Get the common ancestor between two commits

type Bitbucket = {

  username: string;

  password: string;

};

/**

 * Get the common ancestor between two commits

 * Returns the best common ancestor between two commits, specified in a revspec

of 2 commits (e.g. 3a8b42..9ff173).

If more than one best common ancestor exists, only one will be returned. It is

unspecified which will be returned.

 */

export async function main(

  auth: Bitbucket,

  repo_slug: string,

  revspec: string,

  workspace: string

) {

  const url = new URL(

    `https://api.bitbucket.org/2.0/repositories/${workspace}/${repo_slug}/merge-base/${revspec}`

  );

  const response = await fetch(url, {

    method: "GET",

    headers: {

      Authorization: "Basic " + btoa(`${auth.username}:${auth.password}`),

    },

    body: undefined,

  });

  if (!response.ok) {

    const text = await response.text();

    throw new Error(`${response.status} ${text}`);

  }

  return await response.json();

}