Summary:
- add type to represent the returned component tree
```
expected data:
{
[nodeID1]: [subtree1],
[nodeID2]: [subtree2],
...
}
example:
{
id1: {
id2: {
id3: {
id4: {},
id5: {
id6: {}
}
}
}
}
}
```
- add functions to deal with a tree
- `_getElementLeaves` for finding ids that don't have any child given the tree structure
- `_getPathForNode` for finding path (similar to previous path parameter) for given id
- This diff still retain functionality in case of selector appear to touch only one element.
Reviewed By: mweststrate
Differential Revision: D21040427
fbshipit-source-id: e6704535a437ad47d9664cc16896b9f24c9d6736
a7163bf06d