setTagsContext doesn't set tags properly

What is the current behavior?

When using Raven.setTagsContext to set tags in a global context, they are not properly passed to Sentry, and an error shows up in the error report stating Discarded invalid value for parameter 'tags'

What is the expected behavior?

The error report correctly shows up in Sentry.

Which versions of Raven.js, and which browser and OS are affected by this issue? Did this work in previous versions of Raven.js? Are you using the CDN (http://ravenjs.com)? Are you using hosted Sentry or on-premises? If on-premises, which version (e.g. 8.7.0)?

Following code reproduces this error, using hosted Sentry:

Raven.config("https://{public_key}@sentry.io/{app_id}").install()
Raven.setTagsContext({ release: "test version" });

throw new Error();

[kamilogorek]

@Valandur also for the reference, here’s a list of protected tags – 'release', 'dist', 'user', 'filename', 'function' – https://github.com/getsentry/sentry/blob/master/src/sentry/tagstore/base.py#L19-L22

[kamilogorek]

That’s exactly what’s happening. I’ll try to send a PR to create more meaningful message so it’s more obvious next time 😃