CisTrans.prototype.isGeomStereoBond = function()

in packages/ketcher-core/src/domain/serializers/smi/cis_trans.js [108:191]
61 lines of code
26 McCabe index (conditional complexity)

CisTrans.prototype.isGeomStereoBond = function (bondIdx, substituents) {
  // eslint-disable-line max-statements
  // it must be [C,N,Si]=[C,N,Si] bond
  const bond = this.molecule.bonds.get(bondIdx);

  if (bond.type !== Bond.PATTERN.TYPE.DOUBLE) return false;

  const label1 = this.molecule.atoms.get(bond.begin).label;
  const label2 = this.molecule.atoms.get(bond.end).label;

  if (label1 !== 'C' && label1 !== 'N' && label1 !== 'Si' && label1 !== 'Ge') {
    return false;
  }
  if (label2 !== 'C' && label2 !== 'N' && label2 !== 'Si' && label2 !== 'Ge') {
    return false;
  }

  // the atoms should have 1 or 2 single bonds
  // (apart from the double bond under consideration)
  const neiBegin = this.getNeighbors.call(this.context, bond.begin);
  const neiEnd = this.getNeighbors.call(this.context, bond.end);

  if (
    neiBegin.length < 2 ||
    neiBegin.length > 3 ||
    neiEnd.length < 2 ||
    neiEnd.length > 3
  ) {
    return false;
  }

  substituents[0] = -1;
  substituents[1] = -1;
  substituents[2] = -1;
  substituents[3] = -1;

  let i;
  let nei;

  for (i = 0; i < neiBegin.length; i++) {
    nei = neiBegin[i];

    if (nei.bid === bondIdx) continue; // eslint-disable-line no-continue

    if (this.molecule.bonds.get(nei.bid).type !== Bond.PATTERN.TYPE.SINGLE) {
      return false;
    }

    if (substituents[0] === -1) substituents[0] = nei.aid;
    // (substituents[1] === -1)
    else substituents[1] = nei.aid;
  }

  for (i = 0; i < neiEnd.length; i++) {
    nei = neiEnd[i];

    if (nei.bid === bondIdx) continue; // eslint-disable-line no-continue

    if (this.molecule.bonds.get(nei.bid).type !== Bond.PATTERN.TYPE.SINGLE) {
      return false;
    }

    if (substituents[2] === -1) substituents[2] = nei.aid;
    // (substituents[3] == -1)
    else substituents[3] = nei.aid;
  }

  if (
    substituents[1] !== -1 &&
    this.samesides(bond.begin, bond.end, substituents[0], substituents[1]) !==
      -1
  ) {
    return false;
  }
  if (
    substituents[3] !== -1 &&
    this.samesides(bond.begin, bond.end, substituents[2], substituents[3]) !==
      -1
  ) {
    return false;
  }

  return true;
};