async function prepareWorkingBranchForJunie()

in src/github/operations/branch.ts [124:231]
96 lines of code
22 McCabe index (conditional complexity)

async function prepareWorkingBranchForJunie(context: JunieExecutionContext, octokit: Octokits): Promise<BranchInfo> {
    let baseBranch = context.inputs.baseBranch || context.payload.repository.default_branch
    let prBaseBranch: string | undefined;
    const entityNumber = context.entityNumber;
    const isPR = context.isPR;
    const createNewBranchForPR = context.inputs.createNewBranchForPR;
    const fetchDepth = context.inputs.resolveConflicts || isReviewOrCommentHasResolveConflictsTrigger(context) ? undefined : 20

    if (isPR && entityNumber) {
        let sourceBranch: string
        let state: string;
        let prAuthor: string;
        if (isPullRequestEvent(context)
            || isPullRequestReviewEvent(context)
            || isPullRequestReviewCommentEvent(context)) {
            baseBranch = context.payload.pull_request.base.ref;
            sourceBranch = context.payload.pull_request.head.ref;
            state = context.payload.pull_request.state;
            prAuthor = context.payload.pull_request.user.login;
        } else {
            try {
                const data = (await octokit.rest.pulls.get({
                    owner: context.payload.repository.owner.login,
                    repo: context.payload.repository.name,
                    pull_number: entityNumber,
                })).data;
                baseBranch = data.base.ref;
                sourceBranch = data.head.ref
                state = data.state;
                prAuthor = data.user.login;
            } catch (error) {
                const repoFullName = `${context.payload.repository.owner.login}/${context.payload.repository.name}`;
                throw new Error(
                    `❌ Failed to fetch PR #${entityNumber} information from ${repoFullName}. ` +
                    `This could be due to:\n` +
                    `• PR #${entityNumber} does not exist\n` +
                    `• Insufficient token permissions (needs 'repo' or 'pull_requests:read' scope)\n` +
                    `• GitHub API rate limits\n` +
                    `Original error: ${error instanceof Error ? error.message : String(error)}`
                );
            }
        }

        console.log(`Base branch: ${baseBranch}`);
        console.log(`Target branch: ${sourceBranch}`);

        const useExistingBranch = shouldUseExistingPRBranch(
            context.inputs.silentMode,
            createNewBranchForPR,
            context.actor,
            prAuthor,
            context.tokenOwner.login,
            state
        );

        await ensureBranchHistory(baseBranch, fetchDepth);
        await ensureBranchHistory(sourceBranch, fetchDepth);

        if (useExistingBranch) {
            try {
                await $`git checkout -B ${sourceBranch} origin/${sourceBranch}`;

                console.log(`✓ Successfully checked out PR branch for PR #${entityNumber}`);

                return {
                    baseBranch: baseBranch,
                    workingBranch: sourceBranch!,
                    isNewBranch: false,
                };
            } catch (error) {
                throw new Error(
                    `❌ Failed to checkout existing PR branch "${sourceBranch}" for PR #${entityNumber}. ` +
                    `This could be due to:\n` +
                    `• Branch "${sourceBranch}" does not exist or was deleted\n` +
                    `• Insufficient permissions to fetch from the repository\n` +
                    `• Network connectivity issues\n` +
                    `• Git authentication problems\n` +
                    `Original error: ${error instanceof Error ? error.message : String(error)}`
                );
            }
        } else {
            console.log(`Creating new branch for PR #${entityNumber} based on ${sourceBranch}`);
            prBaseBranch = baseBranch;
            baseBranch = sourceBranch;
        }
    }

    if (isPushEvent(context)) {
        baseBranch = context.payload.ref.replace("refs/heads/", "");
        console.log(`Push event detected, base branch: ${baseBranch}`);
    }

    if (!context.inputs.silentMode) {
        const entityType = isPR ? "pr" : entityNumber ? "issue" : "run";
        const branchName = `${WORKING_BRANCH_PREFIX}${entityType}${entityNumber ? `-${entityNumber}` : ""}-${context.runId}`;

        return await createNewBranch(baseBranch, branchName, prBaseBranch)
    }

    await $`git checkout -B ${baseBranch} origin/${baseBranch}`;

    return {
        baseBranch: baseBranch,
        workingBranch: baseBranch,
        isNewBranch: false,
        prBaseBranch
    }
}