thanks for pointing me in the right direction, that fixed the zxing issue and I was also able to suppress another warning I was seeing,
WARN [array-observation] Detected 2nd attempt of patching array from Aurelia binding. This is probably caused by dependency mismatch between core modules and a 3rd party plugin. Please see https://github.com/aurelia/cli/pull/906 if you are using webpack.
"moduleNameMapper": {
"^aurelia-binding$": "<rootDir>/node_modules/aurelia-binding/dist/commonjs/aurelia-binding.js"
},
seemed to fix it.