lib/rules/no-var.js
function isLoopAssignee(node) {
    return (node.parent.type === "ForOfStatement" || node.parent.type === "ForInStatement") &&
        node === node.parent.left;
}
function isLoopAssignee(node) {
    return (node.parent.type === "ForOfStatement" || node.parent.type === "ForInStatement") &&
        node === node.parent.left;
}
function isLoopAssignee ( node ) { return ( node . parent . type === "ForOfStatement" || node . parent . type === "ForInStatement" ) && node === node . parent . left ; }
Checks whether the given node is the assignee of a loop.

@param {ASTNode} node - A VariableDeclaration node to check.
@returns {boolean} `true` if the declaration is assigned as part of loop
iteration.
Checks whether the given node is the assignee of a loop .