Function checkForUpdateInBackground

src/upgrade/update-check.ts:239–250

(
  deps: UpdateCheckDeps = {},
  log: (line: string) => void = (line) => process.stderr.write(line),
)

 * never blocks, never writes stdout.
 */
export function checkForUpdateInBackground(
  deps: UpdateCheckDeps = {},
  log: (line: string) => void = (line) => process.stderr.write(line),
): void {
  refreshUpdateCheck(deps)
    .then((notice) => {
      // The shared notice sentence starts with "CodeGraph …"; drop the word
      // after the log tag so the line doesn't read "[CodeGraph] CodeGraph …".
      if (notice) log(`[CodeGraph] ${notice.replace(/^CodeGraph /, '')}\n`);
    })
    .catch(() => { /* fail silent */ });
}