We introduced runtime validation of tag names because we used to generate
HTML that was supposed to be inserted into a HTML string which could've
been an XSS attack.
However, these days we use document.createElement in most cases. That
already does its internal validation in the browser which throws. We're now
double validating it. Stack still has a path where innerHTML is used and
we still need it there. However in Fiber we can remove it completely.
In #2756 we ended up using toLowerCase to allow case insensitive HTML tags.
However, this requires extra processing every time we access the tag or
at least we need to process it for mount and store it in an extra field
which wastes memory.
So instead, we can just enforce case sensitivity for HTML since this might
matter for the XML namespaces like SVG anyway.
* Enable additional (failing) portal tests
* Fix portal unmounting
When unmount a portal, we need to unmount *its* children from itself.
This is similar to what we would do for a root if we allowed deleting roots.
* Skip portals when looking for host siblings
A portal is not part of that host tree despite being a child.
* Fix comment typo
* Add a failing test for portal child reconciliation
It is failing because portal bails out of update, seeing null in pendingProps.
It is null because we set pendingProps to nextPortal.children, which is null in this test.
* Fix the bug when switching to a null portal child
If pendingProps is null, we do a bailout in beginWork.
This prevents unmounting of the existing child when the new child is null.
We fix this by changing portal fiber's pendingProps to be the portal object itself instead of its children.
This way, it is never null, and thus doesn't cause a false positive in the bailout condition.
* Add a comment about HostPortal in getHostSibling
* Revert the fix because I don't know why it worked
unmountHostComponents() should have worked despite finding the wrong parent because it should have changed the parent when pushing and popping the portals.
* Don't call commitDeletion recursively
This leads to a "Cannot find host parent" bug because commitDeletion() clears the return field.
When we're inside the loop, we assign node.sibling.return to node.return but by this moment node.return has already been nulled.
As a solution we inline code from commitDeletion() without the nulling.
It still fails tests but for a different reason (unrelated bug).
* Skip portal children in commitNestedUnmounts()
We are currently already visiting them in commitUnmount() portal case since it's recursive.
This condition avoids visting them twice.
* Set node.child.return before going deeper
It doesn't seem to influence existing tests but we have this protection in all other similar places.
It protects against infinite loops.
* Revert "Fix the bug when switching to a null portal child"
This reverts commit ed9747deed.
I'll solve this by using an array in place of null instead.
* Use [] for empty Portal pendingProps
This avoids a false positive bailout with pendingProps == null when portal is empty.
* Test that SVG elements get created with the right namespace
* Pass root to the renderer methods
* Keep track of host instances and containers
* Keep instances instead of fibers on the stack
* Create text instances in begin phase
* Create instance before bailing on offscreen children
Otherwise, the parent gets skipped next time.
We could probably create it later but this seems simpler.
* Tweak magic numbers in incremental tests
I don't understand why they changed but probably related to us moving some work into begin phase?
* Only push newly created nodes on the parent stack
Previously I was pushing nodes on the parent stack regardless of whether they were already in current or not.
As a result, insertions during updates were duplicated, and nodes were added to existing parents before commit phase.
Luckily we have a test that caught that.
* Fix lint
* Fix Flow
I had to wrap HostContext API into a closure so that it's parameterizeable with I and C.
* Use the same destructuring style in scheduler as everywhere else
* Remove branches that don't seem to run anymore
I'm not 100% sure this is right but I can't get tests to fail.
* Be explicit about the difference between type and tag
I was confused by th HACK comment so I learned how DOM and SVG work with casing and tried to write a more descriptive comment.
It also seems like passing fiber.type into finalizeInitialChildren() is a potential problem because DOM code assumes tag is lowercase.
So I added a similar "hack" to finalizeInitialChildren() that is identical to the one we have prepareUpdate() so if we fix them later, we fix both.
* Save and restore host context when pushing and popping portals
* Revert parent context and adding children in the begin phase
We can address this later separately as it is a more hot path.
This doesn't affect correctness of SVG container behavior.
* Add a test for SVG updates
This tests the "jump" reuse code path in particular.
* Record tests
* Read ownerDocument from the root container instance
This way createInstance() depends on the innermost container only for reading the namespace.
* Track namespaces instead of creating instances early
While we might want to create instance in the begin phase, we shouldn't let DOM guide reconciler design.
Instead, we are adding a new concept of "host context". In case of ReactDOMFiber, it's just the current namespace.
We are keeping a stack of host context values, ignoring those that are referentially equal.
The renderer receives the parent context and type, and can return a new context.
* Pop child context before reading own context and clarify API
It wasn't quite clear from the API which context was being returned by the renderer. Changed the API to specifically ask for child context, and thus to pop it before getting the current context.
This fixes the case with <foreignObject> to which I intended to give SVG namespace.
* Give SVG namespace to <svg> itself
* Don't allocate unnecessarily when reconciling portals
We create stacks lazily so that if portal doesn't contain <svg>s, we don't need to allocate.
We also reuse the same object for portal host context state instead of creating a new one every time.
* Add more tests for edge cases
* Fix up math namespace
* Maintain a separate container stack
* Fix rebase mistakes
* Unwind context on errors
* Reset the container state when reusing the object
* Add getChildHostContext() to ReactART
* Record tests
If a ref throws while detaching, it should not prevent
componentWillUnmount from being called.
Additionally, errors thrown by removeChild should not be ignored, even
as the result of unmounting a failed subtree.
This fixes the issue where using the .return pointer isn't guaranteed to
return the current Fiber so we might read the wrong props when we try
to get the current event.
When we perform an update to the event handler we properly update the
immediate Fiber pointer of a child to be the current. However, when we
bubble events we use the return pointer which is not guaranteed to point
to the current Fiber even if we start from the current.
This manifests itself when we bailout in a parent. So I made the tests
use a PureComponent to illustrate this scenario. There is already a failing
case but I'm adding another one too.
This strategy finds the current fiber. It traverses back up to the root if
the two trees are completely separate and determines which one is current.
If the two trees converge anywhere along the way, we assume that is the
current tree. We find the current child by searching the converged child
set.
This could fail if there's any way for both return pointers to point
backwards to the work in progress. I don't think there is but I could be
wrong.
This may also fail on coroutines where we have reparenting situations.
Fixes a bug when updating from a single text child (or
dangerouslySetInnerHTML) to regular children, where the previous
text content never gets deleted.
* Exit early in scheduleUpdate if a node's priority matches
This is a performance optimization and is unobservable. However, it
helps protect against regressions on the following invariants on which
it relies:
- The priority of a fiber is greater than or equal to the priority of
all its descendent fibers.
- If a tree has pending work priority, its root is scheduled.
* New error boundary semantics
- Recovering from an error boundary no longer uses Task priority by
default. The work is scheduled using whatever priority created the
error.
- Error handling is now a side-effect that happens during the
commit phase.
- The default behavior of an error boundary is to render null. Errors
do not propagate except when an boundary fails. Conceptually, this would
be like throwing an error from a catch block.
- A host container is treated like a no-op error boundary. The first
error captured by a host container is thrown at the end of the batch.
Like with normal error boundaries, the entire tree is unmounted.
* Fix broken setState callback test
* Add test for "unwinding" context when an error interrupts rendering
* Switch over primary effect types only
This avoids the need to create an export for every combination of bits.
* Only continue the work loop if the error was successfully captured
* Add more tests for incremental error handling
These tests are currently failing:
✕ catches render error in a boundary during partial deferred mounting
✕ catches render error in a boundary during animation mounting
✕ propagates an error from a noop error boundary during full deferred mounting
✕ propagates an error from a noop error boundary during partial deferred mounting
✕ propagates an error from a noop error boundary during animation mounting
The observed behavior is that unstable_handleError() unexpected gets called twice:
"ErrorBoundary render success",
"BrokenRender",
"ErrorBoundary unstable_handleError",
+ "ErrorBoundary render success",
+ "BrokenRender",
+ "ErrorBoundary unstable_handleError",
"ErrorBoundary render error"
* Verify batched updates get scheduled despite errors
* Add try/catch/finally blocks around commit phase passes
We'll consolidate all these blocks in a future PR that refactors the
commit phase to be separate from the perform work loop.
* NoopBoundary -> RethrowBoundary
* Only throw uncaught error once there is no more work to perform
* Remove outdated comment
It was fixed in #8451.
* Record tests
* Always reset nextUnitOfWork on error
This is important so that the test at the end of performAndHandleErrors() knows it's safe to rethrow.
* Add a passing test for unmounting behavior on crashed tree
* Top-level errors
An error thrown from a host container should be "captured" by the host
container itself
* Remove outdated comment
* Separate Rethrow and Noop scenarios in boundary tests
* Move try block outside the commit loops
* Make bad element type message same as in Stack
This makes Fiber emit the same message as Stack (aside from the missing owner information).
* Add a separate test verifying error includes owner name
Fiber currently doesn't pass it. This is just to keep track of it as a todo.
* Add iterable cases to MultiChildReconcile test
Stack currently supports rendering iterables, but Fiber does not.
Previously we didn't have any public API tests for iterables. We have tests for traverseAllChildren() which is shared between React.Children and Stack. However Fiber doesn't currently use it, and likely won't. So this commit is a first step towards actually testing iterable support via public API. The next step will be to port traverseAllChildren() tests to test React.Children API instead.
* Implement iterable reconciliation in Fiber
This uses the same exact algorithm as array reconciliation but uses iterator to step through.
This gets reconcile tests to pass again but introduces a regression in ReactMultiChildText case which uses Maps as children. It passed before because Maps were ignored, but now it's failing because this actually runs the Map code path in Fiber. We can throw early in this case when we want to follow up on this.
* Rewrite traverseAllChildren() tests against React.Children API
This function was used in React.Children and Stack.
The corresponding reconciliation functionality is being tested by ReactMultiChild tests.
So we can move these tests to ReactChildren and test its public API.
* Use a closure to bind gaurded callback
This way the fake event isn't being implicitly passed into the event handler
* Add tests for ReactErrorUtils
Add fiber test report
Linting fixes
We used to terminate the search on host nodes, and then use the nested unmount algorithm.
However this means we didn't unmount portals inside the host nodes.
We will probably need to restructure this somehow but for now I just added a recursive call to unblock myself.
