github.js

// Modified from: https://github.com/slavcodev/coverage-monitor-action

// Not needed for now, but could be useful
// const createStatus = async ({ client, context, sha, status }) =>
// 	client.repos.createCommitStatus({
// 		...context.repo,
// 		sha,
// 		...status,
// 	})

// Every comment written by our action will have this hidden
// header on top, and will be used to identify which comments
// to update/delete etc

const appendHiddenHeaderToComment = (body, hiddenHeader) => hiddenHeader + body;

const listComments = async ({ client, context, prNumber, hiddenHeader }) => {
    const { data: existingComments } =
        (await client.issues?.listComments({
            ...context.repo,
            issue_number: prNumber,
        })) || {};

    return (
        existingComments?.filter(({ body }) => body.startsWith(hiddenHeader)) ??
        []
    );
};

const insertComment = ({ client, context, prNumber, body }, hiddenHeader) =>
    client.issues?.createComment({
        ...context.repo,
        issue_number: prNumber,
        body: appendHiddenHeaderToComment(body, hiddenHeader),
    });

const updateComment = ({ client, context, body, commentId }, hiddenHeader) =>
    client.issues?.updateComment({
        ...context.repo,
        comment_id: commentId,
        body: appendHiddenHeaderToComment(body, hiddenHeader),
    });

const deleteComments = ({ client, context, comments }) =>
    Promise.all(
        comments.map(({ id }) =>
            client.issues?.deleteComment({
                ...context.repo,
                comment_id: id,
            }),
        ),
    );

export const upsertComment = async ({
    client,
    context,
    prNumber,
    body,
    hiddenHeader,
}) => {
    if (client.issues) {
        const existingComments = await listComments({
            client,
            context,
            prNumber,
            hiddenHeader,
        });
        const last = existingComments.pop();

        await deleteComments({
            client,
            context,
            comments: existingComments,
        });

        return last
            ? updateComment(
                  {
                      client,
                      context,
                      body,
                      commentId: last.id,
                  },
                  hiddenHeader,
              )
            : insertComment(
                  {
                      client,
                      context,
                      prNumber,
                      body,
                  },
                  hiddenHeader,
              );
    }

    return "";
};