Function getSupertypeOrUnion

test/fixtures/snapshot/typescript.js:67381–67388

(types)

        // of those literal types. Otherwise, return the leftmost type for which no type to the
        // right is a supertype.
        function getSupertypeOrUnion(types) {
            if (types.length === 1) {
                return types[0];
            }
            return literalTypesWithSameBaseType(types) ?
                getUnionType(types) :
                ts.reduceLeft(types, function (s, t) { return isTypeSubtypeOf(s, t) ? t : s; });
        }
        function getCommonSupertype(types) {
            if (!strictNullChecks) {
                return getSupertypeOrUnion(types);