pub fn render_for_args(args: &[&str]) -> Option<String>Expand description
Render the help that heddle <args> would print, in-process, for the
help-shaped argv forms — without spawning the binary.
args is the argv after the program name (e.g. ["clone", "--help"],
["help", "threads"], ["capture", "--help-agent"]). Returns Some(text)
with the exact bytes the binary writes to stdout for that request, or
None when the argv is not a pure help request this renderer serves (the
caller should fall back to spawning the binary).
This mirrors main.rs’s help-dispatch routing precisely: the bare-help
intercept, the heddle <path> --help pre-parse, the capture --help-agent
reveal, and the heddle help <topics> arm. Because the underlying printers
are now write_stdout(&render_*(..)) wrappers, the in-process text is
byte-identical to the spawned binary’s stdout — only the execution
mechanism differs (HeddleCo/heddle#381). Help is repo-, cwd-, and
env-independent, so this is safe to call from parallel tests.