* Move mutation processing into it's own object.
This should stand on it's own as a refactor, but is intended as a basis
for exposing the new MutationBuffer object to further outside control e.g.
to 'mute' or batch up mutation emission when the page becomes inactive
from a https://developer.mozilla.org/en-US/docs/Web/API/Page_Visibility_API
point of view
* The `processMutations` function needed to be bound to the `mutationBuffer` object, as otherwise `this` referred to the `MutationObserver` object itself
* Neglected to add this output of `npm run typings`
* Get around the binding problem by using Arrow function expressions
* Prettier formatting
* refactoring play, pause, resume, load style sheet to subscribe style code
* support live mode in state machine
* 1. upgrade @xstate/fsm
2. add toggle interact methods to the player
There are some long-term issues in rrweb's mutation observer.
A scenario cause problem:
A list of DOM node: n1, n2, n3, n4, n5
Steps of modifying the nodes:
1. remove n1, n2, n3, n4 sequentially
2. append n4, n3, n2, n1 after n5 sequentially
Then we got the added node data like this:
(id: n4, prev: null, next: n3 )
(id: n3, prev: n4, next: n2 )
(id: n2, prev: n3, next: n1 )
(id: n1, prev: n2, next: null)
The problem comes when we try to replay the first add node datum.
Since its prev node is null, we rely on its next sibling n3. But
n3 was not present at this moment, and in previous code, we fallback
to append n4 to the last of its parent node.
The solution is to defer the append of elements that missing
siblings. But it is also hard to tell which node is the first one
that needs to be appended.
Take a step back and rethink the design of the mutation observer,
we've found there are two implementations make things complicated.
1. We set the id to -1 when we seeing some nodes are not serialized yet.
2. We record both previous sibling and next sibling to determine the
position of the node.
But we can do better!
First, we can put nodes with un-serialized siblings
to a queue, and try to add it again later. Then we can just record the next
sibling as 'the single truth' so we can be sure which node is the last
one of its parent.
This patch has implemented the new observer strategy. Data recorded with
the new observer should no longer have any node with id -1. But for
compatibility consideration, we still keep some replayer code that helps
solve legacy data.
* introduce pako and add general packer interface
* add tests for packer
* use function API instead of class API for better tree shaking support
* refcatoring the rollup bundle config
* added our package
* reverted back to old rrweb snapshot
* Array.from does not capture all elements added in the set, we have to manually iterate through the iterator
* package lock
* checking if nodes are in the parent before we try inserting them
This was a recording taken with rrweb 0.7.27 (3afff63970) and rrweb-snapshot 0.7.21 (a0dc9481b2) so issue may have been fixed in the intervening commits
