Function checkoutBranch

src/utils/teleport.tsx:251–282

* Checks out a specific branch

(branchName: string)

 * Checks out a specific branch
 */
async function checkoutBranch(branchName: string): Promise<void> {
  // First try to checkout the branch as-is (might be local)
  let {
    code: checkoutCode,
    stderr: checkoutStderr
  } = await execFileNoThrow(gitExe(), ['checkout', branchName]);

  // If that fails, try to checkout from origin
  if (checkoutCode !== 0) {
    logForDebugging(`Local checkout failed, trying to checkout from origin: ${checkoutStderr}`);

    // Try to checkout the remote branch and create a local tracking branch
    const result = await execFileNoThrow(gitExe(), ['checkout', '-b', branchName, '--track', `origin/${branchName}`]);
    checkoutCode = result.code;
    checkoutStderr = result.stderr;

    // If that also fails, try without -b in case the branch exists but isn't checked out
    if (checkoutCode !== 0) {
      logForDebugging(`Remote checkout with -b failed, trying without -b: ${checkoutStderr}`);
      const finalResult = await execFileNoThrow(gitExe(), ['checkout', '--track', `origin/${branchName}`]);
      checkoutCode = finalResult.code;
      checkoutStderr = finalResult.stderr;
    }
  }
  if (checkoutCode !== 0) {
    logEvent('tengu_teleport_error_branch_checkout_failed', {});
    throw new TeleportOperationError(`Failed to checkout branch '${branchName}': ${checkoutStderr}`, chalk.red(`Failed to checkout branch '${branchName}'\n`));
  }

  // After successful checkout, ensure upstream is set
  await ensureUpstreamIsSet(branchName);
}

/**
 * Gets the current branch name