src/language-js/print/type-annotation.js/printTypeAlias
function printTypeAlias(path, options, print) {
  const semi = options.semi ? ";" : "";
  const node = path.getValue();
  const parts = [];
  if (node.declare) {
    parts.push("declare ");
  }
  parts.push("type ", print("id"), print("typeParameters"));
  const rightPropertyName =
    node.type === "TSTypeAliasDeclaration" ? "typeAnnotation" : "right";
  return [
    printAssignment(path, options, print, parts, " =", rightPropertyName),
    semi,
  ];
}