PR Close #59661

fix(migrations): avoid applying the same replacements twice when cleaning up unused imports (#59656)

If a file ends up in multiple programs, the unused imports migration was counting it twice. This was fine since the string replacements were handling it correctly, but it was printing out incorrect data.

These changes rework the migration to de-duplicate the replacements and produce the data from the de-duplicated results.

PR Close #59656

This commit updates a flaky test to increase the amount of work (more `for` loop iterations) to minimize the chance of getting the same timestamp after that work.

PR Close #59653

Move TNode manipulation logic to its own file and update existing refereces.

PR Close #59601

Updates the HMR dependencies extraction logic to handle new expressions.
For example, `deps: [[new Optional(), dep]]`.

PR Close #59637

Updates the HMR dependencies extraction logic to handle conditional expressions.
For example, `providers: [condition ? providersA : providersB]`.

PR Close #59637

The component ID collision check tries to account for components being replaced by checking for the `type`, however that might not work during SSR.

These changes disable the warning since it's primarily useful on the browser anyways.

PR Close #59625

Fixes that the HMR dependency extraction logic wasn't accounting for parenthesized identifiers correctly.

PR Close #59644

Fixes that the async animations renderer didn't have the logic to clean up its style cache during HMR. This is identical to #59393.

Fixes #59640.

PR Close #59644

Fixes that we were filtering out the component itself from the set of dependencies when HMR is enabled, breaking self-referencing components.

Fixes #59632.

PR Close #59644

Currently during HMR we swap out the entire module definition (e.g. `MyComp.ɵcmp = newDef`). In standalone components and most module-based ones this works fine, however in some cases (e.g. circular dependencies) the compiler can produce a `setComponentScope` call for a module-based component. This call doesn't make it into the HMR replacement function, because it is defined in the module's file, not the component's. As a result, the dependencies of these components are cleared out upon replacement.

A secondary problem is that the `directiveDefs` and `pipeDefs` fields can save references to definitions that later become stale as a result of HMR.

These changes resolve both issues by:
1. Performing the replacement by copying the properties from the new definition onto the old one, while keeping it in place.
2. Preserving the initial `directiveDefs`, `pipeDefs` and `setInput`.

Fixes #59639.

PR Close #59644

See associated pull request for more information.

PR Close #59623

Both `:host` and `:host-context` work by looking for a specific character sequence that is terminated by `,` or `{` and replacing selectors inside of it with scoped versions. This is implemented as a regex which isn't aware of things like nested selectors. Normally this is fine for `:host`, because each `:host` produces one scoped selector which doesn't affect any child selectors, however it breaks down with `:host-context` which replaces each instance with two selectors. For example, if we have a selector in the form of `:host-context(.foo) a:not(.a, .b)`, the compiler ends up determining that `.a,` is the end selector and produces `.foo[a-host] a[contenta]:not(.a, .foo [a-host] a[contenta]:not(.a, .b) {}`.

These changes resolve the issue by splitting the CSS alogn top-level commas, processing the `:host-context` in them individually, and stiching the CSS back together.

PR Close #59276

This change refactors the Angular-specific linkedSignal implementation
such that its core logic can be shared with other frameworks.

PR Close #59501

When a component is created with shadow DOM encapsulation, we attach a shadow root to it. When the component is re-created during HMR, it was throwing an error because only one shadow root can be attached to a node at a time.

Since there's no way to detach a shadow root from a node, these changes resolve the issue by making a shallow clone of the element, replacing it and using the clone for any future updates.

Fixes #59588.

PR Close #59597

This change is required to resolve https://github.com/angular/angular-cli/pull/29248 and works in conjunction with https://github.com/angular/angular-cli/pull/29386. It ensures that HMR (Hot Module Replacement) functions correctly with `base href`, proxies, and other advanced development setups.

PR Close #59620

When HMR is enabled, we need to capture the dependencies used in a template and forward them to the HMR replacement function. One half of this process is static, meaning that we can't change it after the initial compilation. Tree shaking becomes a problem in such a case, because the user can change the template in a way that changes the set of dependencies which will start matching with the static part of the HMR code.

These changes disable the tree shaking when HMR is enabled to ensure that the dependencies stay stable.

Fixes #59581.

PR Close #59595

If a component injects `ViewContainerRef`, its `LView` gets wrapped in an empty `LContainer` and the container's host becomes the `LView`. The HMR logic wasn't accounting for this which meant that such components wouldn't be replaced.

Fixes #59592.

PR Close #59596

Improves readability.
PR Close #59568

In this commit, we clean up the reference to the function set by the environment initializer, as the function closure may capture injected elements and prevent them from being properly garbage collected.

PR Close #59598

This change refactor how the dynamically created component
deals with attributes in order to reuse the existing
setupStaticAttributes logic (instead of having specific
and similar code).

PR Close #59572

This commit updates a test setup to define a global `ngServerMode` correctly for a test that was emulating client-only behavior. The flag could've been set by prior tests and depending on its state, the test was acting differently.

PR Close #59584

This commit updates testing setup logic to apply correct `document` reference, which should be used by the runtime. Previously, the timing of that operation was less predictable and in some cases led to reusing document state from previous tests.

PR Close #59579

In this commit, we delete `_ejsa` when the app is destroyed, ensuring that no elements are still captured in the global list and are not prevented from being garbage collected.

PR Close #59492

In this commit, we switch from decorators (which also produce redundant metadata, such as in the `declareFactory`
instruction) to the `inject` function to drop the `ROUTER_FORROOT_GUARD` token in production. This token factory function is only in development mode but is still referenced in the constructor due to the `@Inject(ROUTER_FORROOT_GUARD)` decorator.

PR Close #59458

These changes aim to resolve the issue that prompted #59514. The animations module is a bit tricky for HMR, because it schedules the destruction of its renderer after the currently-running animations are done. If there are no running animations, the renderer gets destroyed next time around. This is a problem, because it means that the styles can stay around for a long time.

These changes resolve the issue by:
1. Moving the cleanup of the renderer to after the destruction of the old view. This ensures that the usual clean up flow has been kicked off.
2. Flushing the animations when a component is replaced to ensure that the renderer is cleaned up in a timely manner.

PR Close #59574

See associated pull request for more information.

PR Close #59571

This refactoring takes a step toward breaking down the
node_manipulation file into smaller, more focused files.

PR Close #59462

When the reactive `request` of a resource() notifies, it transitions to the
Loading state, fires the loader, and eventually transitions to Resolved.
With the prior implementation, a change of the `request` will queue the
effect, but the state remains unchanged until the effect actually runs. For
a brief period, the resource is in a state where the request has changed,
but the state has yet to update.

This is problematic if we want to use resources in certain contexts where we
care about the state of the resource in a synchronous way. For example, an
async validator backed by a resource might be checked after an update:

```
value.set(123);

if (validator.value()) {
  // value is still valid, even though the resource is dirty and will soon
  // flip to loading state (returning value(): undefined) while revalidating
}
```

To address this timing concern, `linkedSignal()` is used within the
`resource()` to synchronously transition the state in response to the
request changing. This ensures any followup reads see a consistent view of
the resource regardless of whether the effect has run.

This also addresses a race condition where `.set()` behaves differently on a
`resource()` depending on whether or not the effect has run.

PR Close #59024

Originally the `T` in `Resource<T>` represented the resolved type of the
resource, and `undefined` was explicitly added to this type in the `.value`
signal. This turned out to be problematic, as it wasn't possible to write a
type for a resource which didn't return `undefined` values. Such a type is
useful for 2 reasons:

1. to support narrowing of the resource type when `Resource.hasValue()`
   returns `true`.

2. for resources which use a different value instead of `undefined` to
   represent not having a value (for example, array resources which want to
   use `[]` as their default).

Instead, this commit changes `resource()` and `rxResource()` to return an
explicit `ResourceRef<T|undefined>`, and removes the union with `undefined`
from all types related to the resource's value. This way, it's trivially
possible to write `Resource<T>` to represent resources where `.value` only
returns `T`.

`hasValue()` then actually works to perform narrowing, by narrowing the
resource type to `Exclude<T, undefined>`.

PR Close #59024

Prevent leaking signal reads and exceptions from a custom `equal`
function of a producer `computed()` to a consumer.

Upstream https://github.com/tc39/proposal-signals/pull/90 with a notable
change: Angular does **not** track reactive reads in custom `equal`
implementations.

PR Close #55818

This commit updates the linkedSignal documentation around
the quality function option.

Fixes #59094

PR Close #59532

fixes #59538

PR Close #59539

Fixes that in some cases the HMR replacement function was being run outside the zone which meant that change detection would break down after a replacement.

Fixes #59559.

PR Close #59562

Rolls back the changes from #59514 because they ended up being breaking in 1P. We can revisit the internal fix in a different way.

Fixes #59558.

PR Close #59557

The test in question was very flaky on CI, example run:
https://github.com/angular/angular/actions/runs/12805645683/job/35702462974?pr=59557

Disabling as it is causing productivity loose for the team.

PR Close #59561

This is first of a series of refactorings that moves code
around such that logic from the shared instruction file
is dispatched to the relevant functional parts.

PR Close #59453