VersionConstraint intersect()

in lib/src/version_range.dart [159:215]
43 lines of code
14 McCabe index (conditional complexity)

  VersionConstraint intersect(VersionConstraint other) {
    if (other.isEmpty) return other;
    if (other is VersionUnion) return other.intersect(this);

    // A range and a Version just yields the version if it's in the range.
    if (other is Version) {
      return allows(other) ? other : VersionConstraint.empty;
    }

    if (other is VersionRange) {
      // Intersect the two ranges.
      Version? intersectMin;
      bool intersectIncludeMin;
      if (allowsLower(this, other)) {
        if (strictlyLower(this, other)) return VersionConstraint.empty;
        intersectMin = other.min;
        intersectIncludeMin = other.includeMin;
      } else {
        if (strictlyLower(other, this)) return VersionConstraint.empty;
        intersectMin = min;
        intersectIncludeMin = includeMin;
      }

      Version? intersectMax;
      bool intersectIncludeMax;
      if (allowsHigher(this, other)) {
        intersectMax = other.max;
        intersectIncludeMax = other.includeMax;
      } else {
        intersectMax = max;
        intersectIncludeMax = includeMax;
      }

      if (intersectMin == null && intersectMax == null) {
        // Open range.
        return VersionRange();
      }

      // If the range is just a single version.
      if (intersectMin == intersectMax) {
        // Because we already verified that the lower range isn't strictly
        // lower, there must be some overlap.
        assert(intersectIncludeMin && intersectIncludeMax);
        return intersectMin!;
      }

      // If we got here, there is an actual range.
      return VersionRange(
          min: intersectMin,
          max: intersectMax,
          includeMin: intersectIncludeMin,
          includeMax: intersectIncludeMax,
          alwaysIncludeMaxPreRelease: true);
    }

    throw ArgumentError('Unknown VersionConstraint type $other.');
  }