[[FIX]] Correctly parse empty destructuring

Example: let {} = {}; function x([]) {} Fixes #2513
jshint · Jul 17, 2015 · 97c188b · 97c188b
1 parent d261071
commit 97c188b
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Showing 3 changed files with 34 additions and 16 deletions.
diff --git a/src/jshint.js b/src/jshint.js
@@ -3260,12 +3260,16 @@ var JSHINT = (function() {
     };
     if (checkPunctuators(state.tokens.next, ["["])) {
       advance("[");
-      var element_after_rest = false;
-      if (nextInnerDE() && checkPunctuators(state.tokens.next, [","])) {
-        warning("W130", state.tokens.next);
-        element_after_rest = true;
+      if (checkPunctuators(state.tokens.next, ["]"])) {
+        warning("W137", state.tokens.curr);
       }
+      var element_after_rest = false;
       while (!checkPunctuators(state.tokens.next, ["]"])) {
+        if (nextInnerDE() && !element_after_rest &&
+            checkPunctuators(state.tokens.next, [","])) {
+          warning("W130", state.tokens.next);
+          element_after_rest = true;
+        }
         if (checkPunctuators(state.tokens.next, ["="])) {
           if (checkPunctuators(state.tokens.prev, ["..."])) {
             advance("]");
@@ -3279,22 +3283,16 @@ var JSHINT = (function() {
         }
         if (!checkPunctuators(state.tokens.next, ["]"])) {
           advance(",");
-          if (checkPunctuators(state.tokens.next, ["]"])) {
-            // Trailing comma
-            break;
-          }
-          if (nextInnerDE() && checkPunctuators(state.tokens.next, [","]) &&
-              !element_after_rest) {
-            warning("W130", state.tokens.next);
-            element_after_rest = true;
-          }
         }
       }
       advance("]");
     } else if (checkPunctuators(state.tokens.next, ["{"])) {
       advance("{");
-      assignmentProperty();
+      if (checkPunctuators(state.tokens.next, ["}"])) {
+        warning("W137", state.tokens.curr);
+      }
       while (!checkPunctuators(state.tokens.next, ["}"])) {
+        assignmentProperty();
         if (checkPunctuators(state.tokens.next, ["="])) {
           advance("=");
           if (state.tokens.next.id === "undefined") {
@@ -3309,7 +3307,6 @@ var JSHINT = (function() {
             // ObjectBindingPattern: { BindingPropertyList , }
             break;
           }
-          assignmentProperty();
         }
       }
       advance("}");

diff --git a/src/messages.js b/src/messages.js
@@ -214,7 +214,8 @@ var warnings = {
   W133: "Invalid for-{a} loop left-hand-side: {b}.",
   W134: "The '{a}' option is only available when linting ECMAScript {b} code.",
   W135: "{a} may not be supported by non-browser environments.",
-  W136: "'{a}' must be in function scope."
+  W136: "'{a}' must be in function scope.",
+  W137: "Empty destructuring."
 };
 
 var info = {

diff --git a/tests/unit/parser.js b/tests/unit/parser.js
@@ -1811,6 +1811,26 @@ exports["non-identifier PropertyNames in object destructuring"] = function (test
   test.done();
 };
 
+exports["empty destructuring"] = function (test) {
+  var code = [
+    "var {} = {};",
+    "var [] = [];",
+    "function a({}, []) {}",
+    "var b = ({}) => ([]) => ({});"
+  ];
+
+  TestRun(test)
+    .addError(1, "Empty destructuring.")
+    .addError(2, "Empty destructuring.")
+    .addError(3, "Empty destructuring.")
+    .addError(3, "Empty destructuring.")
+    .addError(4, "Empty destructuring.")
+    .addError(4, "Empty destructuring.")
+    .test(code, { esnext: true });
+
+  test.done();
+};
+
 exports["array element assignment inside array"] = function (test) {
   var code = [
     "var a1 = {};",