Protractor CLI rejects `cucumberOpts` as invalid

[jan-molak]

Hello there!

It looks like the whitelist defined in the cli.ts rejects the cucumberOpts key which the protractor-cucumber-framework uses.

• Node Version: 6.9.4
• Protractor Version: 5.0.0

Running protractor with the below config file results in this output:

Error: Found extra flags: cucumberOpts

exports.config = {
    seleniumServerJar: path.resolve(node_modules, 'protractor/node_modules/webdriver-manager/selenium/selenium-server-standalone-2.53.1.jar'),
        
    framework: 'custom',
    frameworkPath: require.resolve('protractor-cucumber-framework'),
    specs: [ 'features/**/*.feature' ],
    cucumberOpts: {
        require:    [
            'features/**/*.ts'
        ],
        format:     'pretty',
        compiler:   'ts:ts-node/register',
    }
};

I guess there are several ways to resolve this issue:

1. run the protractor/cucumber combo with a --disableChecks switch (that's more of a workaround, though)
2. change the whitelist to include cucumberOpts, which allows people to run their cucumber tests same as they used to, but requires the Protractor Team to amend the whitelist whenever a new framework comes along or changes the way it's configured (which breaks "half of SOLID" ;-))
3. change the CLI to only perform the checks on keys recognised and supported by Protractor, ignoring any additional keys, which to me seems the most sensible approach.

Looking forward to hearing your thoughts!
Jan

[heathkit]

The goal of the flag checks is to help catch when people misspell a flag name, so ignoring additional keys would defeat the purpose. However, there should be a way for protractor-cucumber-framework to add to the whitelist, we can work on that.

[jan-molak]

I guess there could be an API to allow plugin authors to register additional commands perhaps?

[igniteram]

@jan-molak This is strange you should not face this issue. Are you sure you are not passing cucumberOpts flag through command line?

As you see protractor's config interface was recently updated to support any optional key i.e. it allows us to use cucumberOpts with minimal dependencies. Coming to new changes to protractor's CLI, I agree with @mgiambalvo ignoring additional flags would not help users know the protractor's actual cli commands.
If you want to use your custom flag you would have to use --disableChecks flag.

But since you are passing cucumberOpts in config itself you should not get this issue. I have been using this setup and did not face any issues.

For your reference also pls check protractor-cookbook protractor-typescript-cucumber example which was recently upgraded to Protractor 5.0 with no issues.

[jan-molak]

Thanks @igniteram, I didn't realise the behaviour is different when the option is specified on the command line.

Now that you pointed that out it might be relevant that I'm doing both:

• I set the cucumberOpts in the protractor config file to register ts-node
• I pass the cucumberOpts.name flag to run a specific test

A complete example to demonstrate the behaviour I'm seeing would be this:

// protractor.conf.js

exports.config = {
    seleniumServerJar: path.resolve(node_modules, 'protractor/node_modules/webdriver-manager/selenium/selenium-server-standalone-2.53.1.jar'),
        
    framework: 'custom',
    frameworkPath: require.resolve('protractor-cucumber-framework'),
    specs: [ 'features/**/*.feature' ],
    cucumberOpts: {
        require:    [
            'features/**/*.ts'
        ],
        format:     'pretty',
        compiler:   'ts:ts-node/register',
    }
};

// package.json

{
  // ...
  "scripts": {
    "pree2e": "npm run webdriver:update -- --standalone",
    "e2e": "protractor ./protractor.conf.js",
    "e2e-single": "protractor ./protractor.conf.js --cucumberOpts.name",
    "webdriver-manager": "webdriver-manager",
    "webdriver:update": "npm run webdriver-manager update",
    // ...
  }
}

Now, although running npm run e2e (without specifying the cucumberOpts.name on the command line) works fine, running the e2e-single results in an error:

npm run e2e-single "Subtract two numbers"

/some/path/node_modules/protractor/built/cli.js:172
        throw new Error('Found extra flags: ' + unknownKeys.join(', '));
        ^

Error: Found extra flags: cucumberOpts
    at Object.<anonymous> (/some/path/node_modules/protractor/built/cli.js:172:15)

I suppose this means that the issue still stands, but thanks to your suggestion it can be narrowed down to the CLI rather than the config. Thanks!

[igniteram]

@jan-molak This is expected behaviour! since protractor 5.0, there is a check for unidentified command line flags, i.e. it would throw the above error if you use any flag which is not part of protractor's command line options which can be found here .

You could see that cucumberOpts doesn't belong to the list of identified command line flags in protractor, so in case you are passing this as a custom flag, as I said earlier you have to use --disableChecks flag along with this. So in your case you would have to do this-

"e2e-single": "protractor ./protractor.conf.js --cucumberOpts.name --disableChecks"

Now your script should run successfully, The job of disableChecks flags is to ignore any unidentified flags just as it was working in the earlier versions.

In the next version of protractor you would get a better error message for these scenarios. I hope this clarifies your query!

[jan-molak]

Thank you for getting back to me so quickly!

If I may make a suggestion, perhaps allowing plugin authors to register additional flags for the CLI and configuration options for the protractor.conf.js via the plugin API might be a nice way of avoiding having to specify the --disableChecks, which, granted, gets rid of the warning, but also disables other, potentially useful checks?

This way the white list we discussed earlier could stay as it is, but optionally get expanded via plugins.

Looking forward to hearing your thoughts!

[igniteram]

Expanding the white list via plugin api should be a viable option in future.

@cnishina what are your thoughts on it? you are the right person here 😄

[heathkit]

There might be a better way to do this that we could do in the future. In the meantime, #3994 will allow frameworks to specify extra flags that they accept in the call to runTestPreparer().

This should go out in Protractor 5.1