Function findMostOverlappyType

test/fixtures/snapshot/typescript.js:89207–89233

(source, unionTarget)

            }
        }
        function findMostOverlappyType(source, unionTarget) {
            var bestMatch;
            if (!(source.flags & (131068 /* TypeFlags.Primitive */ | 406847488 /* TypeFlags.InstantiablePrimitive */))) {
                var matchingCount = 0;
                for (var _i = 0, _a = unionTarget.types; _i < _a.length; _i++) {
                    var target = _a[_i];
                    if (!(target.flags & (131068 /* TypeFlags.Primitive */ | 406847488 /* TypeFlags.InstantiablePrimitive */))) {
                        var overlap = getIntersectionType([getIndexType(source), getIndexType(target)]);
                        if (overlap.flags & 4194304 /* TypeFlags.Index */) {
                            // perfect overlap of keys
                            return target;
                        }
                        else if (isUnitType(overlap) || overlap.flags & 1048576 /* TypeFlags.Union */) {
                            // We only want to account for literal types otherwise.
                            // If we have a union of index types, it seems likely that we
                            // needed to elaborate between two generic mapped types anyway.
                            var len = overlap.flags & 1048576 /* TypeFlags.Union */ ? ts.countWhere(overlap.types, isUnitType) : 1;
                            if (len >= matchingCount) {
                                bestMatch = target;
                                matchingCount = len;
                            }
                        }
                    }
                }
            }
            return bestMatch;
        }
        function filterPrimitivesIfContainsNonPrimitive(type) {
            if (maybeTypeOfKind(type, 67108864 /* TypeFlags.NonPrimitive */)) {
                var result = filterType(type, function (t) { return !(t.flags & 131068 /* TypeFlags.Primitive */); });