[[FIX]] Fix false positives in 'nocomma' option

- Fix false positives in nocomma in literals and for loops
- Fix false positives in nocomma in arrow function expression
- Add tests for false positives in destructuring with nocomma option

src/jshint.js

@@ -981,10 +981,6 @@ var JSHINT = (function() {
   function comma(opts) {
     opts = opts || {};
 
-    if (state.option.nocomma) {
-      warning("W127");
-    }
-
     if (!opts.peek) {
       nobreakcomma(state.tokens.curr, state.tokens.next);
       advance(",");
@@ -2063,6 +2059,11 @@ var JSHINT = (function() {
   infix(",", function(left, that) {
     var expr;
     that.exprs = [left];
+
+    if (state.option.nocomma) {
+      warning("W127");
+    }
+
     if (!comma({ peek: true })) {
       return that;
     }
@@ -2476,6 +2477,11 @@ var JSHINT = (function() {
         if (state.tokens.next.id !== ",") {
           break;
         }
+
+        if (pn1.value !== "=>" && state.option.nocomma) {
+          warning("W127");
+        }
+
         comma();
       }
     }

tests/unit/options.js

@@ -1680,17 +1680,35 @@ exports.nonbsp = function (test) {
 /** Option `nocomma` disallows the use of comma operator. */
 exports.nocomma = function (test) {
   // By default allow comma operator
-  TestRun(test)
+  TestRun(test, "nocomma off by default")
     .test("return 2, 5;", {});
 
-  TestRun(test)
+  TestRun(test, "nocomma main case")
     .addError(1, "Unexpected use of a comma operator.")
     .test("return 2, 5;", { nocomma: true });
 
-  TestRun(test)
+  TestRun(test, "nocomma in an expression")
     .addError(1, "Unexpected use of a comma operator.")
     .test("(2, 5);", { expr: true, nocomma: true });
 
+  TestRun(test, "avoid nocomma false positives in value literals")
+    .test("return { a: 2, b: [1, 2] };", { nocomma: true });
+
+  TestRun(test, "avoid nocomma false positives in for statements")
+    .test("for(;;) { return; }", { nocomma: true });
+
+  TestRun(test, "avoid nocomma false positives in function expressions")
+    .test("return function(a, b) {};", { nocomma: true });
+
+  TestRun(test, "avoid nocomma false positives in arrow function expressions")
+    .test("return (a, b) => a;", { esnext: true, nocomma: true });
+
+  TestRun(test, "avoid nocomma false positives in destructuring arrays")
+    .test("var [a, b] = [1, 2];", { esnext: true, nocomma: true });
+
+  TestRun(test, "avoid nocomma false positives in destructuring objects")
+    .test("var {a, b} = {a:1, b:2};", { esnext: true, nocomma: true });
+
   test.done();
 };