Error when using a property

Currently plugin lets you declare properties, but will trigger an error on access.

Simple test case:
var a = {
b_c: 'a' // valid
};
a.b_c = 2; // error

Start by locating the JavaScript ESLint rule that reports property-name errors and reproduce the example with the rule enabled. Update the behavior so declaring and accessing the b_c property does not trigger an error, then verify the example through the repository's available checks.

Written by the indexing model from the issue text.