Global object (window) confusion

[piotr-cz]

Describe the bug

Readme states that MatomoTracker instance may be initialized like so

import MatomoTracker from '@datapunt/matomo-tracker-js'
const MatomoInstance = new window.MatomoTracker({})

and later uses syntax without window:

import MatomoTracker from '@datapunt/matomo-tracker-js'
const MatomoInstance = new MatomoTracker({})

however latter doesn't work (at least in rollup builds) as it holds es-module wrapper {__esModule: true, default: ƒ}.

Same object is also leaking via window.MatomoTracker_1.

IMHO it's not necessary to set class on window object, as it's already exported via IIFE in rollup config.

To Reproduce
As in description

Expected behavior
When importing MatomoTracker it's possible to initialize it via new MatomoTracker({}).
The window.MatomoTracker property is available when using ES5 prebuilt bundle.min.js.

Screenshots
N/A

Desktop (please complete the following information):
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Smartphone (please complete the following information):
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Additional context
Proposed solution:

• remove code block responsible for setting global object
• to preserve semver backward compatibility release in v1.x
• fix readme so examples are consistent

When running yarn run build, rollup shows warnings related to this issue:

src/index.ts → bundle.min.js...
(!) Mixing named and default exports
https://rollupjs.org/guide/en/#output-exports
The following entry modules are using named and default exports together:
src\index.ts

Consumers of your bundle will have to use chunk['default'] to access their default export, which may not be what you want. Use `output.exports: 'named'` to disable this warning

This is caused by exporting both default and named exports together in index.ts:

export default MatomoTracker

export { types }

I wonder do we need to export types (here)?

I'd recommend removing types from index.ts and defining in package.json

{
  "main": "lib/index.js",
  "types": "lib/types.ts"
}

Related commit: c6c2324

[jonkoops]

Thanks for submitting this issue @piotr-cz. I agree the documentation is quite confusing on this matter. I am adding this to the milestone for the next version where we intend to remove the global variable and only use the module version.

[piotr-cz]

Thanks,
so for now all examples in readme except bundleshould use new window.MatomoTracker instantiation style

[jonkoops]

Correct, and in the next version we will get rid of window.MatomoTracker entirely.

[piotr-cz]

There are more problems with window.MatomoTracker:

• when using rollup, it treats properties on window object as global dependency and doesn't include in builds
• when using terser, it tends to shorten property name to for example window.jt.default

[piotr-cz]

Probably fixed by #196 and #197