline']},
+    {code: 'new F(...a,\n)', options: ['only-multiline']},
+    {code: 'new F(...a\n)', options: ['never']},
+    {code: 'new F(...a\n)', options: ['only-multiline']},
+  ],
+  invalid: [
+    // FunctionDeclaration
+    {code: 'function f(a) {}', output: 'function f(a,) {}', options: ['always'], errors: MISSING_I},
+    {code: 'function f(a,) {}', output: 'function f(a) {}', options: ['always-multiline'], errors: UNEXPECTED_I},
+    {code: 'function f(a,) {}', output: 'function f(a) {}', options: ['only-multiline'], errors: UNEXPECTED_I},
+    {code: 'function f(a,) {}', output: 'function f(a) {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'function f(a,\n) {}', output: 'function f(a\n) {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'function f(a\n) {}', output: 'function f(a,\n) {}', options: ['always'], errors: MISSING_I},
+    {code: 'function f(a\n) {}', output: 'function f(a,\n) {}', options: ['always-multiline'], errors: MISSING_I},
+
+    {code: 'function f(a=1) {}', output: 'function f(a=1,) {}', options: ['always'], errors: MISSING_AP},
+    {code: 'function f(a=1,) {}', output: 'function f(a=1) {}', options: ['always-multiline'], errors: UNEXPECTED_AP},
+    {code: 'function f(a=1,) {}', output: 'function f(a=1) {}', options: ['always-multiline'], errors: UNEXPECTED_AP},
+    {code: 'function f(a=1,) {}', output: 'function f(a=1) {}', options: ['only-multiline'], errors: UNEXPECTED_AP},
+    {code: 'function f(a=1,) {}', output: 'function f(a=1) {}', options: ['never'], errors: UNEXPECTED_AP},
+    {code: 'function f(a=1,\n) {}', output: 'function f(a=1\n) {}', options: ['never'], errors: UNEXPECTED_AP},
+    {code: 'function f(a=1\n) {}', output: 'function f(a=1,\n) {}', options: ['always'], errors: MISSING_AP},
+    {code: 'function f(a=1\n) {}', output: 'function f(a=1,\n) {}', options: ['always-multiline'], errors: MISSING_AP},
+
+    {code: 'function f(a:T) {}', output: 'function f(a:T,) {}', options: ['always'], errors: MISSING_I},
+    {code: 'function f(a:T,) {}', output: 'function f(a:T) {}', options: ['always-multiline'], errors: UNEXPECTED_I},
+    {code: 'function f(a:T,) {}', output: 'function f(a:T) {}', options: ['only-multiline'], errors: UNEXPECTED_I},
+    {code: 'function f(a:T,) {}', output: 'function f(a:T) {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'function f(a:T,\n) {}', output: 'function f(a:T\n) {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'function f(a:T\n) {}', output: 'function f(a:T,\n) {}', options: ['always'], errors: MISSING_I},
+    {code: 'function f(a:T\n) {}', output: 'function f(a:T,\n) {}', options: ['always-multiline'], errors: MISSING_I},
+
+    // FunctionExpression
+    {code: 'f = function f(a) {}', output: 'f = function f(a,) {}', options: ['always'], errors: MISSING_I},
+    {code: 'f = function f(a,) {}', output: 'f = function f(a) {}', options: ['always-multiline'], errors: UNEXPECTED_I},
+    {code: 'f = function f(a,) {}', output: 'f = function f(a) {}', options: ['only-multiline'], errors: UNEXPECTED_I},
+    {code: 'f = function f(a,) {}', output: 'f = function f(a) {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'f = function f(a,\n) {}', output: 'f = function f(a\n) {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'f = function f(a\n) {}', output: 'f = function f(a,\n) {}', options: ['always'], errors: MISSING_I},
+    {code: 'f = function f(a\n) {}', output: 'f = function f(a,\n) {}', options: ['always-multiline'], errors: MISSING_I},
+
+    {code: 'f = function f(a=1) {}', output: 'f = function f(a=1,) {}', options: ['always'], errors: MISSING_AP},
+    {code: 'f = function f(a=1,) {}', output: 'f = function f(a=1) {}', options: ['always-multiline'], errors: UNEXPECTED_AP},
+    {code: 'f = function f(a=1,) {}', output: 'f = function f(a=1) {}', options: ['only-multiline'], errors: UNEXPECTED_AP},
+    {code: 'f = function f(a=1,) {}', output: 'f = function f(a=1) {}', options: ['never'], errors: UNEXPECTED_AP},
+    {code: 'f = function f(a=1,\n) {}', output: 'f = function f(a=1\n) {}', options: ['never'], errors: UNEXPECTED_AP},
+    {code: 'f = function f(a=1\n) {}', output: 'f = function f(a=1,\n) {}', options: ['always'], errors: MISSING_AP},
+    {code: 'f = function f(a=1\n) {}', output: 'f = function f(a=1,\n) {}', options: ['always-multiline'], errors: MISSING_AP},
+
+    {code: 'f = function f(a:T) {}', output: 'f = function f(a:T,) {}', options: ['always'], errors: MISSING_I},
+    {code: 'f = function f(a:T,) {}', output: 'f = function f(a:T) {}', options: ['always-multiline'], errors: UNEXPECTED_I},
+    {code: 'f = function f(a:T,) {}', output: 'f = function f(a:T) {}', options: ['only-multiline'], errors: UNEXPECTED_I},
+    {code: 'f = function f(a:T,) {}', output: 'f = function f(a:T) {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'f = function f(a:T,\n) {}', output: 'f = function f(a:T\n) {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'f = function f(a:T\n) {}', output: 'f = function f(a:T,\n) {}', options: ['always'], errors: MISSING_I},
+    {code: 'f = function f(a:T\n) {}', output: 'f = function f(a:T,\n) {}', options: ['always-multiline'], errors: MISSING_I},
+
+    // ArrowFunctionExpression
+    {code: 'f = (a) => {}', output: 'f = (a,) => {}', options: ['always'], errors: MISSING_I},
+    {code: 'f = (a,) => {}', output: 'f = (a) => {}', options: ['always-multiline'], errors: UNEXPECTED_I},
+    {code: 'f = (a,) => {}', output: 'f = (a) => {}', options: ['only-multiline'], errors: UNEXPECTED_I},
+    {code: 'f = (a,) => {}', output: 'f = (a) => {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'f = (a,\n) => {}', output: 'f = (a\n) => {}', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'f = (a\n) => {}', output: 'f = (a,\n) => {}', options: ['always'], errors: MISSING_I},
+    {code: 'f = (a\n) => {}', output: 'f = (a,\n) => {}', options: ['always-multiline'], errors: MISSING_I},
+
+    {code: 'f = (a=1) => {}', output: 'f = (a=1,) => {}', options: ['always'], errors: MISSING_AP},
+    {code: 'f = (a=1,) => {}', output: 'f = (a=1) => {}', options: ['always-multiline'], errors: UNEXPECTED_AP},
+    {code: 'f = (a=1,) => {}', output: 'f = (a=1) => {}', options: ['only-multiline'], errors: UNEXPECTED_AP},
+    {code: 'f = (a=1,) => {}', output: 'f = (a=1) => {}', options: ['never'], errors: UNEXPECTED_AP},
+    {code: 'f = (a=1,\n) => {}', output: 'f = (a=1\n) => {}', options: ['never'], errors: UNEXPECTED_AP},
+    {code: 'f = (a=1\n) => {}', output: 'f = (a=1,\n) => {}', options: ['always'], errors: MISSING_AP},
+    {code: 'f = (a=1\n) => {}', output: 'f = (a=1,\n) => {}', options: ['always-multiline'], errors: MISSING_AP},
+
+    // Arrow functions with flow types aren't getting the correct loc.
+    // {code: 'f = (a:T) => {}', output: 'f = (a:T,) => {}', options: ['always'], errors: MISSING_I},
+    // {code: 'f = (a:T,) => {}', output: 'f = (a:T) => {}', options: ['always-multiline'], errors: UNEXPECTED_I},
+    // {code: 'f = (a:T,) => {}', output: 'f = (a:T) => {}', options: ['only-multiline'], errors: UNEXPECTED_I},
+    // {code: 'f = (a:T,) => {}', output: 'f = (a:T) => {}', options: ['never'], errors: UNEXPECTED_I},
+    // {code: 'f = (a:T,\n) => {}', output: 'f = (a:T\n) => {}', options: ['never'], errors: UNEXPECTED_I},
+    // {code: 'f = (a:T\n) => {}', output: 'f = (a:T,\n) => {}', options: ['always'], errors: MISSING_I},
+    // {code: 'f = (a:T\n) => {}', output: 'f = (a:T,\n) => {}', options: ['always-multiline'], errors: MISSING_I},
+
+    // CallExpression
+    {code: 'f(a)', output: 'f(a,)', options: ['always'], errors: MISSING_I},
+    {code: 'f(a,)', output: 'f(a)', options: ['always-multiline'], errors: UNEXPECTED_I},
+    {code: 'f(a,)', output: 'f(a)', options: ['only-multiline'], errors: UNEXPECTED_I},
+    {code: 'f(a,)', output: 'f(a)', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'f(a,\n)', output: 'f(a\n)', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'f(a\n)', output: 'f(a,\n)', options: ['always'], errors: MISSING_I},
+    {code: 'f(a\n)', output: 'f(a,\n)', options: ['always-multiline'], errors: MISSING_I},
+
+    {code: 'f(...a)', output: 'f(...a,)', options: ['always'], errors: MISSING_SE},
+    {code: 'f(...a,)', output: 'f(...a)', options: ['always-multiline'], errors: UNEXPECTED_SE},
+    {code: 'f(...a,)', output: 'f(...a)', options: ['only-multiline'], errors: UNEXPECTED_SE},
+    {code: 'f(...a,)', output: 'f(...a)', options: ['never'], errors: UNEXPECTED_SE},
+    {code: 'f(...a,\n)', output: 'f(...a\n)', options: ['never'], errors: UNEXPECTED_SE},
+    {code: 'f(...a\n)', output: 'f(...a,\n)', options: ['always'], errors: MISSING_SE},
+    {code: 'f(...a\n)', output: 'f(...a,\n)', options: ['always-multiline'], errors: MISSING_SE},
+
+    // NewExpression
+    {code: 'new F(a)', output: 'new F(a,)', options: ['always'], errors: MISSING_I},
+    {code: 'new F(a,)', output: 'new F(a)', options: ['always-multiline'], errors: UNEXPECTED_I},
+    {code: 'new F(a,)', output: 'new F(a)', options: ['only-multiline'], errors: UNEXPECTED_I},
+    {code: 'new F(a,)', output: 'new F(a)', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'new F(a,\n)', output: 'new F(a\n)', options: ['never'], errors: UNEXPECTED_I},
+    {code: 'new F(a\n)', output: 'new F(a,\n)', options: ['always'], errors: MISSING_I},
+    {code: 'new F(a\n)', output: 'new F(a,\n)', options: ['always-multiline'], errors: MISSING_I},
+
+    {code: 'new F(...a)', output: 'new F(...a,)', options: ['always'], errors: MISSING_SE},
+    {code: 'new F(...a,)', output: 'new F(...a)', options: ['always-multiline'], errors: UNEXPECTED_SE},
+    {code: 'new F(...a,)', output: 'new F(...a)', options: ['only-multiline'], errors: UNEXPECTED_SE},
+    {code: 'new F(...a,)', output: 'new F(...a)', options: ['never'], errors: UNEXPECTED_SE},
+    {code: 'new F(...a,\n)', output: 'new F(...a\n)', options: ['never'], errors: UNEXPECTED_SE},
+    {code: 'new F(...a\n)', output: 'new F(...a,\n)', options: ['always'], errors: MISSING_SE},
+    {code: 'new F(...a\n)', output: 'new F(...a,\n)', options: ['always-multiline'], errors: MISSING_SE},
+  ],
+});