The following valid ES6 in WebStorm:
let {a,b} = {a:0,b:0};
{a,b} = {a:2,b:4};
shows an error at the second equals sign: "expression expected". Obviously JavaScript settings are set to ES6.
By the way adding parentheses removes the error:
let {a,b} = {a:0,b:0};
({a,b} = {a:2,b:4});
Is this a bug or part of the ES6? The node compiler seems to have no problem with the first version (without the parentheses), so it doesn't seem to be part of the standard.
This is not a bug, this is how ExpressionStatement are:
NOTE An ExpressionStatement cannot start with a U+007B (LEFT CURLY BRACKET) because that might make it ambiguous with a Block. An ExpressionStatement cannot start with the function or class keywords because that would make it ambiguous with a FunctionDeclaration, a GeneratorDeclaration, or a ClassDeclaration. An ExpressionStatement cannot start with async function because that would make it ambiguous with an AsyncFunctionDeclaration. An ExpressionStatement cannot start with the two token sequence let [ because that would make it ambiguous with a let LexicalDeclaration whose first LexicalBinding was an ArrayBindingPattern.
Put parens around your assignment. For example, the following is correct
let foo
({foo = 3} = {foo: 2})
let {a,b}= {a:0,b:0}or the second version.let, since theaandbvariables will be global. Not evenvar. Just global variables.function x() { ({a,b} = {a:2,b:4}); }. After calling this function you will be able to access these variables in global scope. If it would beconst,letor evenvar, you wouldn't have access to it outside function.