Updating my node version to v16, I noticed many tests breaking, because
the way errors are formatted did change. This commit ensures that the
test suite keeps working for all node versions.
Before this commit, the error handling code simply destroyed the
application whenever an unhandled error occured in the owl rendering
process. This is perfectly fine, except that since the application is
potentially corrupted, the destroy code may crash as well. We simply
catch those errors to avoid shadowing the main issue.
closes#866
Before this commit, the error handling process was too naive: once an
error occurs in a rendering, owl catches it, looks for a component that
implements the catchError method, then calls it.
However, in real life, we sometimes need to rethrow that error (or
another one) to propagate the error to some parent handler. This error
needs to be handled by the closest parent component that implements
catchError.
This is what this commit implements: it wraps the catchError call in a
try/catch, then in case of errors, try to handle it by a parent.
The initial problem solved by this commit is that it was possible to get
into a situation where a mounting/rendering was started, then the component was
updated, but then another mounting operation begins, and it tries to
reuse the previous rendering operation, which is no longer uptodate.
The underlying issue is that Owl did not track properly the various
internal state change of a component. These issue should be solved by
the introduction of the status enum, which currently tracks 6 possible
states:
- CREATED
- WILLSTARTED
- RENDERED
- MOUNTED
- UNMOUNTED
- DESTROYED
This status number replaces the isMounted and isDestroyed boolean flags.
It has the advantage of making sure that the component is in a
consistent state (it is no longer possible to be destroyed and mounted,
for example)
Another advantage is that it gives us an easy way to track the fact that
a component has been rendered, but is not in the DOM. This is a subtle
situation where some various events can happen, and we need to be able
to react to that case.
Note that there is a change of behaviour: if a component is mounted in a
specific target, then before the mounting is complete, the component is
mounted in another target, we no longer reject the first mounting
operation.
In most cases, we just want Component<any, Env>. But since it was so
annoying to have always the type Env, we actually used
Component<any,any> everywhere.
With this commit, the generic types have a default (and their order is
swapped), so we can simply use Component in most cases, and
Component<Props> when we want to type the props.
Samuel Degueldre