// const data = `
// ---
// hello: world
// foo: bar
// ---
// hello: world
// ---

// # Some article title

// > "hello world"
// > "foo bar"
// `

const data = `
-----
hello: world

# Some article title
-----

> "hello world"
> "foo bar"
`

function getYamlSection(data) {
    let state = 0
    let lines = []
    let yamlSectionDashesLength = 0
    for (const line of data.trim().split("\n")) {
        if (state === 0) {
            if (line.length >= 3 && line === "-".repeat(line.length)) {
                state = 1
                yamlSectionDashesLength = line.length
            } else if (line.trim() !== "") {
                return ''
            }
        } else if (state === 1) {
            if (line.length === yamlSectionDashesLength && line === "-".repeat(yamlSectionDashesLength)) {
                return lines.join('\n')
            } else {
                lines.push(line)
            }
        }
    }
    return ''
}

console.log(getYamlSection(data))