d3-sankey-diagram/test/compareSVGPath.js

Sankey diagram d3 plugin

/* Compare SVG paths */

export default function compareSVGPath (t, actual, expected, message) {
  const { equal, i, x, y, wrongLengths } = pathEqual(actual, expected)
  if (equal) {
    t.pass(message)
  } else if (wrongLengths) {
    t.fail(message + `: Different lengths: "${actual}" != "${expected}"`)
  } else {
    t.fail(message + `: Mismatch at position ${i}: "${x}" != "${y}"`)
  }
}

/* from d3: test/assert.js */
function pathEqual (a, b, tol = 1e-3) {
  a = parsePath(a.replace(/\s+/g, ' '))
  b = parsePath(b.replace(/\s+/g, ' '))
  const n = a.length; let i = -1; let x; let y
  if (n !== b.length) { return { equal: false, x: a.slice(Math.min(n, b.length)), y: b.slice(Math.min(n, b.length)), wrongLengths: true } }
  while (++i < n) {
    x = a[i]
    y = b[i]
    if (typeof x === 'string') {
      if (x !== y) return { equal: false, i, x, y }
    } else if (typeof y !== 'number') {
      return { equal: false, i, x, y }
    } else if (Math.abs(x - y) > tol) {
      return { equal: false, i, x, y }
    }
  }
  return { equal: true }
}

const reNumber = /[-+]?(?:\d+\.\d+|\d+\.|\.\d+|\d+)(?:[eE][-]?\d+)?/g

function parsePath (path) {
  const parts = []
  reNumber.lastIndex = 0
  let s0 = 0
  // eslint-disable-next-line no-cond-assign
  for (let i = 0, m; m = reNumber.exec(path); ++i) {
    if (m.index) {
      const part = path.substring(s0, m.index)
      if (!/^[, ]$/.test(part)) parts.push(part)
    }
    parts.push(parseFloat(m[0]))
    s0 = reNumber.lastIndex
  }
  if (s0 < path.length) parts.push(path.substring(s0))
  return parts
}

export function formatPath (path) {
  return path.replace(reNumber, formatNumber)
}

function formatNumber (s) {
  return Math.abs((s = +s) - Math.floor(s)) < 1e-3
    ? Math.floor(s)
    : s.toFixed(3)
}