Commit Graph

82 Commits

Author SHA1 Message Date
Andrew Clark a724a3b578
[RFC] Codemod invariant -> throw new Error (#22435)
* Hoist error codes import to module scope

When this code was written, the error codes map (`codes.json`) was
created on-the-fly, so we had to lazily require from inside the visitor.

Because `codes.json` is now checked into source, we can import it a
single time in module scope.

* Minify error constructors in production

We use a script to minify our error messages in production. Each message
is assigned an error code, defined in `scripts/error-codes/codes.json`.
Then our build script replaces the messages with a link to our
error decoder page, e.g. https://reactjs.org/docs/error-decoder.html/?invariant=92

This enables us to write helpful error messages without increasing the
bundle size.

Right now, the script only works for `invariant` calls. It does not work
if you throw an Error object. This is an old Facebookism that we don't
really need, other than the fact that our error minification script
relies on it.

So, I've updated the script to minify error constructors, too:

Input:
  Error(`A ${adj} message that contains ${noun}`);
Output:
  Error(formatProdErrorMessage(ERR_CODE, adj, noun));

It only works for constructors that are literally named Error, though we
could add support for other names, too.

As a next step, I will add a lint rule to enforce that errors written
this way must have a corresponding error code.

* Minify "no fallback UI specified" error in prod

This error message wasn't being minified because it doesn't use
invariant. The reason it didn't use invariant is because this particular
error is created without begin thrown — it doesn't need to be thrown
because it's located inside the error handling part of the runtime.

Now that the error minification script supports Error constructors, we
can minify it by assigning it a production error code in
`scripts/error-codes/codes.json`.

To support the use of Error constructors more generally, I will add a
lint rule that enforces each message has a corresponding error code.

* Lint rule to detect unminified errors

Adds a lint rule that detects when an Error constructor is used without
a corresponding production error code.

We already have this for `invariant`, but not for regular errors, i.e.
`throw new Error(msg)`. There's also nothing that enforces the use of
`invariant` besides convention.

There are some packages where we don't care to minify errors. These are
packages that run in environments where bundle size is not a concern,
like react-pg. I added an override in the ESLint config to ignore these.

* Temporarily add invariant codemod script

I'm adding this codemod to the repo temporarily, but I'll revert it
in the same PR. That way we don't have to check it in but it's still
accessible (via the PR) if we need it later.

* [Automated] Codemod invariant -> Error

This commit contains only automated changes:

npx jscodeshift -t scripts/codemod-invariant.js packages --ignore-pattern="node_modules/**/*"
yarn linc --fix
yarn prettier

I will do any manual touch ups in separate commits so they're easier
to review.

* Remove temporary codemod script

This reverts the codemod script and ESLint config I added temporarily
in order to perform the invariant codemod.

* Manual touch ups

A few manual changes I made after the codemod ran.

* Enable error code transform per package

Currently we're not consistent about which packages should have their
errors minified in production and which ones should.

This adds a field to the bundle configuration to control whether to
apply the transform. We should decide what the criteria is going
forward. I think it's probably a good idea to minify any package that
gets sent over the network. So yes to modules that run in the browser,
and no to modules that run on the server and during development only.
2021-09-30 12:01:28 -07:00
Justin Grant c88fb49d37
Improve DEV errors if string coercion throws (Temporal.*, Symbol, etc.) (#22064)
* Revise ESLint rules for string coercion

Currently, react uses `'' + value` to coerce mixed values to strings.
This code will throw for Temporal objects or symbols.

To make string-coercion safer and to improve user-facing error messages,
This commit adds a new ESLint rule called `safe-string-coercion`.

This rule has two modes: a production mode and a non-production mode.
* If the `isProductionUserAppCode` option is true, then `'' + value`
  coercions are allowed (because they're faster, although they may
  throw) and `String(value)` coercions are disallowed. Exception:
  when building error messages or running DEV-only code in prod
  files, `String()` should be used because it won't throw.
* If the `isProductionUserAppCode` option is false, then `'' + value`
  coercions are disallowed (because they may throw, and in non-prod
  code it's not worth the risk) and `String(value)` are allowed.

Production mode is used for all files which will be bundled with
developers' userland apps. Non-prod mode is used for all other React
code: tests, DEV blocks, devtools extension, etc.

In production mode, in addiiton to flagging `String(value)` calls,
the rule will also flag `'' + value` or `value + ''` coercions that may
throw. The rule is smart enough to silence itself in the following
"will never throw" cases:
* When the coercion is wrapped in a `typeof` test that restricts to safe
  (non-symbol, non-object) types. Example:
    if (typeof value === 'string' || typeof value === 'number') {
      thisWontReport('' + value);
    }
* When what's being coerced is a unary function result, because unary
   functions never return an object or a symbol.
* When the coerced value is a commonly-used numeric identifier:
  `i`, `idx`, or `lineNumber`.
* When the statement immeidately before the coercion is a DEV-only
  call to a function from shared/CheckStringCoercion.js. This call is a
  no-op in production, but in DEV it will show a console error
  explaining the problem, then will throw right after a long explanatory
  code comment so that debugger users will have an idea what's going on.
  The check function call must be in the following format:
    if (__DEV__) {
      checkXxxxxStringCoercion(value);
    };

Manually disabling the rule is usually not necessary because almost all
prod use of the `'' + value` pattern falls into one of the categories
above. But in the rare cases where the rule isn't smart enough to detect
safe usage (e.g. when a coercion is inside a nested ternary operator),
manually disabling the rule will be needed.

The rule should also be manually disabled in prod error handling code
where `String(value)` should be used for coercions, because it'd be
bad to throw while building an error message or stack trace!

The prod and non-prod modes have differentiated error messages to
explain how to do a proper coercion in that mode.

If a production check call is needed but is missing or incorrect
(e.g. not in a DEV block or not immediately before the coercion), then
a context-sensitive error message will be reported so that developers
can figure out what's wrong and how to fix the problem.

Because string coercions are now handled by the `safe-string-coercion`
rule, the `no-primitive-constructor` rule no longer flags `String()`
usage. It still flags `new String(value)` because that usage is almost
always a bug.

* Add DEV-only string coercion check functions

This commit adds DEV-only functions to check whether coercing
values to strings using the `'' + value` pattern will throw. If it will
throw, these functions will:
1. Display a console error with a friendly error message describing
   the problem and the developer can fix it.
2. Perform the coercion, which will throw. Right before the line where
   the throwing happens, there's a long code comment that will help
   debugger users (or others looking at the exception call stack) figure
   out what happened and how to fix the problem.

One of these check functions should be called before all string coercion
of user-provided values, except when the the coercion is guaranteed not
to throw, e.g.
* if inside a typeof check like `if (typeof value === 'string')`
* if coercing the result of a unary function like `+value` or `value++`
* if coercing a variable named in a whitelist of numeric identifiers:
  `i`, `idx`, or `lineNumber`.

The new `safe-string-coercion` internal ESLint rule enforces that
these check functions are called when they are required.

Only use these check functions in production code that will be bundled
with user apps.  For non-prod code (and for production error-handling
code), use `String(value)` instead which may be a little slower but will
never throw.

* Add failing tests for string coercion

Added failing tests to verify:
* That input, select, and textarea elements with value and defaultValue
  set to Temporal-like objects which will throw when coerced to string
  using the `'' + value` pattern.
* That text elements will throw for Temporal-like objects
* That dangerouslySetInnerHTML will *not* throw for Temporal-like
  objects because this value is not cast to a string before passing to
  the DOM.
* That keys that are Temporal-like objects will throw

All tests above validate the friendly error messages thrown.

* Use `String(value)` for coercion in non-prod files

This commit switches non-production code from `'' + value` (which
throws for Temporal objects and symbols) to instead use `String(value)`
which won't throw for these or other future plus-phobic types.

"Non-produciton code" includes anything not bundled into user apps:
* Tests and test utilities. Note that I didn't change legacy React
  test fixtures because I assumed it was good for those files to
  act just like old React, including coercion behavior.
* Build scripts
* Dev tools package - In addition to switching to `String`, I also
  removed special-case code for coercing symbols which is now
  unnecessary.

* Add DEV-only string coercion checks to prod files

This commit adds DEV-only function calls to to check if string coercion
using `'' + value` will throw, which it will if the value is a Temporal
object or a symbol because those types can't be added with `+`.

If it will throw, then in DEV these checks will show a console error
to help the user undertsand what went wrong and how to fix the
problem. After emitting the console error, the check functions will
retry the coercion which will throw with a call stack that's easy (or
at least easier!) to troubleshoot because the exception happens right
after a long comment explaining the issue. So whether the user is in
a debugger, looking at the browser console, or viewing the in-browser
DEV call stack, it should be easy to understand and fix the problem.

In most cases, the safe-string-coercion ESLint rule is smart enough to
detect when a coercion is safe. But in rare cases (e.g. when a coercion
is inside a ternary) this rule will have to be manually disabled.

This commit also switches error-handling code to use `String(value)`
for coercion, because it's bad to crash when you're trying to build
an error message or a call stack!  Because `String()` is usually
disallowed by the `safe-string-coercion` ESLint rule in production
code, the rule must be disabled when `String()` is used.
2021-09-27 10:05:07 -07:00
Ricky 310187264d
Clean up flushSync flow types (#21887) 2021-07-16 10:37:57 -04:00
Andrew Clark a4ecd85e86
act: Batch updates, even in legacy roots (#21797)
In legacy roots, if an update originates outside of `batchedUpdates`,
check if it's inside an `act` scope; if so, treat it as if it were
batched. This is only necessary in legacy roots because in concurrent
roots, updates are batched by default.

With this change, the Test Utils and Test Renderer versions of `act` are
nothing more than aliases of the isomorphic API (still not exposed, but
will likely be the recommended API that replaces the others).
2021-07-12 17:15:20 -07:00
Andrew Clark cae635054e
`act`: Resolve to return value of scope function (#21759)
When migrating some internal tests I found it annoying that I couldn't
return anything from the `act` scope. You would have to declare the
variable on the outside then assign to it. But this doesn't play well
with type systems — when you use the variable, you have to check
the type.

Before:

```js
let renderer;
act(() => {
  renderer = ReactTestRenderer.create(<App />);
})

// Type system can't tell that renderer is never undefined
renderer?.root.findByType(Component);
```

After:

```js
const renderer = await act(() => {
  return ReactTestRenderer.create(<App />);
})
renderer.root.findByType(Component);
```
2021-06-26 11:51:23 -07:00
Andrew Clark d7dce572c7
Remove internal `act` builds from public modules (#21721)
* Move internal version of act to shared module

No reason to have three different copies of this anymore.

I've left the the renderer-specific `act` entry points because legacy
mode tests need to also be wrapped in `batchedUpdates`. Next, I'll update
the tests to use `batchedUpdates` manually when needed.

* Migrates tests to use internal module directly

Instead of the `unstable_concurrentAct` exports. Now we can drop those
from the public builds.

I put it in the jest-react package since that's where we put our other
testing utilities (like `toFlushAndYield`). Not so much so it can be
consumed publicly (nobody uses that package except us), but so it works
with our build tests.

* Remove unused internal fields

These were used by the old act implementation. No longer needed.
2021-06-22 14:29:35 -07:00
Andrew Clark 06f7b4f43a
`act` should work without mock Scheduler (#21714)
Currently, in a React 18 root, `act` only works if you mock the
Scheduler package. This was because we didn't want to add additional
checks at runtime.

But now that the `act` testing API is dev-only, we can simplify its
implementation.

Now when an update is wrapped with `act`, React will bypass Scheduler
entirely and push its tasks onto a special internal queue. Then, when
the outermost `act` scope exists, we'll flush that queue.

I also removed the "wrong act" warning, because the plan is to move
`act` to an isomorphic entry point, simlar to `startTransition`. That's
not directly related to this PR, but I didn't want to bother
re-implementing that warning only to immediately remove it.

I'll add the isomorphic API in a follow up.

Note that the internal version of `act` that we use in our own tests
still depends on mocking the Scheduler package, because it needs to work
in production. I'm planning to move that implementation to a shared
(internal) module, too.
2021-06-22 14:25:07 -07:00
Ricky e9a4a44aae
Add back root override for strict mode (#21428)
* Add back root override for strict mode

* Switch flag to boolean

* Fix flow
2021-05-04 15:42:48 -04:00
Brian Vaughn 15fb8c3045
createRoot API is no longer strict by default (#21417) 2021-05-03 16:57:03 -04:00
Ricky 9e9dac6505
Add unstable_concurrentUpdatesByDefault (#21227) 2021-04-28 16:09:30 -04:00
Sebastian Markbåge 172e89b4bf
Reland Remove redundant initial of isArray (#21188)
* Remove redundant initial of isArray (#21163)

* Reapply prettier

* Type the isArray function with refinement support

This ensures that an argument gets refined just like it does if isArray is
used directly.

I'm not sure how to express with just a direct reference so I added a
function wrapper and confirmed that this does get inlined properly by
closure compiler.

* A few more

* Rename unit test to internal

This is not testing a bundle.

Co-authored-by: Behnam Mohammadi <itten@live.com>
2021-04-07 07:57:43 -07:00
Brian Vaughn 7df65725ba
Split getComponentName into getComponentNameFromFiber and getComponentNameFromType (#20940)
Split getComponentName into getComponentNameFromFiber and getComponentNameFromType
2021-03-05 16:02:02 -05:00
Andrew Clark de0ee76dbd
Add unstable_strictModeLevel to test renderer (#20914)
Matches what we do for React DOM
2021-03-02 10:41:57 -08:00
Brian Vaughn 9209c30ff9
Add StrictMode level prop and createRoot unstable_strictModeLevel option (#20849)
* The exported '<React.StrictMode>' tag remains the same and opts legacy subtrees into strict mode level one ('mode == StrictModeL1'). This mode enables DEV-only double rendering, double component lifecycles, string ref warnings, legacy context warnings, etc. The primary purpose of this mode is to help detected render phase side effects. No new behavior. Roots created with experimental 'createRoot' and 'createBlockingRoot' APIs will also (for now) continue to default to strict mode level 1.

In a subsequent commit I will add support for a 'level' attribute on the '<React.StrictMode>' tag (as well as a new option supported by ). This will be the way to opt into strict mode level 2 ('mode == StrictModeL2'). This mode will enable DEV-only double invoking of effects on initial mount. This will simulate future Offscreen API semantics for trees being mounted, then hidden, and then shown again. The primary purpose of this mode is to enable applications to prepare for compatibility with the new Offscreen API (more information to follow shortly).

For now, this commit changes no public facing behavior. The only mechanism for opting into strict mode level 2 is the pre-existing 'enableDoubleInvokingEffects' feature flag (only enabled within Facebook for now).

* Renamed strict mode constants

StrictModeL1 -> StrictLegacyMode and StrictModeL2 -> StrictEffectsMode

* Renamed tests

* Split strict effects mode into two flags

One flag ('enableStrictEffects') enables strict mode level 2. It is similar to 'debugRenderPhaseSideEffectsForStrictMode' which enables srtict mode level 1.

The second flag ('createRootStrictEffectsByDefault') controls the default strict mode level for 'createRoot' trees. For now, all 'createRoot' trees remain level 1 by default. We will experiment with level 2 within Facebook.

This is a prerequisite for adding a configurable option to 'createRoot' that enables choosing a different StrictMode level than the default.

* Add StrictMode 'unstable_level' prop and createRoot 'unstable_strictModeLevel' option

New StrictMode 'unstable_level' prop allows specifying which level of strict mode to use. If no level attribute is specified, StrictLegacyMode will be used to maintain backwards compatibility. Otherwise the following is true:
* Level 0 does nothing
* Level 1 selects StrictLegacyMode
* Level 2 selects StrictEffectsMode (which includes StrictLegacyMode)

Levels can be increased with nesting (0 -> 1 -> 2) but not decreased.

This commit also adds a new 'unstable_strictModeLevel' option to the createRoot and createBatchedRoot APIs. This option can be used to override default behavior to increase or decrease the StrictMode level of the root.

A subsequent commit will add additional DEV warnings:
* If a nested StrictMode tag attempts to explicitly decrease the level
* If a level attribute changes in an update
2021-02-24 16:14:14 -05:00
Sebastian Markbåge 56e9feead0
Remove Blocks (#20138)
* Remove Blocks

* Remove Flight Server Runtime

There's no need for this now that the JSResource is part of the bundler
protocol. Might need something for Webpack plugin specifically later.

* Devtools
2020-10-30 23:03:45 -07:00
Andrew Clark e7b255341b
Internal `act`: Flush timers at end of scope (#19788)
If there are any suspended fallbacks at the end of the `act` scope,
force them to display by running the pending timers (i.e. `setTimeout`).

The public implementation of `act` achieves the same behavior with an
extra check in the work loop (`shouldForceFlushFallbacks`). Since our
internal `act` needs to work in both development and production, without
additional runtime checks, we instead rely on Jest's mock timers.

This doesn't not affect refresh transitions, which are meant to delay
indefinitely, because in that case we exit the work loop without
posting a timer.
2020-09-08 21:55:23 -07:00
Andrew Clark d17086c7c8
Decouple public, internal act implementation (#19745)
In the next major release, we intend to drop support for using the `act`
testing helper in production. (It already fires a warning.) The
rationale is that, in order for `act` to work, you must either mock the
testing environment or add extra logic at runtime. Mocking the testing
environment isn't ideal because it requires extra set up for the user.
Extra logic at runtime is fine only in development mode — we don't want
to slow down the production builds.

Since most people only run their tests in development mode, dropping
support for production should be fine; if there's demand, we can add it
back later using a special testing build that is identical to the
production build except for the additional testing logic.

One blocker for removing production support is that we currently use
`act` to test React itself. We must test React in both development and
production modes.

So, the solution is to fork `act` into separate public and
internal implementations:

- *public implementation of `act`* – exposed to users, only works in
  development mode, uses special runtime logic, does not support partial
  rendering
- *internal implementation of `act`* – private, works in both
  development and productionm modes, only used by the React Core test
  suite, uses no special runtime logic, supports partial rendering (i.e.
  `toFlushAndYieldThrough`)

The internal implementation should mostly match the public
implementation's behavior, but since it's a private API, it doesn't have
to match exactly. It works by mocking the test environment: it uses a
mock build of Scheduler to flush rendering tasks, and Jest's mock timers
to flush Suspense placeholders.

---

In this first commit, I've added the internal forks of `act` and
migrated our tests to use them. The public `act` implementation is
unaffected for now; I will leave refactoring/clean-up for a later step.
2020-09-08 08:11:45 -07:00
Andrew Clark 376d5c1b5a Split cross-package types from implementation
Some of our internal reconciler types have leaked into other packages.
Usually, these types are treated as opaque; we don't read and write
to its fields. This is good.

However, the type is often passed back to a reconciler method. For
example, React DOM creates a FiberRoot with `createContainer`, then
passes that root to `updateContainer`. It doesn't do anything with the
root except pass it through, but because `updateContainer` expects a
full FiberRoot, React DOM is still coupled to all its fields.

I don't know if there's an idiomatic way to handle this in Flow. Opaque
types are simlar, but those only work within a single file. AFAIK,
there's no way to use a package as the boundary for opaqueness.

The immediate problem this presents is that the reconciler refactor will
involve changes to our internal data structures. I don't want to have to
fork every single package that happens to pass through a Fiber or
FiberRoot, or access any one of its fields. So my current plan is to
share the same Flow type across both forks. The shared type will be a
superset of each implementation's type, e.g. Fiber will have both an
`expirationTime` field and a `lanes` field. The implementations will
diverge, but not the types.

To do this, I lifted the type definitions into a separate module.
2020-04-08 23:49:23 -07:00
Andrew Clark d686f3f16a Add `.old` prefix to reconciler modules 2020-04-08 23:49:19 -07:00
Sebastian Markbåge c5d2fc7127
Move some files out of /shared and rename to upper case (#18363)
* Rename lower case isomorphic default exports modules to upper case named exports

We're somewhat inconsistent here between e.g. ReactLazy and memo.

Let's pick one.

This also moves the responder, fundamental, scope creators from shared
since they're isomorphic and same as the other creators.

* Move some files that are specific to the react-reconciler from shared

Individual renderers are allowed to deep require into the reconciler.

* Move files specific to react-dom from shared

react-interactions is right now dom specific (it wasn't before) so we can
type check it together with other dom stuff. Avoids the need for
a shared ReactDOMTypes to be checked by RN for example.

* Move ReactWorkTags to the reconciler

* Move createPortal to export from reconciler

Otherwise Noop can't access it since it's not allowed deep requires.
2020-03-21 15:22:01 -07:00
Sebastian Markbåge 7a1691cdff
Refactor Host Config Infra (getting rid of .inline*.js) (#18240)
* Require deep for reconcilers

* Delete inline* files

* Delete react-reconciler/persistent

This no longer makes any sense because it react-reconciler takes
supportsMutation or supportsPersistence as options. It's no longer based
on feature flags.

* Fix jest mocking

* Fix Flow strategy

We now explicitly list which paths we want to be checked by a renderer.
For every other renderer config we ignore those paths.

Nothing is "any" typed. So if some transitive dependency isn't reachable
it won't be accidentally "any" that leaks.
2020-03-06 16:20:42 -08:00
Henry Q. Dineen 053347e6bc
react-test-renderer: improve findByType() error message (#17439)
* improve findByType error message

* fix flow typing

* Adding a test for the "Unknown" branch when `getComponentName()` returns a falsy value. The error message in this case not the most descriptive but seems consistent with the `getComponentName(type) || 'Unknown'` pattern seen in multiple places in this code base.
2020-02-28 17:55:33 +00:00
Sebastian Markbåge f9c0a45441
Convert the rest of react-dom and react-test-renderer to Named Exports (#18145)
Nothing interesting here except that ReactShallowRenderer currently exports
a class with a static method instead of an object.

I think the public API is probably just meant to be createRenderer but
currently the whole class is exposed. So this means that we have to keep
it as default export. We could potentially also expose a named export for
createRenderer but that's going to cause compatibility issues.

So I'm just going to make that export default.

Unfortunately Rollup and Babel (which powers Jest) disagree on how to
import this. So to make it work I had to move the jest tests to imports.

This doesn't work with module resetting. Some tests weren't doing that
anyway and the rest is just testing ReactShallowRenderer so meh.
2020-02-26 18:04:32 -08:00
Sebastian Markbåge 65bbda7f16
Rename Chunks API to Blocks (#18086)
Sounds like this is the name we're going with. This also helps us
distinguish it from other "chunking" implementation details.
2020-02-20 23:56:40 -08:00
Sunil Pai 3e9251d605
make testing builds for React/ReactDOM (#17915)
This PR introduces adds `react/testing` and `react-dom/testing`.
- changes infra to generate these builds
- exports act on ReactDOM in these testing builds
- uses the new test builds in fixtures/dom

In the next PR -

- I'll use the new builds for all our own tests
- I'll replace usages of TestUtils.act with ReactDOM.act.
2020-02-03 23:31:31 +00:00
Dan Abramov e706721490
Update Flow to 0.84 (#17805)
* Update Flow to 0.84

* Fix violations

* Use inexact object syntax in files from fbsource

* Fix warning extraction to use a modern parser

* Codemod inexact objects to new syntax

* Tighten types that can be exact

* Revert unintentional formatting changes from codemod
2020-01-09 14:50:44 +00:00
Sebastian Markbåge 7dc9745427
[Flight] Chunks API (#17398)
* 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
2019-12-18 18:25:43 +00:00
Dominic Gannaway 46f912fd57
[react-core] Add more support for experimental React Scope API (#16621) 2019-08-30 18:27:14 +01:00
Sebastian Markbåge c80678c760
Add "hydrationOptions" behind the enableSuspenseCallback flag (#16434)
This gets invoked when a boundary is either hydrated or if it is deleted
because it updated or got deleted before it mounted.
2019-08-19 13:26:39 -07:00
Andrew Clark 862f499fac
Add Batched Mode (#15502)
* Add Batched Mode

React has an unfortunate quirk where updates are sometimes synchronous
-- where React starts rendering immediately within the call stack of
`setState` — and sometimes batched, where updates are flushed at the
end of the current event. Any update that originates within the call
stack of the React event system is batched. This encompasses most
updates, since most updates originate from an event handler like
`onClick` or `onChange`. It also includes updates triggered by lifecycle
methods or effects. But there are also updates that originate outside
React's event system, like timer events, network events, and microtasks
(promise resolution handlers). These are not batched, which results in
both worse performance (multiple render passes instead of single one)
and confusing semantics.

Ideally all updates would be batched by default. Unfortunately, it's
easy for components to accidentally rely on this behavior, so changing
it could break existing apps in subtle ways.

One way to move to a batched-by-default model is to opt into Concurrent
Mode (still experimental). But Concurrent Mode introduces additional
semantic changes that apps may not be ready to adopt.

This commit introduces an additional mode called Batched Mode. Batched
Mode enables a batched-by-default model that defers all updates to the
next React event. Once it begins rendering, React will not yield to
the browser until the entire render is finished.

Batched Mode is superset of Strict Mode. It fires all the same warnings.
It also drops the forked Suspense behavior used by Legacy Mode, in favor
of the proper semantics used by Concurrent Mode.

I have not added any public APIs that expose the new mode yet. I'll do
that in subsequent commits.

* Suspense in Batched Mode

Should have same semantics as Concurrent Mode.

* Use RootTag field to configure type of root

There are three types of roots: Legacy, Batched, and Concurrent.

* flushSync should not flush batched work

Treat Sync and Batched expiration times separately. Only Sync updates
are pushed to our internal queue of synchronous callbacks.

Renamed `flushImmediateQueue` to `flushSyncCallbackQueue` for clarity.
2019-05-13 14:30:39 -07:00
Sunil Pai aed0e1c30c
await act(async () => ...) (#14853)
This took a while, but I'm happy I went through it. Some key moments - recursively flushing effects, flushing microtasks on each async turn, and my team's uncompromising philosophy on code reuse. Really happy with this. I still want to expand test coverage, and I have some more small related todos, but this is good to land. On to the next one. 

Soundtrack to landing this - https://open.spotify.com/track/0MF8I8OUo8kytiOo8aSHYq?si=gSWqUheKQbiQDXzptCXHTg

* hacked up act(async () => {...})

* move stuff around

* merge changes

* abstract .act warnings and stuff. all renderers. pass all tests.

* move testutils.act back into testutils

* move into scheduler, rename some bits

* smaller bundle

* a comment for why we don't do typeof === 'function'

* fix test

* pass tests - fire, prod

* lose actContainerElement

* tighter

* write a test for TestRenderer

it's an odd one, because not only does sync act not flush effects correctly, but the async one does (wut). verified it's fine with the dom version.

* lint

* rewrote to move flushing logic closer to the renderer

the scheduler's `flushPassiveEffects` didn't work as expected for the test renderer, so I decided to go back to the hack (rendering a dumb container) This also makes reactdom not as heavy (by a few bytes, but still).

* move it around so the delta isn't too bad

* cleanups

fix promise chaining
propagate errors correctly
test for thenable the 'right' way
more tests!
tidier!
ponies!

* Stray comment

* recursively flush effects

* fixed tests

* lint, move noop.act into react-reconciler

* microtasks when checking if called, s/called/calledLog, cleanup

* pass fb lint

we could have globally changed our eslint config to assume Promise is available, but that means we expect a promise polyfill on the page, and we don't yet. this code is triggered only in jest anyway, and we're fairly certain Promise will be available there. hence, the once-off disable for the check

* shorter timers, fix a test, test for Promise

* use global.Promise for existence check

* flush microtasks

* a version that works in browsers (that support postMessage)

I also added a sanity fixture inside fixtures/dom/ mostly for me.

* hoist flushEffectsAndMicroTasks

* pull out tick logic from ReactFiberScheduler

* fix await act (...sync) hanging

- fix a hang when awaiting sync logic
- a better async/await test for test renderer

* feedback changes

- use node's setImmediate if available
- a warning if MessageChannel isn't available
- rename some functions

* pass lint/flow checks (without requiring a Promise polyfill/exclusion)

* prettier

the prettiest, even.

* use globalPromise for the missed await warning

* __DEV__ check for didWarnAboutMessageChannel

* thenables and callbacks instead of promises, pass flow/lint

* tinier. better.

- pulled most bits out of FiberScheduler
- actedUpdates uses callbacks now

* pass build validation

* augh prettier

* golfing 7 more chars

* Test that effects are not flushed without also flushing microtasks

* export doesHavePendingPassiveEffects, nits

* createAct()

* dead code

* missed in merge?

* lose the preflushing bits

* ugh prettier

* removed `actedUpdates()`, created shared/actingUpdatesScopeDepth

* rearrange imports so builds work, remove the hack versions of flushPassiveEffects

* represent actingUpdatesScopeDepth as a tuple [number]

* use a shared flag on React.__SECRET...

* remove createAct, setup act for all relevant renderers

* review feedback

shared/enqueueTask

import ReactSharedInternals from 'shared/ReactSharedInternals';

simpler act() internals

ReactSharedInternals.ReactShouldWarnActingUpdates

* move act() implementation into createReactNoop

* warnIfNotCurrentlyActingUpdatesInDev condition check order
2019-04-02 22:33:31 +01:00
Andrew Clark ccb2a8a44e
Replace test renderer's fake Scheduler implementation with mock build (#14970)
* Replace test renderer's fake Scheduler implementation with mock build

The test renderer has its own mock implementation of the Scheduler
interface, with the ability to partially render work in tests. Now that
this functionality has been lifted into a proper mock Scheduler build,
we can use that instead.

* Fix Profiler tests in prod
2019-02-28 10:50:38 -08:00
Sunil Pai d1326f466a
[TestUtils.act] fix return result checking (#14758)
* fix .act return value testing when result === null

* nit
2019-02-05 17:34:21 +00:00
Sunil Pai 267ed98146
expose `TestUtils.act()` for batching actions in tests (#14744)
* expose unstable_interact for batching actions in tests

* move to TestUtils

* move it all into testutils

* s/interact/act

* warn when calling hook-like setState outside batching mode

* pass tests

* merge-temp

* move jsdom test to callsite

* mark failing tests

* pass most tests (except one)

* augh IE

* pass fuzz tests

* better warning, expose the right batchedUpdates on TestRenderer for www

* move it into hooks, test for dom

* expose a flag on the host config, move stuff around

* rename, pass flow

* pass flow... again

* tweak .act() type

* enable for all jest environments/renderers; pass (most) tests.

* pass all tests

* expose just the warning from the scheduler

* don't return values

* a bunch of changes.

can't return values from .act
don't try to await .act calls
pass tests

* fixes and nits

* "fire events that udpates state"

* nit

* 🙄

* my bad

* hi andrew

(prettier fix)
2019-02-05 16:10:16 +00:00
Brian Vaughn 98eb5ae531
TestRenderer toJSON should not expose the Array wrapper Suspense uses for hidden trees (#14392) 2018-12-05 11:09:51 -08:00
Sebastian Markbåge c954efa70f
Remove `import * as` pattern from the codebase (#14282)
Whenever we do this, Rollup needs to materialize this as an object.
This causes it to also add the Babel compatibility property which is
unnecessary bloat. However, since when we use these, we leak the object
this often also deopts any compiler optimizations.

If we really need an object we should export default an object.

Currently there is an exception for DOMTopLevelEventTypes since
listing out the imports is a PITA and it doesn't escape so it should
get properly inlined. We should probably move to a different pattern
to avoid this for consistency though.
2018-11-19 15:32:54 -08:00
Sebastian Markbåge fd1256a561
Add Debug Tools Package for Introspection of Hooks (#14085)
* Add debug tools package

* Add basic implementation

* Implement inspection of the current state of hooks using the fiber tree

* Support useContext hooks inspection by backtracking from the Fiber

I'm not sure this is safe because the return fibers may not be current
but close enough and it's fast.

We use this to set up the current values of the providers.

* rm copypasta

* Use lastIndexOf

Just in case. I don't know of any scenario where this can happen.

* Support ForwardRef

* Add test for memo and custom hooks

* Support defaultProps resolution
2018-11-05 10:02:59 -08:00
Andrew Clark cbbc2b6c4d
[Synchronous Suspense] Suspending a class outside concurrent mode (#13926)
* [Synchronous Suspense] Suspending a class outside concurrent mode

When a class component suspends during mount outside concurrent mode,
change the tag so it's not mistaken for a completed component. For
example, we should not call componentWillUnmount if it is deleted.

* PR nits
2018-10-23 11:36:56 -07:00
Dan Abramov 769b1f270e
pure -> memo (#13905) 2018-10-20 12:46:23 -04:00
Sebastian Markbåge 15b11d23f9
Allow arbitrary types to be wrapped in pure (#13903)
* Allow arbitrary types to be wrapped in pure

This creates an outer fiber that container the pure check and an inner
fiber that represents which ever type of component.

* Add optimized fast path for simple pure function components

Special cased when there are no defaultProps and it's a simple function
component instead of class. This doesn't require an extra fiber.

We could make it so that this also works with custom comparer but that
means we have to go through one extra indirection to get to it.
Maybe it's worth it, donno.
2018-10-20 00:32:16 -07:00
Sebastian Markbåge 95a313ec0b Unfork Lazy Component Branches (#13902)
* Introduce elementType field

This will be used to store the wrapped type of an element. E.g. pure and
lazy.

The existing type field will be used for the unwrapped type within them.

* Store the unwrapped type on the type field of lazy components

* Use the raw tags for lazy components

Instead, we check if the elementType and type are equal to test if
we need to resolve props. This is slightly slower in the normal case
but will yield less code and branching.

* Clean up lazy branches

* Collapse work tag numbering

* Split IndeterminateComponent out from Lazy

This way we don't have to check the type in a hacky way in the
indeterminate path. Also, lets us deal with lazy that resolves to
indeterminate and such.

* Missing clean up in rebase
2018-10-19 22:22:45 -07:00
Andrew Clark dac9202a9c
Hide timed-out children instead of deleting them so their state is preserved (#13823)
* Store the start time on `updateQueue` instead of `stateNode`

Originally I did this to free the `stateNode` field to store a second
set of children. I don't we'll need this anymore, since we use fragment
fibers instead. But I still think using `updateQueue` makes more sense
so I'll leave this in.

* Use fragment fibers to keep the primary and fallback children separate

If the children timeout, we switch to showing the fallback children in
place of the "primary" children. However, we don't want to delete the
primary children because then their state will be lost (both the React
state and the host state, e.g. uncontrolled form inputs). Instead we
keep them mounted and hide them. Both the fallback children AND the
primary children are rendered at the same time. Once the primary
children are un-suspended, we can delete the fallback children — don't
need to preserve their state.

The two sets of children are siblings in the host environment, but
semantically, for purposes of reconciliation, they are two separate
sets. So we store them using two fragment fibers.

However, we want to avoid allocating extra fibers for every placeholder.
They're only necessary when the children time out, because that's the
only time when both sets are mounted.

So, the extra fragment fibers are only used if the children time out.
Otherwise, we render the primary children directly. This requires some
custom reconciliation logic to preserve the state of the primary
children. It's essentially a very basic form of re-parenting.

* Use `memoizedState` to store various pieces of SuspenseComponent's state

SuspenseComponent has three pieces of state:

- alreadyCaptured: Whether a component in the child subtree already
suspended. If true, subsequent suspends should bubble up to the
next boundary.
- didTimeout: Whether the boundary renders the primary or fallback
children. This is separate from `alreadyCaptured` because outside of
strict mode, when a boundary times out, the first commit renders the
primary children in an incomplete state, then performs a second commit
to switch the fallback. In that first commit, `alreadyCaptured` is
false and `didTimeout` is true.
- timedOutAt: The time at which the boundary timed out. This is separate
from `didTimeout` because it's not set unless the boundary
actually commits.


These were previously spread across several fields.

This happens to make the non-strict case a bit less hacky; the logic for
that special case is now mostly localized to the UnwindWork module.

* Hide timed-out Suspense children

When a subtree takes too long to load, we swap its contents out for
a fallback to unblock the rest of the tree. Because we don't want
to lose the state of the timed out view, we shouldn't actually delete
the nodes from the tree. Instead, we'll keep them mounted and hide
them visually. When the subtree is unblocked, we un-hide it, having
preserved the existing state.

Adds additional host config methods. For mutation mode:

- hideInstance
- hideTextInstance
- unhideInstance
- unhideTextInstance

For persistent mode:

- cloneHiddenInstance
- cloneUnhiddenInstance
- createHiddenTextInstance

I've only implemented the new methods in the noop and test renderers.
I'll implement them in the other renderers in subsequent commits.

* Include `hidden` prop in noop renderer's output

This will be used in subsequent commits to test that timed-out children
are properly hidden.

Also adds getChildrenAsJSX() method as an alternative to using
getChildren(). (Ideally all our tests would use test renderer #oneday.)

* Implement hide/unhide host config methods for DOM renderer

For DOM nodes, we hide using `el.style.display = 'none'`.

Text nodes don't have style, so we hide using `text.textContent = ''`.

* Implement hide/unhide host config methods for Art renderer

* Create DOM fixture that tests state preservation of timed out content

* Account for class components that suspend outside concurrent mode

Need to distinguish mount from update. An unfortunate edge case :(

* Fork appendAllChildren between persistent and mutation mode

* Remove redundant check for existence of el.style

* Schedule placement effect on indeterminate components

In non-concurrent mode, indeterminate fibers may commit in an
inconsistent state. But when they update, we should throw out the
old fiber and start fresh. Which means the new fiber needs a
placement effect.

* Pass null instead of current everywhere in mountIndeterminateComponent
2018-10-18 15:37:16 -07:00
Dan Abramov 40a521aa72
Terminology: Functional -> Function Component (#13775)
* Terminology: Functional -> Function Component

* Drop the "stateless" (functions are already stateless, right?)
2018-10-04 22:44:46 +01:00
Andrew Clark a0733fe13d
pure (#13748)
* pure

A higher-order component version of the `React.PureComponent` class.
During an update, the previous props are compared to the new props. If
they are the same, React will skip rendering the component and
its children.

Unlike userspace implementations, `pure` will not add an additional
fiber to the tree.

The first argument must be a functional component; it does not work
with classes.

`pure` uses shallow comparison by default, like `React.PureComponent`.
A custom comparison can be passed as the second argument.

Co-authored-by: Andrew Clark <acdlite@fb.com>
Co-authored-by: Sophie Alpert <sophiebits@fb.com>

* Warn if first argument is not a functional component
2018-09-27 15:25:38 -07:00
Dominic Gannaway 0dc0ddc1ef
Rename AsyncMode -> ConcurrentMode (#13732)
* Rename AsyncMode -> ConcurrentMode
2018-09-26 17:13:02 +01:00
Brian Ng 970a34baed Bump babel-eslint and remove flow supressions (#13727) 2018-09-25 22:48:31 +01:00
Dan Abramov 144328fe81
Enable no-use-before-define rule (#13606) 2018-09-10 16:15:18 +01:00
Héctor Ramos b87aabdfe1
Drop the year from Facebook copyright headers and the LICENSE file. (#13593) 2018-09-07 15:11:23 -07:00
Sophie Alpert 340bfd9393
Rename ReactTypeOfWork to ReactWorkTags, ReactTypeOfSideEffect to ReactSideEffectTags (#13476)
* Rename ReactTypeOfWork to ReactWorkTags

And `type TypeOfWork` to `type WorkTag`.

* Rename ReactTypeOfSideEffect too
2018-08-26 13:40:27 -07:00
Andrew Clark 5031ebf6be
Accept promise as element type (#13397)
* Accept promise as element type

On the initial render, the element will suspend as if a promise were
thrown from inside the body of the unresolved component. Siblings should
continue rendering and if the parent is a Placeholder, the promise
should be captured by that Placeholder.

When the promise resolves, rendering resumes. If the resolved value
has a `default` property, it is assumed to be the default export of
an ES module, and we use that as the component type. If it does not have
a `default` property, we use the resolved value itself.

The resolved value is stored as an expando on the promise/thenable.

* Use special types of work for lazy components

Because reconciliation is a hot path, this adds ClassComponentLazy,
FunctionalComponentLazy, and ForwardRefLazy as special types of work.
The other types are not supported, but wouldn't be placed into a
separate module regardless.

* Resolve defaultProps for lazy types

* Remove some calls to isContextProvider

isContextProvider checks the fiber tag, but it's typically called after
we've already refined the type of work. We should get rid of it. I
removed some of them in the previous commit, and deleted a few more
in this one. I left a few behind because the remaining ones would
require additional refactoring that feels outside the scope of this PR.

* Remove getLazyComponentTypeIfResolved

* Return baseProps instead of null

The caller compares the result to baseProps to see if anything changed.

* Avoid redundant checks by inlining getFiberTagFromObjectType

* Move tag resolution to ReactFiber module

* Pass next props to update* functions

We should do this with all types of work in the future.

* Refine component type before pushing/popping context

Removes unnecessary checks.

* Replace all occurrences of _reactResult with helper

* Move shared thenable logic to `shared` package

* Check type of wrapper object before resolving to `default` export

* Return resolved tag instead of reassigning
2018-08-16 09:21:59 -07:00