This change treats all views attached to `ApplicationRef` as `OnPush`,
meaning that they have to be explicitly marked for check in order to be
refreshed when a tick happens. This prevents "accidentally" refreshing
views which have `Default` change detection as a side effect of running
change detection from an unrelated notification.
In addition, this change helps us achieve one of the big goals of the
project: that we can provide a testing experience which gives developers
more confidence that a component is zoneless-compatible. Because
`ComponentFixture` change detection is run through `ApplicationRef`
instead of `ChangeDetectorRef` when zoneless is enabled, this ensures
that the component under test has correctly been marked for check in
order to be updated. Without this, calling
`ComponentFixture.detectChanges` would allow a test to _force_ change
detection on a view when Angular would have otherwise not known that it
needed to be updated. Calling `ComponentFixture.detectChanges` on a component
which is not marked for check will now omit refreshing component view.
PR Close#55099
While we do want to discourage `fixture.detectChanges`, it is yet to be
determined how this should be accomplished (warning, documentation, etc.). At
the moment, not being able to disable the error at all is entirely
prohibitive for existing test suites to use zoneless change detection in
tests. We would much rather allow existing test suites to disable the
error and use the zoneless change detection than prevent them from using
it entirely until all the `detectChanges` calls have been fixed.
Calling `detectChanges` manually can hide errors related to change
detection timing, but it is even worse when the "PseudoApplication"
fixture used (since it runs change detection _only_ on the component
rather than through `ApplicationRef`).
PR Close#55098
This commit makes the zoneless scheduler (privately) available to applications that
have ZoneJS-based change detection. This would catch any changes of
interest (signal updates, `markForCheck` calls, attaching `Dirty` views)
that happen outside the Angular Zone.
See #53844 for additional information about why this is important.
More details to come in the a future commit that makes this a public option.
PR Close#54952
This change aligns the stability of `ComponentFixture` with that of
`ApplicationRef`, preventing confusing differences between the two as
more APIs start using the `PendingTasks` that may not be tracked by
`NgZone`.
BREAKING CHANGE: `ComponentFixture.whenStable` now matches the
`ApplicationRef.isStable` observable. Prior to this change, stability
of the fixture did not include everything that was considered in
`ApplicationRef`. `whenStable` of the fixture will now include unfinished
router navigations and unfinished `HttpClient` requests. This will cause
tests that `await` the `whenStable` promise to time out when there are
incomplete requests. To fix this, remove the `whenStable`,
instead wait for another condition, or ensure `HttpTestingController`
mocks responses for all requests. Try adding `HttpTestingController.verify()`
before your `await fixture.whenStable` to identify the open requests.
Also, make sure your tests wait for the stability promise. We found many
examples of tests that did not, meaning the expectations did not execute
within the test body.
In addition, `ComponentFixture.isStable` would synchronously switch to
true in some scenarios but will now always be asynchronous.
PR Close#54949
This is a follow-up to #53718 that applies the same logic to the
`autoDetect` feature of the fixture's host view. This now unifies the
logic between `ApplicationRef` and `ComponentFixture` autodetect.
BREAKING CHANGE: The `ComponentFixture` `autoDetect` feature will no
longer refresh the component's host view when the component is `OnPush`
and not marked dirty. This exposes existing issues in components which
claim to be `OnPush` but do not correctly call `markForCheck` when they
need to be refreshed. If this change causes test failures, the easiest
fix is to change the component to `ChangeDetectionStrategy.Default`.
PR Close#54824
This commit updates `ApplicationRef.tick` to use `detectChangesInternal` for root
views rather than go through the `ChangeDetectorRef.detectChanges` API
which refreshes the host view without first looking at whether the view
is `OnPush` and not dirty. The current behavior would hide errors in
`OnPush` components that do not correctly get marked for check and would
break when migrating to zoneless change detection because `markForCheck`
was never called so change detection was never scheduled.
The error would be surprising and blamed on switching to zoneless when in
reality the issue already exists and is a problem with the component not
calling `markForCheck`. However, this error is hidden today because
`ApplicationRef.tick` refresh host bindings unconditionally.
BREAKING CHANGE: `OnPush` views at the root of the application need to
be marked dirty for their host bindings to refresh. Previously, the host
bindings were refreshed for all root views without respecting the
`OnPush` change detection strategy.
PR Close#53718
PR Close#53718
The current behavior of `autoDetect` in `ComponentFixture` does not
match production very well. It has several flaws that make it an
insufficient change detection mechanism:
* It runs change detection for the component under test _after_ views
attached to the `ApplicationRef`. This can cause real behavior
differences that break in production, because tests can observe view
refreshes in the incorrect order (for example, a dialog refreshing
before the component which opened it).
* Because of the above ordering, render hooks registered during change
detection of the fixture views _will not execute at all_ because
`ApplicationRef.tick` already happen.
* It does not rerun change detection on the view tree if there are more
dirty views to refresh after the render hooks complete.
* It effectively hides/swallows errors from change detection inside the
`onMicrotaskEmpty` subscription by not reporting them to the error
handler. Instead, this error ends up being unhandled in the
subscription and rxjs throws these in a `setTimeout`.
All of the above are problematic but this commit _does not_ fix the
final point. Ideally, we can land this in a future change but this
requires additional internal fixes. In the meantime, we have to juggle
special-case handling of the component fixture views within
`ApplicationRef.tick` using some special events to retain current
behavior and avoid errors from the fixture propagating to the `ErrorHandler`.
BREAKING CHANGE: The `ComponentFixture.autoDetect` feature now executes
change detection for the fixture within `ApplicationRef.tick`. This more
closely matches the behavior of how a component would refresh in
production. The order of component refresh in tests may be slightly
affected as a result, especially when dealing with additional components
attached to the application, such as dialogs. Tests sensitive to this
type of change (such as screenshot tests) may need to be updated.
Concretely, this change means that the component will refresh _before_
additional views attached to `ApplicationRef` (i.e. dialog components).
Prior to this change, the fixture component would refresh _after_ other
views attached to the application.
PR Close#54733
This commit updates TestBed logic to take into account situations when dependencies loaded within `@defer` blocks may import NgModules with providers. For such components, we invoke provider override function, which recursively inspects and applies the necessary changes.
PR Close#54667
The current behavior of `autoDetect` in `ComponentFixture` does not
match production very well. It has several flaws that make it an
insufficient change detection mechanism:
* It runs change detection for the component under test _after_ views
attached to the `ApplicationRef`. This can cause real behavior
differences that break in production, because tests can observe view
refreshes in the incorrect order (for example, a dialog refreshing
before the component which opened it).
* Because of the above ordering, render hooks registered during change
detection of the fixture views _will not execute at all_ because
`ApplicationRef.tick` already happen.
* It does not rerun change detection on the view tree if there are more
dirty views to refresh after the render hooks complete.
* It effectively hides/swallows errors from change detection inside the
`onMicrotaskEmpty` subscription by not reporting them to the error
handler. Instead, this error ends up being unhandled in the
subscription and rxjs throws these in a `setTimeout`.
All of the above are problematic but this commit _does not_ fix the
final point. Ideally, we can land this in a future change but this
requires additional internal fixes. In the meantime, we have to juggle
special-case handling of the component fixture views within
`ApplicationRef.tick` using some special events to retain current
behavior and avoid errors from the fixture propagating to the `ErrorHandler`.
breaking note for future when isG3 flag condition is removed for v18:
The `ComponentFixture.autoDetect` feature now executes
change detection for the fixture within `ApplicationRef.tick`. This more
closely matches the behavior of how a component would refresh in
production. The order of component refresh in tests may be slightly
affected as a result, especially when dealing with additional components
attached to the application, such as dialogs. Tests sensitive to this
type of change (such as screenshot tests) may need to be updated.
PR Close#54354
When the zoneless scheduler is provided, we want to update the behavior
of `ComponentFixture` to address common issues and painpoints in testing.
Developers should never have to call `detectChanges` on a fixture
manually. Instead of calling `detectChanges` after performing an
action that updates state and requies a template refresh, developers
should wait for change detection to run because the update needs to also have
notified the scheduler. If this was not the case, the component would
not work correctly in the application. Calling `detectChanges` to force
an update could hide real bugs.
This commit also updates the zoneless tests to uses `ComponentFixture`
instead of manually attaching to the `ApplicationRef` and rewriting a
lot of the helpers (`getDebugNode`, `isStable` as a value, `whenStable` as a
Promise).
PR Close#54024
Prior to this commit, `TestBed` would require tests call `flushEffects`
or `fixture.detectChanges` in order to execute effects. In general, we
want to discourage authoring tests like this because it makes the timing
of change detection and effects differ from what happens in the
application. Instead, developers should perform actions and `await` (or
`flush`/`tick` when using `fakeAsync`) some `Promise` so that Angular
can react to the changes in the same way that it does in the
application.
Note that this still _allows_ developers to flush effects synchronously
with `flushEffects` and `detectChanges` but also enables the <action>,
`await` pattern described above.
PR Close#53843
The `afterRender` hooks currently run after `ApplicationRef.tick` but
also run after any call to `ChangeDetectorRef.detectChanges`. This is
problematic because code which uses `afterRender` cannot expect the
component it's registered from to be rendered when the callback
executes. If there is a call to `ChangeDetectorRef.detectChanges` before
the global change detection, that will cause the hooks to run earlier
than expected.
This behavior is somewhat of a blocker for the zoneless project. There
is plenty of application code that do things like `setTimeout(() =>
doSomethingThatExpectsComponentToBeRendered())`, `NgZone.onStable(() =>
...)` or `ApplicationRef.onStable...`. `ApplicationRef.onStable` is a
should likely work similarly, but all of these are really wanting an API
that is `afterRender` with the requirement that the hook runs after the
global render, not an individual CDRef instance.
This change updates the `afterRender` hooks to only run when
`ApplicationRef.tick` happens.
fixes#52429fixes#53232
PR Close#52455
The `ComponentFixture` code needlessly dances around the `ngZone` being
`null` when the `ComponentFixtureNoNgZone` option is set. Instead, it
can use the `NoopNgZone` to get the same effect without needing to have
checks all over the place for its presence.
PR Close#53670
The component fixture dependencies have to be passed in manually. This
is a bit annoying to manage as we expand which dependencies are needed.
Instead, we can run the constructor in the TestBed injection context and
move the dependencies into the component fixture code, as is done with
other constructors in Angular.
PR Close#53400
This commit updates the logic to preserve previous value of cached TView before applying overrides. This helps ensure that the next tests that uses the same component has correct provider info.
PR Close#52918
Currently, when a component is overriden using `TestBed.overrideComponent`, Angular retains calculated scope for that component (a set of components and directives used within a component). This may cause stale information to be used in tests in some cases. This commit updates the logic to reset overridden component scope, so it gets re-computed during the next invocation.
Resolves#52817.
PR Close#52916
When a component contains `@defer` blocks, Angular compiler generates the code to apply component metadata (from the `@Component` decorator) after resolving all dynamic dependencies. Currently, this function is invoked eagerly at runtime, which causes dynamic imports to be kicked off earlier than expected. With the change in this commit, Angular will start resolving async metadata when it becomes necessary during testing.
PR Close#52708
When an effect is created in a component constructor, it might read signals
which are derived from component inputs. These signals may be unreliable or
(in the case of the proposed input signals) may throw if accessed before the
component is first change detected (which is what makes required inputs
available).
Depending on the scenario involved, the effect may or may not run before
this initialization takes place, which isn't a great developer experience.
In particular, effects created during CD (e.g. via control flow) work fine,
as do effects created in bootstrap thanks to the sync CD it performs. When
an effect is created through dynamic component creation outside of CD though
(such as on router navigations), it runs before the component is first CD'd,
causing the issue.
In fact, in the signal components RFC we described how effects would wait
until ngOnInit for their first execution for exactly this reason, but this
behavior was never implemented as it was thought our effect scheduling
design made it unnecessary. This is true of the regular execution of effects
but the above scenario shows that *creation* of the effect is still
vulnerable. Thus, this logic is needed.
This commit makes effects sensitive to their creation context, by injecting
`ChangeDetectorRef` optionally. An effect created with an injector that's
tied to a component will wait until that component is initialized before
initially being scheduled. TestBed effect flushing is also adjusted to
account for the additional interaction with change detection.
PR Close#52473
The `ViewRef<T>` interface extends `InternalViewRef` and is already not
part of the public API. There is no need for the extra `InternalViewRef`
interface. This confusing setup is likely leftover from the types
necessary to support both Ivy and ViewEngine.
PR Close#52430
This commit updates the logic to ignore `after` and `minimum` conditions when `DeferBlockFixture.render` method is used in tests.
Resolves#52313.
PR Close#52314
This commit adds the logic to cleanup all triggers once defer block is triggered.
When a trigger is created, its cleanup function is stored alongside other defer block info. Prefetch and regular triggers are store in different slots, since we need to invoke them at different time.
PR Close#52291
This adds `generate_api_docs` targets to all of the packages for which we publish api reference docs. One known issue here is that any type information that comes from another package (e.g. router depending on core) currently resolve to `any` because the other sources are not available in the program. This can be tackled in a follow-up commit.
This commit also updates the install patch for `@angular/build-tools` to use the local version of compiler-cli.
PR Close#52034
Switches the syntax for blocks from `{#block}{/block}` to `@block {}` based on the feedback from the community.
Read more about the decision-making process in our blog: https://blog.angular.io/meet-angulars-new-control-flow-a02c6eee7843
The existing block types changed in the following ways:
**Conditional blocks:**
```html
<!-- Before -->
{#if cond}
Main content
{:else if otherCond}
Else if content
{:else}
Else content
{/if}
<!-- After -->
@if (cond) {
Main content
} @else if (otherCond) {
Else if content
} @else {
Else content
}
```
**Deferred blocks**
```html
<!-- Before -->
{#defer when isLoaded}
Main content
{:loading} Loading...
{:placeholder} <icon>pending</icon>
{:error} Failed to load
{/defer}
<!-- After -->
@defer (when isLoaded) {
Main content
} @loading {
Loading...
} @placeholder {
<icon>pending</icon>
} @error {
Failed to load
}
```
**Switch blocks:**
```html
<!-- Before -->
{#switch value}
{:case 1}
One
{:case 2}
Two
{:default}
Default
{/switch}
<!-- After -->
@switch (value) {
@case (1) {
One
}
@case (2) {
Two
}
@default {
Default
}
}
```
**For loops**
```html
<!-- Before -->
{#for item of items; track item}
{{item.name}}
{:empty} No items
{/for}
<!-- After -->
@for (item of items; track item) {
{{item.name}}
} @empty {
No items
}
```
PR Close#51891
Adds support for passing in `@Component.styles` as a string. Also introduces a new `styleUrl` property on `@Component` for providing a single stylesheet. This is more convenient for the most common case where a component only has one stylesheet associated with it.
PR Close#51715
Previously effects were queued as they became dirty, and this queue was
flushed at various checkpoints during the change detection cycle. The result
was that change detection _was_ the effect runner, and without executing CD,
effects would not execute. This leads a particular tradeoff:
* effects are subject to unidirectional data flow (bad for dx)
* effects don't cause a new round of CD (good/bad depending on use case)
* effects can be used to implement control flow efficiently (desirable)
This commit changes the scheduling mechanism. Effects are now scheduled via
the microtask queue. This changes the tradeoffs:
* effects are no longer limited by unidirectional data flow (easy dx)
* effects registered in the Angular zone will trigger CD after they run
(same as `Promise.resolve` really)
* the public `effect()` type of effect probably isn't a good building block
for our built-in control flow, and we'll need a new internal abstraction.
As `effect()` is in developer preview, changing the execution timing is not
considered breaking even though it may impact current users.
PR Close#51049
Fixes that there was code duplication between the primary entry-point,
the testing entry-point and the rxjs-interop entry-point.
This code duplication resulted in additional code size (really
neglibible here because rxjs-interop did not duplicate large parts of
core, and `testing` is not used in production).
On the other hand though, the duplication resulted in a subtle JIT
dependency tracking issue due to the `depsTracker` no longer being a
singleton. This caused test failures as in:
https://github.com/angular/angular/pull/51415.
PR Close#51500
This commit updates TestBed to wait for async component metadata resolution before compiling components.
Async metadata is added by the compiler in case a component uses defer blocks, which contain deferrable
symbols.
PR Close#51182
The current change is done behind a flag which is set to false. So no change in code path took place here. In a followup PR the flag is changed to true which will make the actual change.
PR Close#51122
