export function declare(builder) {

return (api, options, dirname) => {
  if (!api.assertVersion) {
    // Inject a custom version of 'assertVersion' for Babel 6 and early
    // versions of Babel 7's beta that didn't have it.
    api = Object.assign(copyApiObject(api), {
      assertVersion(range) {
        throwVersionError(range, api.version);
      },
    });
  }

  return builder(api, options || {}, dirname);
};

}

function copyApiObject(api) {

// Babel >= 7 <= beta.41 passed the API as a new object that had
// babel/core as the prototype. While slightly faster, it also
// means that the Object.assign copy below fails. Rather than
// keep complexity, the Babel 6 behavior has been reverted and this
// normalizes all that for Babel 7.
let proto = null;
if (typeof api.version === "string" && /^7\./.test(api.version)) {
  proto = Object.getPrototypeOf(api);
  if (
    proto &&
    (!has(proto, "version") ||
      !has(proto, "transform") ||
      !has(proto, "template") ||
      !has(proto, "types"))
  ) {
    proto = null;
  }
}

return {
  ...proto,
  ...api,
};

}

function has(obj, key) {

return Object.prototype.hasOwnProperty.call(obj, key);

}

function throwVersionError(range, version) {

if (typeof range === "number") {
  if (!Number.isInteger(range)) {
    throw new Error("Expected string or integer value.");
  }
  range = `^${range}.0.0-0`;
}
if (typeof range !== "string") {
  throw new Error("Expected string or integer value.");
}

const limit = Error.stackTraceLimit;

if (typeof limit === "number" && limit < 25) {
  // Bump up the limit if needed so that users are more likely
  // to be able to see what is calling Babel.
  Error.stackTraceLimit = 25;
}

let err;
if (version.slice(0, 2) === "7.") {
  err = new Error(
    `Requires Babel "^7.0.0-beta.41", but was loaded with "${version}". ` +
      `You'll need to update your @babel/core version.`,
  );
} else {
  err = new Error(
    `Requires Babel "${range}", but was loaded with "${version}". ` +
      `If you are sure you have a compatible version of @babel/core, ` +
      `it is likely that something in your build process is loading the ` +
      `wrong version. Inspect the stack trace of this error to look for ` +
      `the first entry that doesn't mention "@babel/core" or "babel-core" ` +
      `to see what is calling Babel.`,
  );
}

if (typeof limit === "number") {
  Error.stackTraceLimit = limit;
}

throw Object.assign(
  err,
  ({
    code: "BABEL_VERSION_UNSUPPORTED",
    version,
    range,
  }: any),
);

}