Function invalidXRangeOrder

classes/range.js:280–283

(M, m, p)

const isX = id => !id || id.toLowerCase() === 'x' || id === '*'

const invalidXRangeOrder = (M, m, p) => (
  (isX(M) && !isX(m)) ||
  (isX(m) && p && !isX(p))
)

// ~, ~> --> * (any, kinda silly)
// ~2, ~2.x, ~2.x.x, ~>2, ~>2.x ~>2.x.x --> >=2.0.0 <3.0.0-0