Two-way bindings are meant to represent a property binding to an input and an event binding to an output, e.g. `[(ngModel)]="foo"` represents `[ngModel]="foo" (ngModelChange)="foo = $event"`. Previously due to a quirk in the template parser, we accidentally supported unassignable expressions in two-way bindings.
In #54154 the quirk was fixed, but we kept support or some common expression because of internal usages. Now the internal usages have been cleaned up so the backwards-compatibility code can be deleted.
Externally a migration was added in #54630 that will automatically fix any places that depended on the old behavior.
BREAKING CHANGE:
Angular only supports writable expressions inside of two-way bindings.
PR Close#55342
Previously the input flags were being generated as a reference to an enum member for better readability and under the assumption that minifiers would inline the values. That doesn't appear to be the case so these changes switch to using the literal values instead.
PR Close#55215
This commit updates the logic for preserving file overview comments
to be more reliable and less dependent on previous transforms.
Previously, with the old import manager, we had a utility called
`addImport` that always separated import statements and non-import
statements. This meant that the non-emitted statement from Tsickle
for the synthetic file-overview comments no longer lived at the
beginning of the file.
`addImports` tried to overcome this by adding another new non-emitted
statement *before* all imports. This then was later used by the
transform (or was assumed!) to attach the synthetic file overview
comments if the original tsickle AST Node is no longer at the top.
This logic can be improved, because the import manager shouldn't need to
bother about this fileoverview non-emitted statement, and the logic for
re-attaching the fileoverview comment should be local. This commit fixes
this and makes it a local transform.
PR Close#54819
This commit replaces `fake_core` with the real `@angular/core`
output. See previous commit for reasons.
Overall, this commit:
* Replaces references of `fake_core`
* Fixes tests that were testing Angular compiler detection that _would_
already be flagged by type-checking of TS directly. We keep these
tests for now, and add `@ts-ignore` to verify the Angular checks, in
case type checking is disabled in user applications- but it's worth
considering to remove these tests. Follow-up question/non-priority.
* Adds `@ts-ignore` to the tests for `defer` 1P because the property is
marked as `@internal` and now is (correctly) causing failures in the
compiler test environment.
* Fixes a couple of tests with typos, wrong properties etc that
previously weren't detected! A good sign.
PR Close#54650
As part of improving test safety of the compiler, I've noticed that
we have a special pass for detecting external `ModuleWithProviders`
where we detect the module type from an object literal.
This literal is structured like the following: `{ngModule: T}`. The
detection currently takes `T` directly, but in practice it should be
`typeof T` to satisfy the `ModuleWithProviders` type that is accepted
as part of `Component#imports`.
This commit adds support for this, so that we can fix the unit test
in preparation for using the real Angular core types in ngtsc tests.
PR Close#54650
Template pipeline is now the default template compiler.
A pair of source map tests is failing, related to DI in JIT mode; I will fix and re-enable these during the preview period.
PR Close#54571
This is based on an internal issue report.
An earlier change introduced a diagnostic to report cases where a symbol is in the `deferredImports` array, but is used eagerly. The check worked by looking through the deferred blocks in a scope, resolving the scope for each and checking if the element is within the scope. The problem is that resolving the scope won't work across scoped node boundaries. For example, if there's a control flow statement around the block or within the block but around the deferred dependency, it won't be able to resolve the scope since it isn't a direct child, e.g.
```
@if (true) {
@defer {
<deferred-dep/>
}
}
```
To fix this the case where the deferred block is inside a scoped node, I've changed the `R3BoundTarget.deferBlocks` to be a `Map` holding both the deferred block and its corresponding scope. Then to resolve the case where the dependency is within a scoped node inside the deferred block, I've added a depth-first traversal through the scopes within the deferred block.
PR Close#54499
This commit addresses a problem with PR #53695 that introduced support for default imports,
where the actual dynamic import used in the defer loading function continued to use the
symbol name, instead of `.default` for the dynamic import. This issue went unnoticed in the
testcase because a proper instance was being generated for the `ɵsetClassMetadataAsync` function,
but not the generated dependency loader function.
Fixes#54491
PR Close#54495
Currently, when two components are named `TestComponent`, and both would
use e.g. control flow. Templates would be generated by the compiler and
those would conflict at runtime because the names for the template
functions are not ensured to be unique.
This seems like a more general problem that could be tackled in the
future in the template pipeline by always using the `ConstantPool`, but
for now, we should be good already, given us ensuring the `baseName`'s are
always unique.
PR Close#54273
The deps tracker which is responsible to track orphan components does not work for classes mutated by custom decorator. Some work needed to make this happen (tracked in b/320536434). As a result, with option `forbidOrphanComponents` being true the deps tracker will falsely report any component as orphan if it or its NgModule have custom/duplicate decorators. So it is unsafe to use this option in the presence of custom/duplicate decorator and we disable it until it is made compatible. Note that applying custom/duplicate decorators to `@Injectable` classes is ok since these classes never make it into the deps tracker. So we excempt them.
PR Close#54139
Fixes that `@defer` blocks weren't recognizing default imports and generating the proper code for them. Default symbols need to be accessed through the `default` property in the `import` statement, rather than by their name.
PR Close#53695
In one of the earlier commits, the logic that appends `=$event` before parsing two-way bindings was removed and some validation was added to prevent unassignable expressions from being used. This ended up being problematic, because previously the parser was incorrectly allowing some invalid expressions which users came to depend on. For example, it transformed `[(value)]="a && a.b"` to `a && (a.b = $event)`.
These changes add some special cases for the common breakages that came up during the TGP.
PR Close#54154
Adds a compiler integration test for recognizing signal-based queries,
and emitting the expected output. Concrete output will be verified via
the compliance tests.
PR Close#53978
At the moment when unified host is selected (through option `_useHostForImportGeneration`) the compiler always generates alias reexports. Such reexports are mainly generated to satisfy strict dependency condition for generated files. Such condition is no longer the case for G3. At the same time, these alias reexports make it impossible to mix locally compiled targets with globally compiled targets. More precisely, a globally compiled target may not be able to consume a locally compiled target as its dependency since the former may import from the alias reexports which do not exist in the latter due to local compilation mode. So, to make global-local compilation interop possible, it is required to be able to turn off alias reexport generation.
PR Close#53937
Currently when someone declares a signal or non-signal input on a static
class member, the compiler will not yield any diagnostic. We can detect
these mistakes and report a diagnostic to help our users.
PR Close#53808
This commit changes the `HasTransform` flag to be only concerned with
decorator inputs. This allows us to automatically detect signal input
transforms without reliance on the flag, resulting in less complexity in
the compiler (as outlined in the design doc) and various other places,
while it also allows us to simplify JIT support for signal inputs
because there would be no need to capture the "hasTransform" state in
the decorator so that JIT can generate the according input flags.
`isSignal` will still persist as an input flag to allow for monomorphic
and highly efficient distinguishing at runtime, whether an input is
signal based or not. JIT transform will also need to propagate this
information to the runtime somehow.
PR Close#53808
Instead of computing the bit input flags at compile-time and inling
the final bit flag number, we will use the `InputFlags` enum directly.
This is a little more code in the compiler side, but will allow us to
have better debuggable development code, and also prevents problems
where runtime flag bitmasks differ from the compiler flag bitmasks.
This is in practice a noop for optimized applications as the enum values
would be inlined anyway. This matches existing compiler emit for e.g.
change detection strategy, or view encapsulation enums.
PR Close#53571
This commit introduces a new enum for capturing additional metadata
about inputs. Called `InputFlags`. These will be built up at compile
time and then propagated into the runtime logic, in a way that does
not require additional lookup dictionaries data structures, or
additional memory allocations for "common inputs" that do not have any flags.
The flags will incorporate information on whether an input is signal
based. This can then be used to avoid megamorphic accesses when such
input is set- as we'd not need to check the input field value. This also
avoids cases where an input signal may be used as initial value for an
input (as we'd not incorrectly detect the input as a signal input then).
The new metadata emit will be useful for incorporating additional
metadata for inputs, such as whether they are required etc (although
required inputs are a build-time only construct right now- but this is a
good illustration of why input flags can be useful). An alternative
could have been to have an additional boolean entry for signal inputs,
but allocating a number with more flexible input flags seems more future
proof and more reasonable andreadable.
More information on the megamorphic access when updating an input
signal
https://docs.google.com/document/d/1FpnFruviKb6BFTQfMAP2AMEqEB0FI7z-3mT_qm7lzX8/edit.
PR Close#53571
Fixes that the compiler was throwing an error if an ambient type is used inside of an input `transform` function. The problem was that the reference emitter was trying to write a reference to the ambient type's source file which isn't necessary.
Fixes#51424.
PR Close#51474
Adds the private `_enableBlockSyntax` flag that can be used by the language service to disable blocks on apps that aren't on Angular v17.
PR Close#52683
Prior to this change, the transform function would be referenced with a potentially
relative import into an external declaration file. Such imports are not portable
and should not be created in this context. This commit addresses the issue by threading
though the originally used module specifier by means of the `Reference` type.
Fixes#52324
PR Close#52437
This commit fixes an issue where using literal types in the arguments of an input coercion
function could result in emitting invalid output, due to an assumption that TypeScript makes
when emitting literal types. Specifically, it takes the literal's text from its containing
source file, but this breaks when the literal type node has been transplanted into a
different source file. This issue has surfaced in the type-check code generator and is
already being addressed there, so this commit moves the relevant `TypeEmitter` class
from the `typecheck` module to the `translator` module, such that it can be reused for
emitting types in the type translator.
Fixes#51672
PR Close#52437
A new flag added to the component's debug info to determine whether to throw runtime error (in dev mode) if component is being rendered without its NgModule. This flag is only set for non-standalone components.
PR Close#52061
Orphan component is an anti-pattern in Angular where a component is rendered while the NgModule declaring it is not installed. It is not easy to capture this scenario, specially in compile time. But it is possible to capture a special case in runtime where the component is being rendered without its NgModule even loaded into the browser. This change adds a flag in cli compiler option to enable such checking, and throwing a runtime exception if it happens. Note that such check is only done in dev mode.
Currently the check requires some generated code that is behind ngJitMode flag (i.e., call to ɵɵsetNgModuleScope), and the new flag can be set only if JIT mode is enabled (i.e., supportJitMode=true) otherwise an error will be thrown.
The orphan component is a main blocker for rolling out local compilation in g3. This option is needed for identifying and isolating such cases.
PR Close#52061
This commit updates `@defer` logic related to handling `after` and `minimum` parameters tree-shakable.
If `after` or `minimum` was used on a `@loading` or `@placeholder` blocks, compiler generates an extra argument for the `ɵɵdefer` instruction. This extra argument is a reference to a function that brings timer-related code.
PR Close#52042
Fixes that the compiler wasn't picking up pipes used inside defer block triggers as dependencies. We had implemented the `visitDeferredTrigger` visitor method, but it wasn't being called, because we weren't going through the `visitAll` method of the deferred block. We don't use `visitAll`, because child nodes have to be processed differently than the connected blocks and triggers.
Fixes#52068.
PR Close#52071
Reworks a few more places to output arrow functions instead of function declarations in order to reduce the amount of code we generate. Some of these places include:
* Factories in injectable definitions.
* Forward references.
* `dependencies` function in the component definition.
* `consts` function in the component definition.
PR Close#52010
Enables the new `@` block syntax by default by removing the `enabledBlockTypes` flags. There are still some internal flags that allow special use cases to opt out of the block syntax, like during XML parsing and when compiling older libraries (see #51979).
PR Close#51994
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
Reworks the `setClassMetadata` calls to generate arrow functions instead of full anonymous function declarations. While this won't have an effect on production bundle sizes, it's easier to read and it should lead to small parsing time gains in dev mode.
PR Close#51637
Adds support for template type checking of the `track` expression of a `for` loop block. Tracking expressions are treated as any other expression for type checking, however we have some special validation that doesn't allow them to access template variables and local references.
PR Close#51690
Adds support for template type checking inside `for` blocks. It is implemented by generating a JS `for...of` statement inside the TCB. The various loop variables (e.g. `$index`) are implemented by declaring a local number variable.
PR Close#51690
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
These changes build on top of #51514 to add support for advanced expressions inside the `track` parameter of `for` loop blocks. There are two different outputs that the compiler can generate:
1. If the tracking function only references the item or `$index`, the compiler generates a pure arrow function as a constant references in the `repeaterCreate` instruction.
2. If the tracking function has references to properties outside of the `for` loop block, the compiler will rewrite those references to go through `this` and generate a function declaration. The runtime will `bind` the declaration to the current component instance so that the rewritten `this` references are resolved correctly.
Advanced tracking expression come with the following limitations to ensure the best possible performance:
1. They can only reference the item, `$index` and properties directly on the component instance. This means that there'll be an error when accessing this like local template variables and references. While we could get this to work, we would have to traverse the context tree at runtime which will degrade the performance of the loop, because it's a linear time operation that is performed on each comparison. Furthermore, allowing local references would require us re-evaluate the list when any one of them has changed.
2. Pipes aren't allowed inside the tracking function.
3. Object literals and pipes used inside the tracking expression will be recreated on each invocation.
PR Close#51618
`tsickle` is not used in any code paths in 3P and we can remove
this complexity. The `tsickle` npm package has not been released
in a while and we are risking breakages with e.g. future TypeScript
versions.
Note that the `ng_module` rule was updated to not emit through
tsickle at all. The tsickle in 1P is done directly by `tsc_wrapped`
and our code path in `compiler-cli` is not needed at all.
PR Close#50602
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
This commit updates compiler logic to generate the `setClassMetadataAsync` calls for components that used defer blocks. The `setClassMetadataAsync` function loads deferrable dependencies and invokes the `setClassMetadata` synchronously once everything is loaded. This change is needed to avoid eager references to deferrable symbols in component metadata in generated code.
PR Close#51182
This commit updates the logic to drop regular imports when all symbols that it brings can be defer-loaded.
The change ensures that there is no mix of regular and dynamic imports present in a source file.
PR Close#51171
Updates the TemplateDefinitionBuilder class to generate the `defer` instruction for `{#defer}` blocks. Also generates dependency function that would be invoked at runtime (with dynamic imports inside).
PR Close#51162
An internal compiler option named `supportJitMode` is now available for use by the Angular CLI.
This option currently controls the emit of NgModule selector scope information. This emitted
information is only needed in AOT mode when an application also uses JIT. However, AOT mode
combined with JIT mode is not currently supported nor will work in the Angular CLI. With
the Angular CLI, JIT mode is only supported if the entire application is built in JIT mode.
Without this option, the CLI needs to manually perform a code transform to remove the information
and also replicate TypeScript's import eliding. This is can be a complicated operation and must
be continually kept up to date with any changes to both the Angular compiler and TypeScript.
The introduction of this new option alleviates these concerns while also removing several build
time actions that would otherwise need to be performed on every application build.
PR Close#51007
Joey Perrott