adding tests for CLI functionality - brainstorming

[jywarren]

Trying to think through the best way to do better CLI testing. Right now we have only: https://github.com/publiclab/image-sequencer/blob/440c3e0ad0ab081bdcc7dfff0d000f52a0902035/test/core/cli.js which is pretty non-existent.

Noting that we encountered this in #659 but did not at that time implement tests.

Ok, so I had thought this was the way to go, installing https://github.com/sstephenson/bats (blog https://medium.com/@pimterry/testing-your-shell-scripts-with-bats-abfca9bdc5b9) and comparing images like perhaps:

looksSame = require('looks-same');
looksSame(process.argv[2], process.argv[3], function(error, {equal}) {
  // equal will be true, if images looks the same
  console.log(equal ? 1 : 0);
});

But actually maybe it's just easier to use one of our existing JS tests and running our CLI tests from inside node, like this:

const { exec } = require('child_process');
var yourscript = exec('sh hi.sh',
        (error, stdout, stderr) => {
            console.log(stdout);
            console.log(stderr);
            if (error !== null) {
                console.log(`exec error: ${error}`);
            }
        });

https://stackoverflow.com/questions/44647778/how-to-run-shell-script-file-using-nodejs#44667294 has some guidance on this.

Is there a standard way to write CLI tests for commander.js?

UPDATE: yes, it looks like there are some good ways: tj/commander.js#438

[jywarren]

cc @VibhorCodecianGupta @harshkhandeparkar @blurry-x-face who've all worked on related parts of this before... hope you're well, just seeing if this seems interesting! Also @publiclab/is-reviewers @publiclab/image-sequencer-guides

[daemon1024]

@jywarren is it open to work/brainstorm on?

We can do something like

./index.js --test

and run the series of CLI tests on a new commander instance we want. ( Inspiration can be taken from how commander.js test there module themselves ( as said in the linked issue ).

[jywarren]

@daemon1024 we'd LOVE help with this. would you be interested in submitting a PR with even a simple version of this?

[daemon1024]

@jywarren i will start working on it.