Mixing chromeOptions.args cli and protractor.conf.js - google-chrome

Question

Currently we have a "standard" protractor.conf.js file in place. It has a chrome specific section which looks something like this:
capabilities: {
browserName: 'chrome',
chromeOptions: {
args: [
'--no-sandbox', '--window-size=1280,1480', '--window-position=800,0'
],
prefs: {
intl: {accept_languages: defaults.LANGUAGE},
},
},
}
When we run the tests locally, everything is fine.
On our CI Infrastructure we add via CLI call the headless option:
protractor protractor.conf.js --capabilities.chromeOptions.args='headless'
First everything looked fine. The tests were running with headless chrome. But we recognized that the --window-size=1280,1480 specified in the config file was not used. We removed the --capabilities from the cli call and added the headless option directly into the protractor.conf.js.
Everything was now also working fine on the CI Infrastructure. This means the --window-size specified in the config was recognized and used.
Further tests showed, that if we want to use the CLI arguments, we would need to also add the window-size to the CLI call, to get it working as it should.
Now the question itself:
Why is this like that ? Shouldn't it be possible to add additional chromeOptions.args via CLI call ? Are the chromeOptions.args from the config no longer respected when passing some chromeOptions.args via CLI ?

Answer 1

Yes, The CLI values will overwrite the value in conf.js.
Below is the code snippet from launcher.ts
let initFn = function(configFile: string, additionalConfig: Config) {
let configParser = new ConfigParser();
if (configFile) { // this is the protractor conf.js
configParser.addFileConfig(configFile);
}
if (additionalConfig) { // this is all cli arguments
configParser.addConfig(additionalConfig);
}
Below is the addConfig from configParser.ts
public addConfig(argv: any): ConfigParser {
this.addConfig_(argv, process.cwd());
return this;
}
private addConfig_(additionalConfig: any, relativeTo: string): void {
// All filepaths should be kept relative to the current config location.
// This will not affect absolute paths.
['seleniumServerJar', 'chromeDriver', 'firefoxPath', 'frameworkPath', 'geckoDriver',
'onPrepare']
.forEach((name: string) => {
if (additionalConfig[name] && typeof additionalConfig[name] === 'string') {
additionalConfig[name] = path.resolve(relativeTo, additionalConfig[name]);
}
});
merge_(this.config_, additionalConfig);
}
let merge_ = function(into: any, from: any): any {
for (let key in from) {
if (into[key] instanceof Object && !(into[key] instanceof Array) &&
!(into[key] instanceof Function)) {
merge_(into[key], from[key]);
} else {
into[key] = from[key];
}
}
return into;
};
Because capabilities.chromeOptions.args is Array, thus the args value in conf.js will be overwrite by value from cli in merge_ function: into[key] = from[key];
Therefor, you have to specify all chromeOptions.args from cli by using multiple --capabilities.chromeOptions.args=xxx in cli, rather than
partial.
protractor conf.js \
--capabilities.chromeOptions.args='headless' \
--capabilities.chromeOptions.args='--no-sandbox' \
--capabilities.chromeOptions.args='--window-size=1280,1480'