If a directive has an input declared as `dismissible = input<boolean>(true, {transform: booleanAttribute});` then the following templates were not compiling:
```
<div directiveName dismissible="true"></div>
<div directiveName dismissible></div>
```
This commit fixes the issue, without breaking contravariant consumers.
This is a follow-up to #67997, which allowed explicit read generics with input transforms, such as `input<boolean>(false, {transform: booleanAttribute})`.
That fixed the declaration, but static template attributes like `dismissible="true"` and bare `dismissible` were still checked as strings against the read type. Allow the fallback write type to include static attribute strings so these template forms compile.
Introduce a custom `set` option in `linkedSignal` options to allow overriding and customizing the default write-back behavior of writable signals. This lets developers route updates back to the source of truth (e.g., converting Fahrenheit back to Celsius) or perform other side effects like updating properties inside a parent signal.
Additionally, the custom callback receives the standard signal setter as its second parameter (`rawSet`) to allow direct internal mutation if desired.
Fixes#59665
TAG=agy
CONV=addbb5c4-4233-49e8-b844-6f732d7d5c72
Using explicit single generic arguments with transforms (for example, input<boolean>(false, {transform: booleanAttribute})) previously failed overload resolution.
Before this fix, type-checking produced:
````
✘ [ERROR] TS2769: No overload matches this call.
Overload 1 of 5, '(initialValue: boolean, opts?: InputOptionsWithoutTransform<boolean> | undefined): InputSignal<boolean>', gave the following error.
Type '(value: unknown) => boolean' is not assignable to type 'undefined'.
Overload 2 of 5, '(initialValue: undefined, opts: InputOptionsWithoutTransform<boolean>): InputSignal<boolean | undefined>', gave the following error.
Argument of type 'true' is not assignable to parameter of type 'undefined'. [plugin angular-compiler]
```
This change adds specialized overloads for explicit read generics.
Currently it's easy to make a mistake when accessing properties on `SimpleChanges`, because the keys aren't typed. These changes add an optional generic to the interface so that users can get a compilation error if they make a typo.
A few things to note:
1. The generic argument is optional and we revert to the old behavior if one isn't passed for backwards compatibility.
2. All of the keys are optional, because they aren't guaranteed to be present for any `ngOnChanges` invocation.
3. We unwrap the values of input signals to match the behavior at runtime.
Fixes#17560.
PR Close#64535
This commit adds type inference tests for `linkedSignal` usages, to capture their behavior w.r.t.
type inference. Note that there's some situations where type inference doesn't work as you might
expect/hope; these have been included to capture their behavior but may be revisited in the future
if the inference capabilities are expanded for this scenario.
Closes#60423
PR Close#60857
The original effect design for Angular had one "bucket" of effects, which
are scheduled on the microtask queue. This approach got us pretty far, but
as developers have built more complex reactive systems, we've hit the
limitations of this design.
This commit changes the nature of effects significantly. In particular,
effects created in components have a completely new scheduling system, which
executes them as a part of the change detection cycle. This results in
behavior similar to that of nested effects in other reactive frameworks. The
scheduling behavior here uses the "mark for traversal" flag
(`HasChildViewsToRefresh`). This has really nice behavior:
* if the component is dirty already, effects run following preorder hooks
(ngOnInit, etc).
* if the component isn't dirty, it doesn't get change detected only because
of the dirty effect.
This is not a breaking change, since `effect()` is in developer preview (and
it remains so).
As a part of this redesigned `effect()` behavior, the `allowSignalWrites`
flag was removed. Effects no longer prohibit writing to signals at all. This
decision was taken in response to feedback / observations of usage patterns,
which showed the benefit of the restriction did not justify the DX cost.
The new effect timing is not yet enabled - a future PR will flip the flag.
PR Close#56501
This commit introduces an overload for `input` to accept `undefined` as initial value if only
options are needed to be provided, inferring an input of type `T|undefined`. Prior to this change,
the type argument as specified needed to include `|undefined` explicitly even though that isn't
necessary when passing options isn't needed.
Relates to #53909
PR Close#57621
Since we aren't using clang anymore, we can remove the comments and the workarounds that were in place to prevent it from doing the wrong thing.
PR Close#55750
Ensures that all of the functions intended to be run in initializers are in an injection context. This is a stop-gap until we have a compiler diagnostic for it.
PR Close#54761
A model signal is technically an output, at runtime and conceptually.
This commit re-uses the shared output ref logic and ensures the
interfaces match.
PR Close#54650
Getting the typing for `ɵunwrapWritableSignal` just right was tricky so these changes add some tests to ensure that we don't regress.
Also reworks the type tester a bit to make it easier to find where to add new test files.
PR Close#54387
This updates some tests to use the public imports from `@angular/core` now that they are available,
and cleans up useless imports and inaccurate names.
PR Close#54334
This commit separates `InputSignal` for input signals with transforms.
The reason being that most of the time, signal inputs are not using
transforms and the generics are rather confusing.
Especially for users with inferred types displayed in their IDEs, the
input signal types are seemingly complex, even if no transform is used.
For this reason, we are introducing a new type called
`InputSignalWithTransform`. This type will be used for inputs with
transforms, while non-transform inputs just use `InputSignal`.
A notable fact is that `InputSignal` extends `InputSignalWithTransform`,
with the "identity transform". i.e. there is no transform. This allows
us to share the code for input signals. In practice, we don't expect
users to pass around `InputSignal`'s anyway.
PR Close#54053
Follow-up to #54002 that:
* Remove the `toString` implementation from the `primitives`.
* Guards the `toString` with `ngDevMode` and prints out the value.
PR Close#54079
Since signals are function, currently stringifying them reveals the implementation of the function. This can lead to confusion since it contains internal implementation details. These changes add static `toString` function to address the issue.
**Note:** it's tempting to have `toString` output the actual value of the signal, but that would encourage users not to call the function which will be problematic in the long run. That's why these changes are using a static string instead.
PR Close#54002
The new type testing infrastructure was introduced for the input-as-signals
authoring functions. This commit modifies this infrastructure to make it more
generic and support queries-as-signals.
PR Close#53829
Enables signal inputs for existing Zone based components.
This is a next step we are taking to bring signal inputs earlier to the Angular community.
The goal is to enable early access for the ecosystem to signal inputs, while we are continuing
development of full signal components as outlined in the RFC. This will allow the ecosystem
to start integrating signals more deeply, prepare for future migrations, and improves code quality
and DX for existing components (especially for OnPush).
Based on our work on full signal components, we've gathered more information and learned
new things. We've improved the API by introducing a way to intuitively declare required inputs,
as well as improved the API around initial values. We even support non-primitive initial values
as the first argument to the `input` function now.
```ts
@Directive({..})
export class MyDir {
firstName = input<string>(); // string|undefined
lastName = input.required<string>(); // string
age = input(0); // number
```
PR Close#53872
Adds tests that allow us to ensure that the `input` API works as
expected and that resulting return types match our expectations- without
silently regressing in the future, or missing potential edge-cases.
Testing signatures is hard because of covariance and contravariance,
especially when it comes to the different semantics of `ReadT` and
`WriteT` of input signals. We enable reliable testing by validating the
`d.ts` of the "fake directive class". This ensures clear results,
compared to relying on e.g. type assertions that might
accidentally/silently pass due to covariance/contravariance or
biavariance in the type system.
PR Close#53571
cexbrayat