karma-browserstack-config

This is a package that helps managing the configuration of BrowserStack browsers in Karma.

In most of my karma.conf.js files, I end up with a section going:

customLaunchers: {
      ChromeWin: {
        base: "BrowserStack",
        browser: "Chrome",
        os: "Windows",
        os_version: "10",
      },
      FirefoxWin: {
        base: "BrowserStack",
        browser: "Firefox",
        os: "Windows",
        os_version: "10",
      },
      // ... lots of other browsers.
}

That's a lot of boilerplate. For one thing, most of the information there is not stuff I need to revise often. It is also error-prone. I recently discovered I had a setup for running opera in Windows twice in the same configuration. I had OperaWin and Opera. They were far enough apart that the duplication was not evident.

So I figured I could help reduce mistakes with a library I'd use from project to project, and here we are. It is probably somewhat idiosyncratic. Note that this library is meant to help with common usage scenarios. If you need to pass unusual flags into a configuration sent to BrowserStack, you'll need add the flags to the configuration produced by this library.

ConfigBuilder

The documentation here gives an overview of what can be done with this library. For the gory details, read the jsdoc comments in the source code. They are more likely to be up to date and give you all the details and gotchas than the documentation here.

You get configurations from ConfigBuilder. Here's an example of a fragment of karma.conf.js that uses ConfigBuilder to get configurations for all browsers known to this package, with the exception of IE browsers and Safari9:

const { ConfigBuilder } = require("karma-browserstack-config");

module.exports = function configure(config) {
  const customLaunchers = new ConfigBuilder().getConfigs({
    excludes: [/^IE/, "Safari9"],
  });

  config.set({
    customLaunchers
    ...
  });
};

You create a new builder with new ConfigBuilder(). You can pass an object with these options:

• base specifies a the value of the base field for all configurations produced.

• prefix adds a prefix in front of all the keys in the returned object.

• mobile when true requires that mobile devices be included in the list of configurations.

The getConfigs call returns an object ready to be used as customLaunchers. This call takes an object with two fields:

• includes specifies configurations to include in the returned object. It can be the string "all" to include all or an array of strings.

• excludes specifies configurations to exclude. It is an array of strings or regular expressions.

It is also possible to just pass a the "all" string to include everything.

Examples:

• getConfigs("all") returns an object with all configurations.

• getConfigs({ excludes: [/^IE/] }) excludes all IE configurations.

Here is the list of keys that are defined. If a key does not have a version number then it runs the latest version of the browser.

• ChromeWin
• FirefoxWin
• OperaWin
• Edge
• IE11, IE10, IE9, IE8.
• Safari12, Safari11, Safari10, ``Safari9`.

lintConfig

This package also provides a lintConfig function. You pass to it what you want to put in your customLaunchers. It will run checks on the configuration and immediately throw if an error is encountered. It currently checks that:

• The configuration object is not empty.

• The configuration object does not contain duplicates. Duplication happens when you have two different keys with the same configuration parameters. "Same" here is determined by a deep-equal comparison. This check is motivated by a real mistake I had in one of my configurations, I had the keys OperaWin and Opera which started the same browser. There was nothing in the pipeline that detected the duplication and the tests were run against the same browser twice. Big waste of resources.