Previously, DevTools filtered empty commits on the backend, while profiling, through the use of a bailout heuristic that React currently happens to use. This approach was brittle and may have exacerbated the long-standing Profiler bug #16446.
This PR removes that heuristic and adds as a post-processing filtering pass instead. This removes the coupling between DevTools and a React internal implementation detail that may change.
I believe DevTools has two choices of criteria for this filtering:
* Filter commits that have no actual duration metadata.
* Filter commits that have no recorded operations (no mutations to the tree, no changed tree base durations).
I chose the first option, filtering by commits that have no reported metadata. It will miss an edge case, e.g. , but we would have nothing meaningful to show in the Profiler for those cases anyway. (This particular edge case is why one of the snapshots changed with this commit.)
The second option, filtering by recorded operations, could potentially miss a more important edge case: where a component *did* render, but its didn't change. (In that event, there would be no operations to send.)
stateNode is not one of the fields that gets copied over by createWorkInProgress.
This is bad for persistent mode since it's not the same instance.
In HostComponent we happened to always end up transferring the current stateNode when we bail.
However, we didn't do this for HostText.
DevTools previously called in several places with user-defined values. This could lead to runtime errors if those values had an overriden attribute. This commit replaces those callse with instead.
New test cases have been added.
The Profiler stores:
1. A snapshot of the React tree when profiling started
2. The operations array for each commit
3. Profiling metadata (e.g. durations, what changed, etc) for each commit
It uses this information (snapshot + operations diff) to reconstruct the state of the application for a given commit as it's viewed in the Profiler UI. Because of this, it's very important that the operations and metadata arrays align. If they don't align, the profiler will be unable to correctly reconstruct the tree, and it will likely throw errors (like 'Could not find node…')
#16446 tracks a long-standing bug where these two arrays get misaligned. I am still not entirely sure what causes this bug, but with PR #17253, I exacerbated things by introducing another potential way for it to happen. This PR addresses the regression at least (and adds test coverage for it).
I will follow up this afternoon on the original #16446 issue. I think I may have a lead on what's happening at least, if not exactly an idea of how to reproduce it.
I used to disable the <- and -> buttons when you reached the beginning or end of the profiler data. This can be kind of annoying though when you just want to get to the last commit, and I don't think there's a good reason to enforce it anyway, so I backed that change out. The buttons now wrap around at the beginning or end of the list.
The param should probably be a generic type, but I'm not sure how to satisfy Flow with the current top-level Map. At least this adds basic coverage (which was missing before, oops).
Previously, when props/state contained a regexp, it was shown as an
empty object. This commit adds regexps as values in need of special
rehydration (like Symbols or TypedArrays), and display them as a user
might expect.
Co-authored-by: Zirak <zirakertan@gmail.com>
Moves the unit testing library for events into the `packages` directory so it can more easily be used in tests for other react packages, and mirrored internally to help with testing of event hooks we prototype in www.
Introduces a state machine around pointer events to produce more accurate mock
touch events. This allows multi-touch unit tests to be written entirely in
terms of mock pointer interactions, while producing the expected
'changedTouches', 'targetTouches', and 'touches' fields for mock touch events.
* Updated DevTools local development instructions to mention experimental build step
* Added a command to download latest experimental release (for DevTools)
* Updated build instructions for clarity
* Added build-for-devtools package alias
* Added rudimentary context menu hook and menu UI
* Added backend support for copying a value at a specific path for the inspected element
* Added backend support for storing a value (at a specified path) as a global variable
* Added special casing to enable copying undefined/unserializable values to the clipboard
* Added copy and store-as-global context menu options to selected element props panel
* Store global variables separately, with auto-incremented name (like browsers do)
* Added tests for new copy and store-as-global backend functions
* Fixed some ownerDocument/contentWindow edge cases
* Refactored context menu to support dynamic options
Used this mechanism to add a conditional menu option for inspecting the current value (if it's a function)
* Renamed "safeSerialize" to "serializeToString" and added inline comment
* Add feature flags
* Add Chunk type and constructor
* Wire up Chunk support in the reconciler
* Update reconciler to reconcile Chunks against the render method
This allows the query and args to be updated.
* Drop the ref. Chunks cannot have refs anyway.
* Add Chunk checks in more missing cases
* Rename secondArg
* Add test and fix lazy chunks
Not really a supported use case but for consistency I guess.
* Fix fragment test
* Favor fallthrough switch instead of case statements for work tags
Currently we're inconsistently handling tags that are only relevant
for certain flags. We should throw if the tag is not part of the built
feature flags. This should also mean that the case statements can be
eliminated.
We can achieve this effect by putting the invariant outside of the switch
and always early return in the switch. We already do this in beginWork.
This PR makes this consistent in other places.
* Fail if fundamental/scope tags are discovered without the flag on
* fix(dev-tools): fix show correct displayName with forwardRef in Dev Tools
allow set `displayName` after `React.forwardRef()`,
makesure Dev Tools show displayName as same as `getWrappedName` in `shared/getComponentName.js`
* Removed a little unnecessary/redundant code.
* Fixed lint error (removed unused var)
1. Enable nested values to be expanded/collapsed by clicking on values as well as keys.
2. Enable keys and values to be selectable (for copy-pasting purposes)