Validates nested brackets

validate-brackets.js

const closing = {
    ')': '(',
    ']': '[',
    '>': '<'
};
const openBrackets = Object.values(closing)

function verify(str) {
    const bracketsCount = []
    for (let i = 0; i < str.length; i++) {
        const char = str.charAt(i);
        if(openBrackets.indexOf(char) >= 0) {
            bracketsCount.push(char)
        } else if (char in closing) {
            const openBracket = closing[char];
            if (openBracket === bracketsCount[bracketsCount.length - 1]) {
                bracketsCount.pop()
            } else {
                return 0
            }
        }
    }
    return bracketsCount.length > 0 ? 0 : 1;
}

const testVerify = () => [
    1 === verify("---(++++)----"),
    1 === verify(""),
    1 === verify("before ( middle []) after "),
    0 === verify(") ("),
    0 === verify("<(   >)"),
    1 === verify("(  [  <>  ()  ]  <>  )"),
    0 === verify("   (      [)")
].every(a => a)