Function mapTypesByKeyProperty

test/fixtures/snapshot/typescript.js:69447–69481

(types, name)

        // has a non-literal type or if less than 10 or less than 50% of the constituents have a unique key.
        // Entries with duplicate keys have unknownType as the value.
        function mapTypesByKeyProperty(types, name) {
            var map = new ts.Map();
            var count = 0;
            var _loop_23 = function (type) {
                if (type.flags & (524288 /* TypeFlags.Object */ | 2097152 /* TypeFlags.Intersection */ | 58982400 /* TypeFlags.InstantiableNonPrimitive */)) {
                    var discriminant = getTypeOfPropertyOfType(type, name);
                    if (discriminant) {
                        if (!isLiteralType(discriminant)) {
                            return { value: undefined };
                        }
                        var duplicate_1 = false;
                        forEachType(discriminant, function (t) {
                            var id = getTypeId(getRegularTypeOfLiteralType(t));
                            var existing = map.get(id);
                            if (!existing) {
                                map.set(id, type);
                            }
                            else if (existing !== unknownType) {
                                map.set(id, unknownType);
                                duplicate_1 = true;
                            }
                        });
                        if (!duplicate_1)
                            count++;
                    }
                }
            };
            for (var _i = 0, types_16 = types; _i < types_16.length; _i++) {
                var type = types_16[_i];
                var state_9 = _loop_23(type);
                if (typeof state_9 === "object")
                    return state_9.value;
            }
            return count >= 10 && count * 2 >= types.length ? map : undefined;
        }
        // Return the name of a discriminant property for which it was possible and feasible to construct a map of
        // constituent types keyed by the literal types of the property by that name in each constituent type.
        function getKeyPropertyName(unionType) {