ua-parser / uap-ref-impl Goto Github PK

@tobie: How do you expect the tests in uap-core to run? Do you prefer a download of the relevant files first or do you think including as a sub-project is more favorable?

I'm not sure if this is the right place to ask this question since it affects multiple implementations, including this. I cross-posted to the uap-core project but sharing here just in case it is a bug with the specific implementation.

Background

There are certain user-agents where it is not possible to derive or infer the device family, brand or model from the user-agent alone.

In our application, we want to explicitly distinguish between user-agents we recognise but we don't know of the device family (which we want to output as an empty string), and user-agents we don't recognise (fallback to the "Other" value as defined in the specification).

We've observed a difference between the uap-ref-impl Javascript and uap-csharp C# implementations of ua-parser.

Even though the Javascript is described as the "reference" implementation, we're not sure if this is a bug or the intention of the specification since it is vague about how to handle a replacement value that is an empty string "".

The specification writes,

In case that no replacement for a match is given, the first match defines the family and the model. If a *_replacement string is specified it shall overwrite or replace the match.

One could interpret "no replacement" to mean either

• undefined or null
• undefined or null or empty string

Repro

The regex YAML is defined as

device_parsers:
  - regex: '(radiocomandroid)'
    brand_replacement: ''
    device_replacement: ''
    model_replacement: ''

Testing with the user-agent string of radiocomandroid

The Javascript implementation outputs

{
    "family": "radiocomandroid",
    "brand": null,
    "model": "radiocomandroid"
}

The C# implementation outputs

{
    "IsSpider": false,
    "Brand": "",
    "Family": "",
    "Model": ""
}

Side-by-side

Question

The JavaScript implementation uses a conditional (ternary) operator which will treat an empty string "" as false, which means it will fallback to the first match value.

The C# implementation uses a == null condition which will use an empty string "" as the final value.

https://github.com/ua-parser/uap-csharp/blob/master/UAParser/UAParser.cs#L523

Which of these implementations is the intent of the specification? Is an empty string considered "no replacement"?

is this the source of npm's ua-parser package?
https://www.npmjs.com/package/ua-parser

and why is the version https://github.com/ua-parser/uap-ref-impl/blob/master/package.json#L5
is lower then https://github.com/tobie/ua-parser/blob/master/package.json#L5?

The current version on npm is v0.1.0

$ npm info uap-ref-impl | grep version:
  version: '0.1.0',

The present is v0.2.0.
Can you please perform a npm publish?
Thanks

@tobie Can you please add initial projects to "/ua-parser" for all the other languages in order to fork these "language" projects and issue PRs?

Replaces should be supported with other, high detail fields too, just family isn't enough