Add auto-detection of args when node evaluating script code on command-line

[shadowspawn]

Pull Request

Problem

program.parse() will not detect the user arguments correctly when script supplied with node --print "script..." or node --eval "script...".

See: #2163

% node --eval 'const { program } = require("./index.js"); console.log(program.parse().args);' 1 2 3                                            develop
[ '2', '3' ]

Solution

Look for the relevant options in process.execArgv to detect these special cases.

References:

• https://nodejs.org/docs/latest/api/process.html#processexecargv
• https://nodejs.org/docs/latest/api/cli.html#options

% node --eval 'const { program } = require("./index.js"); console.log(program.parse().args);' 1 2 3                                  feature/node-repl
[ '1', '2', '3' ]

ChangeLog

• add: auto-detect special node flags node --eval and node --print when call .parse() with no arguments

[shadowspawn]

I am thinking the "node" mode should be smart about eval/print too, since it is a node behaviour, and would be quite like the "electron" behaviour.

And being more explicit in the README that no arguments is the auto-detect mode and "node" is the default if arguments are supplied.

And whether changing explicit "node" mode may make it a breaking semver-major change for the few people who have already coded it themselves. 😢 I think perhaps so, since the README is quite explicit about the existing behaviour:

'node': default, argv[0] is the application and argv[1] is the script being run, with user parameters after that

[shadowspawn]

I decided I am happy with the full-auto just when Commander is deciding everything!

Supplied arguments means we don't know where they came from, so play safe and assume normal node.

Did big rework of docs. Might be overkill for the JSDoc/TSDoc, but parse is a fundamental method to get right. (Could trim it down if too much!)