Should throw if specversion attribute is missing

[satazor]

Describe the Bug

Does not throw if event doesn't have a specversion attribute, and fallbacks to 1.0. The spec says that the specversion attribute is mandatory, so I think this library should fail when it's missing, instead of "magically" falling back.

Steps to Reproduce

1. Receiver.accept({ 'Content-Type': 'application/cloudevents+json' }, { id: 'foo', source: 'foo', type: 'foo' });
2. Prints console.error saying it will fallback to 1.0
3. Validation passes

Expected Behavior
It should throw, since the specversion attribute is missing

[satazor]

https://runkit.com/embed/chsthvg529ba

[lance]

@satazor thanks for pointing this out. I will look into dealing with this in #328

[lance]

@satazor in this PR, there was discussion around loose validation on receipt of a CloudEvent. Based on input from the community, noted in that comment, receipt of a CloudEvent should have loose validation, since it should be possible to receive and recover from poorly formed/invalid events. The example you provide is when receiving events on the wire - just such a scenario. If you would like to check whether the received event is valid, you can call CloudEvent#validate().

That method returns a boolean. I think it might be nice to see what the validation errors actually were, and we don't really have a convenience function for that. In any case, this is expected behavior.

[lance]

Oh - but I see the problem here. Since it's defaulting the specversion, property, by the time it's unmarshalled as a CloudEvent, it is valid, so calling ce.validate() won't help.

[lance]

The other required attribute that we supply a default for if it's not provided is id. The same would happen for this.

[github-actions]

This issue is stale because it has been open 30 days with no activity.

[lholmquist]

I know this has been open for a while, but the idea is that we shouldn't be defaulting the specversion and id fields?

This would be a good one to get into the 4.0 release. i can assign myself to take of it

[lance]

I know this has been open for a while, but the idea is that we shouldn't be defaulting the specversion and id fields?

I think defaulting them on creation with new CloudEvent() is fine. But when receiving events, we should not just assume that they are v1.0. That's what we are doing here.

sdk-javascript/src/message/http/index.ts

Lines 58 to 60 in f6be285

	if (version !== Version.V03 && version !== Version.V1) {
	console.error(`Unknown spec version ${version}. Default to ${Version.V1}`);
	version = Version.V1;

Throwing here would also remove that console.error() and resolve #333

[lholmquist]

@lance that sounds good. i'll take of it