Migrate to a k6/js.modules.Module (ModulesV2)

[olegbespalov]

What?

In the k6 we deprecated, the usage of the old modules API and in the middle of the process of the migration to a new ModulesV2 API.

To do that, we need to clean up the usages of the deprecated methods:

grep --exclude-dir=vendor -Ri "common.Bind" .                   
./loki.go:	return common.Bind(
./loki.go:	return common.Bind(rt, &Client{
./loki.go:	return common.Bind(rt, &config.Labels, ctxPtr)

grep --exclude-dir=vendor -ER "With(State|InitEnv|Runtime)\(" ./
./batch_test.go:	ctx = lib.WithState(ctx, state)
./batch_test.go:	ctx = lib.WithState(ctx, state)

A good starting point can be our guide Create an extension.

Why?

The traditional approach of initializing JS modules involves calling common.Bind() on any objects that need to be exposed to JS. This method has a few technical issues we want to improve and isn't flexible enough to implement new features like giving extensions access to internal k6 objects.

[chaudum]

Changed with #22

[mstoykov]

This will actually be fixed in #28. #22 was fixing a different API breakage :(