Running polymer-3.x test in headless browser

Question

I want to run tests without the browser pop-up.Installed wct-headless and configured wct.config.json as shown

{
  "plugins": {
    "local": {
      "disabled": true
    },
    "headless": {
      "browsers": [
        "chrome",
        "firefox"
      ],
      "browsersOptions": {
        "chrome": [
          "headless",
          "disable-gpu",
          "no-sandbox"
        ],
        "firefox": [
          "--headless"
        ]
      }
    },
    "sauce": false,
    "xunit-reporter": {
      "output": "testfile.xml"
    }
  }
}

While executing polymer test, it gives following error

Could not find WCT plugin named "headless"

package.json

"dependencies": {
  "@polymer/polymer": "^3.0.0"
},
"devDependencies": {
  "@polymer/iron-demo-helpers": "^3.0.0-pre.19",
  "@webcomponents/webcomponentsjs": "^2.0.0",
  "wct-browser-legacy": "^1.0.0",
  "wct-headless": "^2.2.2",
  "web-component-tester": "^6.8.0",
  "wct-xunit-reporter": "1.0.2"
}

How should i configure wct.conf.json ??

Answer 1

No need to install wct-headless. Just create file wct.conf.json with the following content:

{
 "plugins": {
   "local": {
     "browsers": [
       "chrome",
       "canary",
       "firefox"
     ],
     "browserOptions": {
       "chrome": [
         "headless",
         "disable-gpu",
         "start-maximized",
         "user-agent='Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3239.108 Safari/537.36'"
       ],
       "canary": [
         "headless",
         "disable-gpu",
         "start-maximized",
         "user-agent='Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3239.108 Safari/537.36'"
       ],
       "firefox": [
         "-headless"
       ]
     } // browserOptions
   } // local
 } // plugins
}