Example: Is the current file being run from the shell?

[rauschma]

Suggestion: On the page https://bucklescript.github.io/docs/en/nodejs-special-variables.html , add the following example:

/**
 * Is the current file being run from the shell?
 * @param _module Call with [%bs.node _module]
 */
let isMain = (_module: option(Node.node_module)) => {
  let require: option(Node.node_require) = [%bs.node require];
  
  switch (require, _module) {
  | (Some(require'), Some(_module')) =>
    switch (Js.undefinedToOption(require'##main)) {
    | Some(main') =>
      main' === _module'
    | None => Js.Exn.raiseError("Illegal state")
    };
  | _ => Js.Exn.raiseError("Illegal state")
  };
};

Created with help from Glenn Slotte. https://reasonml.chat/t/where-are-node-module-and-node-require/191

[glennsl]

Webpage source is here btw, if you'd like to make it a PR.

[rauschma]

@glennsl Right. Let’s pause this and I’ll submit a PR with (a simplified version) of this example.