This patch is a final major refactor in styling Angular.
This PR includes three main fixes:
All temporary state taht is persisted between template style/class application
and style/class application in host bindings is now removed.
Removes the styling() and stylingApply() instructions.
Introduces a "direct apply" mode that is used apply prop-based
style/class in the event that there are no map-based bindings as
well as property collisions.
PR Close#32259
PR Close#32596
This patch is a final major refactor in styling Angular.
This PR includes three main fixes:
All temporary state taht is persisted between template style/class application
and style/class application in host bindings is now removed.
Removes the styling() and stylingApply() instructions.
Introduces a "direct apply" mode that is used apply prop-based
style/class in the event that there are no map-based bindings as
well as property collisions.
PR Close#32259
BREAKING CHANGE:
Angular bazel users using protractor_web_test_suite from @angular/bazel npm package should now switch to the @bazel/protractor npm package.
This should impact very few users and the user's that are impacted have a very easy upgrade path to switch to fetching the protractor_web_test_suite rule via the @bazel/protractor npm package.
PR Close#32485
This PR fixes a critical performance issue where the language
service makes a MASSIVE number of filesystem calls when performing
module resolution.
This is because there is no caching. To make matters worse, module
resolution is performed for **every** program change (which means every
few keystrokes trigger a massive number of fs calls).
PR Close#32479
Prior to this commit, a directive with a selector `selector=".Titledir"` would not match an element like `div class="titleDir"` in Ivy whereas it would in VE. The same issue was present for `selector="[title=Titledir]` and `title="titleDir"`. This fixes the Ivy behavior by changing the matching algorithm to use lowercased values.
Note that some `render3` tests needed to be changed to reflect that the compiler generates lowercase selectors. These tests are in the process to be migrated to `acceptance` to use `TestBed` in another PR anyway.
PR Close#32548
Adds two acceptance tests to show a current difference in behavior between Ivy and VE.
A directive with a selector `.Titledir` matches an element with `class="titleDir"` in VE but not in Ivy.
Same thing for an attribute value.
PR Close#32548
Prior to this commit, the `previousOrParentTNode` was set to null after performing all operations within `refreshView` function. It's causing problems in more complex scenarios, for example when change detection is triggered during DI (see test added as a part of this commit). As a result, global state might be corrupted. This commit captures current value of `previousOrParentTNode` and restores it after `refreshView` call.
PR Close#32521
Replaces the `select` instruction with a new one called `advance`. Instead of the jumping to a specific index, the new instruction goes forward X amount of elements. The advantage of doing this is that it should generate code the compresses better.
PR Close#32516
The `goog.getMsg()` function requires placeholder names to be camelCased.
This is not the case for `$localize`. Here placeholder names need
match what is serialized to translation files.
Specifically such placeholder names keep their casing but have all characters
that are not in `a-z`, `A-Z`, `0-9` and `_` converted to `_`.
PR Close#32509
Prior to this change, the template source mapping details were always
built during the analysis phase, under the assumption that pre-analysed
templates would always correspond with external templates. This has
turned out to be a false assumption, as inline templates are also
pre-analyzed to be able to preload any stylesheets included in the
template.
This commit fixes the bug by capturing the template source mapping
details at the moment the template is parsed, which is either during the
preanalysis phase when preloading is available, or during the analysis
phase when preloading is not supported.
Tests have been added to exercise the template error mapping in
asynchronous compilations where preloading is enabled, similar to how
the CLI performs compilations.
Fixes#32538
PR Close#32544
Adds support for `styleUrls` definitions in the same way `templateUrl`
definitions are provided; clicking on styleUrl will take a user to the
respective file.
Unifies some code in determining a URL definition. We first check if a
url is a `templateUrl`; if it's not, we check that it's a `styleUrl` or
return no definitions.
PR Close#32464
This gives an overview of how much time is spent in each operation/phase
and makes it easy to do rough comparisons of how different
configurations or changes affect performance.
PR Close#32427
`ngcc` supports both synchronous and asynchronous execution. The default
mode when using `ngcc` programmatically (which is how `@angular/cli` is
using it) is synchronous. When running `ngcc` from the command line
(i.e. via the `ivy-ngcc` script), it runs in async mode.
Previously, the work would be executed in the same way in both modes.
This commit improves the performance of `ngcc` in async mode by
processing tasks in parallel on multiple processes. It uses the Node.js
built-in [`cluster` module](https://nodejs.org/api/cluster.html) to
launch a cluster of Node.js processes and take advantage of multi-core
systems.
Preliminary comparisons indicate a 1.8x to 2.6x speed improvement when
processing the angular.io app (apparently depending on the OS, number of
available cores, system load, etc.). Further investigation is needed to
better understand these numbers and identify potential areas of
improvement.
Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1
Original design doc: https://hackmd.io/uYG9CJrFQZ-6FtKqpnYJAA?view
Jira issue: [FW-1460](https://angular-team.atlassian.net/browse/FW-1460)
PR Close#32427
This commit adds a new `TaskQueue` implementation that supports
executing multiple tasks in parallel (while respecting interdependencies
between them).
This new implementation is currently not used, thus the behavior of
`ngcc` is not affected by this change. The parallel `TaskQueue` will be
used in a subsequent commit that will introduce parallel task execution.
PR Close#32427
This change does not alter the current behavior, but makes it easier to
introduce `TaskQueue`s implementing different task selection algorithms,
for example to support executing multiple tasks in parallel (while
respecting interdependencies between them).
Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1
PR Close#32427
Previously, `ngcc` needed to store some metadata related to the
processing of each entry-point. This metadata was stored in a `Map`, in
the form of `EntryPointProcessingMetadata` and passed around as needed.
After some recent refactorings, it turns out that this metadata (with
its only remaining property, `hasProcessedTypings`) was no longer used,
because the relevant information was extracted from other sources (such
as the `processDts` property on `Task`s).
This commit cleans up the code by removing the unused code and types.
PR Close#32427
In the past, a task's processability didn't use to be known in advance.
It was possible that a task would be created and added to the queue
during the analysis phase and then later (during the compilation phase)
it would be found out that the task (i.e. the associated format
property) was not processable.
As a result, certain checks had to be delayed, until a task's processing
had started or even until all tasks had been processed. Examples of
checks that had to be delayed are:
- Whether a task can be skipped due to `compileAllFormats: false`.
- Whether there were entry-points for which no format at all was
successfully processed.
It turns out that (as made clear by the refactoring in 9537b2ff8), once
a task starts being processed it is expected to either complete
successfully (with the associated format being processed) or throw an
error (in which case the process will exit). In other words, a task's
processability is known in advance.
This commit takes advantage of this fact by moving certain checks
earlier in the process (e.g. in the analysis phase instead of the
compilation phase), which in turn allows avoiding some unnecessary work.
More specifically:
- When `compileAllFormats` is `false`, tasks are created _only_ for the
first suitable format property for each entry-point, since the rest of
the tasks would have been skipped during the compilation phase anyway.
This has the following advantages:
1. It avoids the slight overhead of generating extraneous tasks and
then starting to process them (before realizing they should be
skipped).
2. In a potential future parallel execution mode, unnecessary tasks
might start being processed at the same time as the first (useful)
task, even if their output would be later discarded, wasting
resources. Alternatively, extra logic would have to be added to
prevent this from happening. The change in this commit avoids these
issues.
- When an entry-point is not processable, an error will be thrown
upfront without having to wait for other tasks to be processed before
failing.
PR Close#32427
Previously, `ngcc`'s programmatic API would run and complete
synchronously. This was necessary for specific usecases (such as how the
`@angular/cli` invokes `ngcc` as part of the TypeScript module
resolution process), but not for others (e.g. running `ivy-ngcc` as a
`postinstall` script).
This commit adds a new option (`async`) that enables turning on
asynchronous execution. I.e. it signals that the caller is OK with the
function call to complete asynchronously, which allows `ngcc` to
potentially run in a more efficient mode.
Currently, there is no difference in the way tasks are executed in sync
vs async mode, but this change sets the ground for adding new execution
options (that require asynchronous operation), such as processing tasks
in parallel on multiple processes.
NOTE:
When using the programmatic API, the default value for `async` is
`false`, thus retaining backwards compatibility.
When running `ngcc` from the command line (i.e. via the `ivy-ngcc`
script), it runs in async mode (to be able to take advantage of future
optimizations), but that is transparent to the caller.
PR Close#32427
This change does not alter the current behavior, but makes it easier to
introduce new types of `Executors` , for example to do the required work
in parallel (on multiple processes).
Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1
PR Close#32427
To persist some of its state, `ngcc` needs to update `package.json`
files (both in memory and on disk).
This refactoring abstracts these operations behind the
`PackageJsonUpdater` interface, making it easier to orchestrate them
from different contexts (e.g. when running tasks in parallel on multiple
processes).
Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1
PR Close#32427
In order to prevent `ngcc`'d packages (e.g. libraries) from getting
accidentally published, `ngcc` overwrites the `prepublishOnly` npm
script to log a warning and exit with an error. In case we want to
restore the original script (e.g. "undo" `ngcc` processing), we keep a
backup of the original `prepublishOnly` script.
Previously, running `ngcc` a second time (e.g. for a different format)
would create a backup of the overwritten `prepublishOnly` script (if
there was originally no `prepublishOnly` script). As a result, if we
ever tried to "undo" `ngcc` processing and restore the original
`prepublishOnly` script, the error-throwing script would be restored
instead.
This commit fixes it by ensuring that we only back up a `prepublishOnly`
script, iff it is not the one we created ourselves (i.e. the
error-throwing one).
PR Close#32427
This PR partially fixes a circular dependency problem whereby the
creation of a project queries Angular plugin for external files, but
the discovery of external files requires root files to be defined in a
Project. The right approach is to return empty array if Project has no
root files.
PR Close#32519
Logs a warning instead of throwing when running into a binding to an unknown property in JIT mode. Since we aren't using a schema for the runtime validation anymore, this allows us to support browsers where properties are unsupported.
PR Close#32463
Prior to this commit, listeners order was not preserved in case we coalesce them to avoid triggering unnecessary change detection cycles. For performance reasons we were attaching listeners to existing events at head (always using first listener as an anchor), to avoid going through the list, thus breaking the order in which listeners are registered. In some scenarios this order might be important (for example with `ngModelChange` and `input` listeners), so this commit updates the logic to put new listeners at the end of the list. In order to avoid performance implications, we keep a pointer to the last listener in the list, so adding a new listener takes constant amount of time.
PR Close#32484
We need to be clearer to developers who upgrade to v9 (next) and get this
error, why they have a problem and what they have to do about it.
Once we have a better CLI schematics story, where this import will be
included by default in new applications and a CLI migration will add it
when upgrading apps to v9, we could simplify or remove this error message.
PR Close#32491
Fixes an issue where Ivy incorrectly inserts items in the beginning of an `ngFor`, if the `ngFor` is set on an `ng-container`. The issue comes from the fact that we choose the `ng-container` comment node as the anchor point before which to insert the content, however the node might be after any of the nodes inside the container. These changes switch to picking out the first node inside of the container instead.
PR Close#32324
Historically bind() used to be a separate instruction. With a series of
refactoring it became a utility function but after recent code changes
it does not provide any valuable abstraction / help. On the contrary -
it can be seen as a performance problem (forces unnecessary comparison to
`NO_CHANGE` during change detection).
PR Close#32489
Prior to this commit, complex expressions (that require additional statements to be generated) were handled incorrectly in case they were used in attributes annotated with i18n flags. The problem was caused by the fact that extra statements were not appended to the temporary vars block, so they were missing in generated code. This commit updated the logic to use the `convertPropertyBinding`, which contains the necessary code to append extra statements. The `convertExpressionBinding` function was removed as it duplicates the `convertPropertyBinding` one (for the most part) and is no longer used.
PR Close#32309
Previously, when the ServiceWorker entered a degraded mode
(`EXISTING_CLIENTS_ONLY` or `SAFE_MODE`) it would remain in that mode
for the rest of the lifetime of ServiceWorker instance. Note that
ServiceWorkers are stopped by the browser after a certain period of
inactivity and a new instance is created as soon as the ServiceWorker
needs to handle an event (such as a request from the page). Those new
instances would start from the `NORMAL` mode.
The reason for this behavior is to err on the side of caution: If we
can't be sure why the ServiceWorker entered the degraded mode, it is
risky to try recovering on the same instance and might lead to
unexpected behavior.
However, it turns out that the `EXISTING_CLIENTS_ONLY` mode can only be
a result of some error happening with the latest version (e.g. a hash
mismatch in the manifest). Therefore, it is safe to recover from that
mode once a new, valid update is successfully installed and to start
accepting new clients.
This commit ensures that the mode is set back to `NORMAL`, when (a) an
update is successfully installed and (b) the current mode is
`EXISTING_CLIENTS_ONLY`.
Besides making the behavior more predictable (instead of relying on the
browser to decide when to terminate the current ServiceWorker instance
and create a new one), this change can also improve the developer
experience:
When people notice the error during debugging and fix it by deploying a
new version (either to production or locally), it is confusing that the
ServiceWorker will fetch and install the update (as seen by the requests
in the Network panel in DevTools) but not serve it to clients. With this
change, the update will be served to new clients as soon as it is
installed.
Fixes#31109
PR Close#31865
Previously, when the latest version was invalidated (e.g. due to a hash
mismatch), the SW entered a degraded `EXISTING_CLIENTS_ONLY` mode and
removed _all_ clients from its client-version map (essentially stopping
to serve any clients). Based on the code and surrounding comments, the
intention seems to have been to only remove clients that were on the
invalidated version, but keep other clients on older versions.
This commit fixes it by only unassigning clients what were on the latest
version and keep clients assigned to older versions.
PR Close#31865
Helper functions for making navigation requests were created in several
places inside the test suite, so this commit creates a top-level such
helper and uses that in all tests that need it.
PR Close#31865
The `latest` argument was only ever set to the value of comparing
`this.latestHash` with the `appVersion` hash, which is already computed
inside `versionFailed()`, so there is no reason to pass it as an
argument as well.
This doesn't have any impact on the current behavior of the SW.
PR Close#31865
Previously the template compiler would generate the same jsdoc comment
block for `$localize` as for `goog.getMsg()`. But it turns out that
the closure compiler will complain if the `@desc` and `@meaning`
tags are used for non-`getMsg()` calls.
For now we do not generate the comments for `$localize` calls. They are
not being used at the moment.
In the future it would be good to be able to extract the descriptions and
meanings from the `$localize` calls rather than relying upon the `getMsg()`
calls, which we do now. So we need to find a workaround for this constraint.
PR Close#32473
Prior to this fix if a `NO_CHANGE` value was assigned to a binding, or
an interpolation value rendererd a `NO_CHANGE` value, then the presence
of that value would cause the internal counter index values to not
increment properly. This patch ensures that this doesn't happen and
that the counter/bitmask values update accordingly.
PR Close#32143
This is a prerequisite to fix a bug in template completions whereby
completion of the string `ti` for the variable `title` results in
`tititle`.
This is because the position where the completion is requested is used
to insert the completion text. This is incorrect. Instead, a
`replacementSpan` should be used to indicate the span of text that needs
to be replaced. Angular's own `Completion` interface is insufficient to
hold this information. Instead, we should just use ts.CompletionEntry.
Also added string enum for `CompletionKind`, which is similar to
ts.ScriptElementKind but contains more info about HTML entities.
PR Close#32375
PR #32154 introduced `platform` and `any` for `providedIn` and the doc has a minor typo.
Also a test name was not changed accordingly to the refactoring done.
PR Close#32410
Since property binding metadata storage is guarded with the ngDevMode now
and several instructions were merged together, we can simplify the way we
store and read property binding metadata.
PR Close#32457
This commit changes the Angular compiler (ivy-only) to generate `$localize`
tagged strings for component templates that use `i18n` attributes.
BREAKING CHANGE
Since `$localize` is a global function, it must be included in any applications
that use i18n. This is achieved by importing the `@angular/localize` package
into an appropriate bundle, where it will be executed before the renderer
needs to call `$localize`. For CLI based projects, this is best done in
the `polyfills.ts` file.
```ts
import '@angular/localize';
```
For non-CLI applications this could be added as a script to the index.html
file or another suitable script file.
PR Close#31609
DebugElement.query also searches elements that may have been created
outside of Angular (ex: with `document.appendChild`). The current
behavior attempts to get the LContext of these nodes but throws an error
because the LContext does not exist.
PR Close#32361
Commit 904a2018e0 introduced a new migration for
undecorated classes with decorated Angular class members. Currently the migration
always calls `tree.beginUpdate` and `tree.commitUpdate` (even if there are no changes).
This causes unnecessary updates to be reported to developers running `ng update`. Once
an update is commited, the CLI will report the update regardless of whether any changes were
made or not.
This behavior can be observed in the `ng_update_migrations` integration test. See:
https://circleci.com/gh/angular/angular/438470#tests/containers/3. Notice how all
source files are denoted as `UPDATED` (even though there are no changes).
PR Close#32391
`simple-server.js` is vulnerable to a trivial path traversal attack, i.e. an
attacker can supply a path like `../../etc/passwd` to read arbitrary files on
the server. This change fixes the issue by properly resolving the path, and then
only serving files under the current directory (as intended).
This is not really a security issue, given the code is not part of Angular, but
rather just testing infrastructure for Angular itself, and the CI servers are
not expected to contain confidential information, but still worth fixing for
code hygiene.
PR Close#32392
This patch introduces a new micro benchmark that performance tests
against map-based style and class bindings in Ivy running together
on the same element.
PR Close#32401
This patch introduces a new micro benchmark that performance tests
against style and class bindings in Ivy running together on the same
element.
PR Close#32401
Extend the vocabulary of the `providedIn` to also include `'platform'` and `'any'`` scope.
```
@Injectable({
providedId: 'platform', // tree shakable injector for platform injector
})
class MyService {...}
```
PR Close#32154
Previously, any diagnostics reported during the compilation of an
entry-point would not be shown to the user, but either be ignored or
cause a hard crash in case of a `FatalDiagnosticError`. This is
unfortunate, as such error instances contain information on which code
was responsible for producing the error, whereas only its error message
would not. Therefore, it was quite hard to determine where the error
originates from.
This commit introduces behavior to deal with error diagnostics in a more
graceful way. Such diagnostics will still cause the compilation to fail,
however the error message now contains formatted diagnostics.
Closes#31977
Resolves FW-1374
PR Close#31996
The Angular compiler has an emulation system for various kinds of
filesystems and runs its testcases for all those filesystems. This
allows to verify that the compiler behaves correctly in all of the
supported platforms, without needing to run the tests on the actual
platforms.
Previously, the emulated Windows mode would normalize rooted paths to
always include a drive letter, whereas the native mode did not perform
this normalization. The consequence of this discrepancy was that running
the tests in native Windows was behaving differently compared to how
emulated Windows mode behaves, potentially resulting in test failures
in native Windows that would succeed for emulated Windows.
This commit adds logic to ensure that paths are normalized equally for
emulated Windows and native Windows mode, therefore resolving the
discrepancy.
PR Close#31996
Initially the `missing-injectable` migration was only being used
in google3. Wiring the migration up in the CLI migrations was
planned to be done in a follow-up.
PR Close#32349
If a project has nested projects that contain node_modules folders
that get processed by ngcc, it can be confusing when the ngcc
version changes since the error message is very generic:
```
The ngcc compiler has changed since the last ngcc build.
Please completely remove `node_modules` and try again.
```
This commit augments the error message with the path of
the entry-point that failed so that it is more obvious which
node_modules folder to remove.
BREAKING CHANGE:
This commit removes the public export of `hasBeenProcessed()`.
This was exported to be availble to the CLI integration but was never
used. The change to the function signature is a breaking change in itself
so we remove the function altogether to simplify and lower the public
API surface going forward.
PR Close#32396
Disambiguate the name of the Language Service Host used in constructing
a TypeScript Language Service Host by renaming the `host` property to
`tsLsHost`.
PR Close#32346
TestBed.get is not type safe, fixing it would be a massive breaking
change. The Angular team has proposed replacing it with TestBed.inject
and deprecate TestBed.get.
Deprecation from TestBed.get will come as a separate commit.
Issue #26491Fixes#29905
BREAKING CHANGE: Injector.get now accepts abstract classes to return
type-safe values. Previous implementation returned `any` through the
deprecated implementation.
PR Close#32200
Move generic test methods to `MockTypescriptHost` so they could be
shared across all tests.
This is in preparation for adding more tests to Hover when new features
get added.
PR Close#32378
Hovering over a selector, the QuickInfo display string is something
like:
```
(component) AppComponent
```
where `component` is the symbol kind.
Prior to this, there was no types to indicate the possible values of a
symbol. This PR creates an enum to represent that.
PR Close#32376
This commit fixes a bug introduced in the recent refactoring whereby
caches become stale when the program changes.
This is because StaticReflector keeps its own caches that are not
clearable. The previous refactoring tried to reuse the same instance,
leading to out-of-sync program state.
Clearing out the *entire* cache is very inefficient. Instead, we could
just invalidate the symbols in the files that have changed. This
requires changes to the API of StaticReflector, but put this on hold
until the refactoring of language service for Ivy commences.
PR closes https://github.com/angular/angular/issues/32301
PR Close#32357
Currently the undecorated classes migration decorates base classes if no
explicit constructor is defined on all classes in the inheritance chain.
We only want to decorate base classes which define a constructor that is
inherited. Additionally for best practice, all classes in between the class
that inherits the constructor and the one that defines it are also decorated.
PR Close#32319
The `undecorated-classes-with-di` migration currently creates invalid object literals from parsed
NGC metadata files if there are object literal properties with keys that contain special characters.
e.g. consider a decorated base class with a host binding using `[class.X]`. Currently the migration
parses and converts the metadata to TypeScript code but incorrectly uses `[class.X]` unquoted as
identifier.
PR Close#32319
Apparently the names of the bazel test targets in the schematics are
incorrect. This commit updates the target names to match their bazel
package name.
PR Close#32318
ec4381dd40 enabled Ivy by default. This is
problematic as migrations like `undecorated-classes-with-di` depend on the
`AngularCompilerProgram` (NGC) in order to perform the migration from
version 8 to version 9. In order to ensure that the migration always runs
with NGC (and doesn't get the `NgtscProgram`), we need to explicitly disable
ivy when creating the `@angular/compiler-cli` program for the migration.
PR Close#32318
Adds support for `getDefinitionAt` when called on a templateUrl
property assignment.
The currrent architecture for getting definitions is designed to be
called on templates, so we have to introduce a new
`getTsDefinitionAndBoundSpan` method to get Angular-specific definitions
in TypeScript files and pass a `readTemplate` closure that will read the
contents of a template using `TypeScriptServiceHost#getTemplates`. We
can probably go in and make this nicer in a future PR, though I'm not
sure what the best architecture should be yet.
Part of angular/vscode-ng-language-service#111
PR Close#32238
Previously, the `SwPush` API docs were using hard-coded code snippets.
This commit switches to using code snippets from an actual example app,
which ensures that the code shown in the docs will at least continue to
compile successfully.
PR Close#32139
Reworks the compiler to output the factories for directives, components and pipes under a new static field called `ngFactoryFn`, instead of the usual `factory` property in their respective defs. This should eventually allow us to inject any kind of decorated class (e.g. a pipe).
**Note:** these changes are the first part of the refactor and they don't include injectables. I decided to leave injectables for a follow-up PR, because there's some more cases we need to handle when it comes to their factories. Furthermore, directives, components and pipes make up most of the compiler output tests that need to be refactored and it'll make follow-up PRs easier to review if the tests are cleaned up now.
This is part of the larger refactor for FW-1468.
PR Close#31953
Binding metadata are only needed:
- for property bindings;
- when TestBed tests are being run.
This commit guards binding metadata storage with the ngDevMode flag
which saves ~6% of a proerty binding processing time in the production
mode (and reduces bundle size).
PR Close#32317
After a series of recent refactorings `enterView` and `leaveView` became
identical. This PR merges both into one concept of view selectio (similar
to a node selection). This reduces number of concepts and code size.
PR Close#32263
This commit removes all the (duplicated) logic of setting lView[BINDING_INDEX]
from `enterView`. `enterView` is on the critcal path perf-wise so we should
avoid having any logic in there and minimise memory read / write.
This simple refactoring in this PR reduces time spent in noop change detection
by ~12% (from ~800ms down to ~700ms on a local machine where measurements were
taken).
PR Close#32263
When ngcc is called for a specific entry-point, it has to determine
which dependencies to transitively process. To accomplish this, ngcc
traverses the full import graph of the entry-points it encounters, for
which it uses a dependency host to find all module imports. Since
imports look different in the various bundle formats ngcc supports, a
specific dependency host is used depending on the information provided
in an entry-points `package.json` file. If there's not enough
information in the `package.json` file for ngcc to be able to determine
which dependency host to use, ngcc would fail with an error.
If, however, the entry-point is not compiled by Angular, it is not
necessary to process any of its dependencies. None of them can have
been compiled by Angular so ngcc does not need to know about them.
Therefore, this commit changes the behavior to avoid recursing into
dependencies of entry-points that are not compiled by Angular.
In particular, this fixes an issue for packages that have dependencies
on the `date-fns` package. This package has various secondary
entry-points that have a `package.json` file only containing a `typings`
field, without providing additional fields for ngcc to know which
dependency host to use. By not needing a dependency host at all, the
error is avoided.
Fixes#32302
PR Close#32303
This PR makes finding class declarations properties in decorators are
applied to more generic to all properties that may be in a decorator,
and adds helper methods enabling getting the property assignment of a
property value and verifying that a property assignment is actually in a
decorator applied to a class.
This is done so that it will be easier to provide Angular definitions
for decorator properties moving forward. Most immediately, this will
provide decorator class verification for #32238.
PR Close#32252
The TemplateInfo type is an extension of AstResult, but it is not
necessary at all. Instead, improve the current interface for AstResult
by removing all optional fileds and include the TemplateSource in
AstResult instead.
PR Close#32250
Prior to this change, the `BINDING_INDEX` of a given lView was reset after processing a template. However change detection can be triggered as a result of View queries processing, thus leading to subsequent `refreshView` call (and executing a template), which in turn operates with the binding index that is not reset after the previous `refreshView` call. This commit updates the logic to reset binding index before we execute a template, so binding index is correct for instructions inside template function.
PR Close#32201
In ngc is was valid to set the "flatModuleOutFile" option to "null". This is sometimes
necessary if a tsconfig extends from another one but the "fatModuleOutFile" option
needs to be unset (note that "undefined" does not exist as value in JSON)
Now if ngtsc is used to compile the project, ngtsc will fail with an error because it
tries to do string manipulation on the "flatModuleOutFile". This happens because
ngtsc only skips flat module indices if the option is set to "undefined".
Since this is not compatible with what was supported in ngc and such exceptions
should be avoided, the flat module check is now aligned with ngc.
```
TypeError: Cannot read property 'replace' of null
at Object.normalizeSeparators (/home/circleci/project/node_modules/@angular/compiler-cli/src/ngtsc/util/src/path.js:35:21)
at new NgtscProgram (/home/circleci/project/node_modules/@angular/compiler-cli/src/ngtsc/program.js:126:52)
```
Additionally setting the `flatModuleOutFile` option to an empty string
currently results in unexpected behavior. No errors is thrown, but the
flat module index file will be `.ts` (no file name; just extension).
This is now also fixed by treating an empty string similarly to
`null`.
PR Close#32235
Previously, ngtsc attempted to use the .d.ts schema for HTML elements to
check bindings to DOM properties. However, the TypeScript lib.dom.d.ts
schema does not perfectly align with the Angular DomElementSchemaRegistry,
and these inconsistencies would cause issues in apps. There is also the
concern of supporting both CUSTOM_ELEMENTS_SCHEMA and NO_ERRORS_SCHEMA which
would have been very difficult to do in the existing system.
With this commit, the DomElementSchemaRegistry is employed in ngtsc to check
bindings to the DOM. Previous work on producing template diagnostics is used
to support generation of this different kind of error with the same high
quality of error message.
PR Close#32171
This commit adds a no-op test for exposing the bug in the way language
service handles CRLF line endings in templates.
There is no easy fix for now, but the test should be enabled once a fix
is in place.
PR Close#32245
This commit drops our custom, change-detection specific, equality comparison util
in favour of the standard Object.is which has desired semantics.
There are multiple advantages of this approach:
- less code to maintain on our end;
- avoid NaN checks if both values are equal;
- re-write NaN checks so we don't trigger V8 deoptimizations.
PR Close#32212
Angular hooks come after 2 flavours:
- init hooks (OnInit, AfterContentInit, AfterViewInit);
- check hooks (OnChanges, DoChanges, AfterContentChecked, AfterViewChecked).
We need to do more processing for init hooks to ensure that those hooks
are run once and only once for a given directive (even in case of errors).
As soon as all init hooks execute to completion we are only left with the
checks to execute.
It turns out that keeping track of the remaining init hooks to execute is
rather expensive (multiple LView flags reads, writes and checks). But we can
observe that non of this tracking is needed as soon as all init hooks are
completed.
This PR takes advantage of the above observations and splits hooks processing
functions into:
- init-specific (slower but less common);
- check-specific (faster and more common).
NOTE: there is code duplication in this PR and it is left like this intentinally:
hand-inlining this perf-critical code makes the view refresh process substentially
faster.
PR Close#32131
Currently, it's not possible to tree-shake away the
coordination layer between HammerJS and Angular's
EventManager. This means that you get the HammerJS
support code in your production bundle whether or
not you actually use the library.
This commit removes the Hammer providers from the
default platform_browser providers list and instead
provides them as part of a `HammerModule`. Apps on
Ivy just need to import the `HammerModule` at root
to turn on Hammer support. Otherwise all Hammer code
will tree-shake away. View Engine apps will require
no change.
BREAKING CHANGE
Previously, in Ivy applications, Hammer providers
were included by default. With this commit, apps
that want Hammer support must import `HammerModule`
in their root module.
PR Close#32203
Historically, the Angular Compiler has produced both native TypeScript
diagnostics (called ts.Diagnostics) and its own internal Diagnostic format
(called an api.Diagnostic). This was done because TypeScript ts.Diagnostics
cannot be produced for files not in the ts.Program, and template type-
checking diagnostics are naturally produced for external .html template
files.
This design isn't optimal for several reasons:
1) Downstream tooling (such as the CLI) must support multiple formats of
diagnostics, adding to the maintenance burden.
2) ts.Diagnostics have gotten a lot better in recent releases, with support
for suggested changes, highlighting of the code in question, etc. None of
these changes have been of any benefit for api.Diagnostics, which have
continued to be reported in a very primitive fashion.
3) A future plugin model will not support anything but ts.Diagnostics, so
generating api.Diagnostics is a blocker for ngtsc-as-a-plugin.
4) The split complicates both the typings and the testing of ngtsc.
To fix this issue, this commit changes template type-checking to produce
ts.Diagnostics instead. Instead of reporting a special kind of diagnostic
for external template files, errors in a template are always reported in
a ts.Diagnostic that highlights the portion of the template which contains
the error. When this template text is distinct from the source .ts file
(for example, when the template is parsed from an external resource file),
additional contextual information links the error back to the originating
component.
A template error can thus be reported in 3 separate ways, depending on how
the template was configured:
1) For inline template strings which can be directly mapped to offsets in
the TS code, ts.Diagnostics point to real ranges in the source.
This is the case if an inline template is used with a string literal or a
"no-substitution" string. For example:
```typescript
@Component({..., template: `
<p>Bar: {{baz}}</p>
`})
export class TestCmp {
bar: string;
}
```
The above template contains an error (no 'baz' property of `TestCmp`). The
error produced by TS will look like:
```
<p>Bar: {{baz}}</p>
~~~
test.ts:2:11 - error TS2339: Property 'baz' does not exist on type 'TestCmp'. Did you mean 'bar'?
```
2) For template strings which cannot be directly mapped to offsets in the
TS code, a logical offset into the template string will be included in
the error message. For example:
```typescript
const SOME_TEMPLATE = '<p>Bar: {{baz}}</p>';
@Component({..., template: SOME_TEMPLATE})
export class TestCmp {
bar: string;
}
```
Because the template is a reference to another variable and is not an
inline string constant, the compiler will not be able to use "absolute"
positions when parsing the template. As a result, errors will report logical
offsets into the template string:
```
<p>Bar: {{baz}}</p>
~~~
test.ts (TestCmp template):2:15 - error TS2339: Property 'baz' does not exist on type 'TestCmp'.
test.ts:3:28
@Component({..., template: TEMPLATE})
~~~~~~~~
Error occurs in the template of component TestCmp.
```
This error message uses logical offsets into the template string, and also
gives a reference to the `TEMPLATE` expression from which the template was
parsed. This helps in locating the component which contains the error.
3) For external templates (templateUrl), the error message is delivered
within the HTML template file (testcmp.html) instead, and additional
information contextualizes the error on the templateUrl expression from
which the template file was determined:
```
<p>Bar: {{baz}}</p>
~~~
testcmp.html:2:15 - error TS2339: Property 'baz' does not exist on type 'TestCmp'.
test.ts:10:31
@Component({..., templateUrl: './testcmp.html'})
~~~~~~~~~~~~~~~~
Error occurs in the template of component TestCmp.
```
PR Close#31952
When a template contains a binding without a value, the template parser
creates an `EmptyExpr` node. This would previously be translated into
an `undefined` value, which would cause a crash downstream as `undefined`
is not included in the allowed type, so it was not handled properly.
This commit prevents the crash by returning an actual expression for empty
bindings.
Fixes#30076Fixes#30929
PR Close#31594
This commit switches the default value of the enableIvy flag to true.
Applications that run ngc will now by default receive an Ivy build!
This does not affect the way Bazel builds in the Angular repo work, since
those are still switched based on the value of the --define=compile flag.
Additionally, projects using @angular/bazel still use View Engine builds
by default.
Since most of the Angular repo tests are still written against View Engine
(particularly because we still publish VE packages to NPM), this switch
also requires lots of `enableIvy: false` flags in tsconfigs throughout the
repo.
Congrats to the team for reaching this milestone!
PR Close#32219
This option makes ngc behave as tsc, and was originally implemented before
ngtsc existed. It was designed so we could build JIT-only versions of
Angular packages to begin testing Ivy early, and is not used at all in our
current setup.
PR Close#32219
Previously, `ngcc` assumed that if a format property was defined in
`package.json` it would point to a valid format-path (i.e. a file that
is an entry-point for a specific format). This is generally the case,
except if a format property is set to a non-string value (such as
`package.json`) - either directly in the `package.json` (which is unusual)
or in ngcc.config.js (which is a valid usecase, when one wants a
format property to be ignored by `ngcc`).
For example, the following config file would cause `ngcc` to throw:
```
module.exports = {
packages: {
'test-package': {
entryPoints: {
'.': {
override: {
fesm2015: undefined,
},
},
},
},
},
};
```
This commit fixes it by ensuring that only format properties whose value
is a string are considered by `ngcc`.
For reference, this regression was introduced in #32052.
Fixes#32188
PR Close#32205
Initially the plan was to have a migration that adds `@Injectable()` to
all pipes in a CLI project so that the pipes can be injected in Ivy
similarly to how it worked in view engine.
Due to the planned refactorings which ensure that `@Directive`, `@Component`
and `@Pipe` also have a factory definition, this migration is no longer
needed for Ivy. Additionally since it is already disabled (due to
572b54967c) and we have a more generic
migration (known as `missing-injectable)` that could do the same as
`injectable-pipe`, we remove the migration from the code-base.
PR Close#32184
The API of `@microsoft/api-extractor` changed in a minor version which is causes an error when using dts flattening downstream.
API wil be updated on master https://github.com/angular/angular/pull/32185
PR Close#32187
Fixes an error that is thrown by `ngTemplateOutlet` under Ivy when switching from a template to null and back to a template. The error is thrown because the reference to the previous ViewRef is never cleared and the directive tries to detach a view that has already been detached.
Fixes#32060.
PR Close#32160
During the dependency analysis phase of ngcc, imports are resolved to
files on disk according to certain module resolution rules. Since module
specifiers are typically missing extensions, or can refer to index.js
barrel files within a directory, the module resolver attempts several
postfixes when searching for a module import on disk. Module specifiers
that already include an extension, however, would fail to be resolved as
ngcc's module resolver failed to check the location on disk without
adding any postfixes.
Closes#32097
PR Close#32181
During the recursive processing of dependencies, ngcc resolves the
requested file to an actual location on disk, by testing various
extensions. For recursive calls however, the path is known to have been
resolved in the module resolver. Therefore, it is safe to move the path
resolution to the initial caller into the recursive process.
Note that this is not expected to improve the performance of ngcc, as
the call to `resolveFileWithPostfixes` is known to succeed immediately,
as the provided path is known to exist without needing to add any
postfixes. Furthermore, the FileSystem caches whether files exist, so
the additional check that we used to do was cheap.
PR Close#32181
This commit fixes many diagnostic tests have have incorrect/uncaught assertions.
Also added more assertions to make sure TS diagnostics are clear.
A few test util methods are removed to reduce clutter and improve readability.
PR Close#32161
Remove unnecessary private method `getDeclarationFromNode` and moved
some logic to utils instead so that it can be tested in isolation of the
Language Service infrastructure.
The use of typechecker to check the directive is also not necessary,
since resolve.getNonNormalizedDirectiveMetadata() will check if the
directive is actually an Angular entity.
PR Close#32156
TypeScript downlevels `for-of` loops for ES5 targets. As a result, generated output contains extra code, including a try-catch block, which has code size and performance implications. This is especially important for runtime code where we want to keep it as small as possible. This commit changes `for-of` loops in runtime code to regular `for` loops.
PR Close#32157
Bundle size changed in both zone.js(legacy) and zone-evergreen.js
- zone.js(legacy) package increased a little because the following feature and fixes.
1. #31699, handle MSPointer events PR
2. https://github.com/angular/zone.js/pull/1219 to add __zone_symbol__ customization support
- zone-evergreen.js package decreased because
1. the MSPointer PR only for legacy
2. the Object.defineProperty patch is moved to legacy #31660
PR Close#31975
ngcc needs to solve a unique problem when compiling typings for an
entrypoint: it must resolve a declaration within a .js file to its
representation in a .d.ts file. Since such .d.ts files can be used in deep
imports without ever being referenced from the "root" .d.ts, it's not enough
to simply match exported types to the root .d.ts. ngcc must build an index
of all .d.ts files.
Previously, this operation had a bug: it scanned all .d.ts files in the
.d.ts program, not only those within the package. Thus, if a class in the
program happened to share a name with a class exported from a dependency's
.d.ts, ngcc might accidentally modify the wrong .d.ts file, causing a
variety of issues downstream.
To fix this issue, ngcc's .d.ts scanner now limits the .d.ts files it
indexes to only those declared in the current package.
PR Close#32129
One of the compiler's tasks is to enumerate the exports of a given ES
module. This can happen for example to resolve `foo.bar` where `foo` is a
namespace import:
```typescript
import * as foo from './foo';
@NgModule({
directives: [foo.DIRECTIVES],
})
```
In this case, the compiler must enumerate the exports of `foo.ts` in order
to evaluate the expression `foo.DIRECTIVES`.
When this operation occurs under ngcc, it must deal with the different
module formats and types of exports that occur. In commonjs code, a problem
arises when certain exports are downleveled.
```typescript
export const DIRECTIVES = [
FooDir,
BarDir,
];
```
can be downleveled to:
```javascript
exports.DIRECTIVES = [
FooDir,
BarDir,
```
Previously, ngtsc and ngcc expected that any export would have an associated
`ts.Declaration` node. `export class`, `export function`, etc. all retain
`ts.Declaration`s even when downleveled. But the `export const` construct
above does not. Therefore, ngcc would not detect `DIRECTIVES` as an export
of `foo.ts`, and the evaluation of `foo.DIRECTIVES` would therefore fail.
To solve this problem, the core concept of an exported `Declaration`
according to the `ReflectionHost` API is split into a `ConcreteDeclaration`
which has a `ts.Declaration`, and an `InlineDeclaration` which instead has
a `ts.Expression`. Differentiating between these allows ngcc to return an
`InlineDeclaration` for `DIRECTIVES` and correctly keep track of this
export.
PR Close#32129
Instead of destroying and recreating MetadataResolver every time the
program changes, create one instance and reuse it throughout the
lifetime of the language service.
Since Angular StaticSymbols are invalidated when program gets
out-of-date, this should be safe.
This should make the language service more more performant.
PR Close#32145
In VE the `Sanitizer` is always available in `BrowserModule` because the VE retrieves it using injection.
In Ivy the injection is optional and we have instructions instead of component definition arrays. The implication of this is that in Ivy the instructions can pull in the sanitizer only when they are working with a property which is known to be unsafe. Because the Injection is optional this works even if no Sanitizer is present. So in Ivy we first use the sanitizer which is pulled in by the instruction, unless one is available through the `Injector` then we use that one instead.
This PR does few things:
1) It makes `Sanitizer` optional in Ivy.
2) It makes `DomSanitizer` tree shakable.
3) It aligns the semantics of Ivy `Sanitizer` with that of the Ivy sanitization rules.
4) It refactors `DomSanitizer` to use same functions as Ivy sanitization for consistency.
PR Close#31934
This commit creates two concrete classes Inline and External
TemplateSource to differentiate between templates in TS file and
HTML file.
Knowing the template type makes the code much more explicit which
filetype we are dealing with.
With these two classes, there is no need for `getTemplateAt()` method in
TypeScriptHost. Removing this method is safe since it is not used in the
extension. This reduces the API surface of TypescriptHost.
PR Close#32127
Part 3/3 of language-service refactoring:
Change all language service APIs to return TS value since Angular LS
will be a proper tsserver plugin. This reduces the need to transform
results among Angular <--> TS <--> LSP.
PR Close#32116
In Angular today, the following pattern works:
```typescript
export class BaseDir {
constructor(@Inject(ViewContainerRef) protected vcr: ViewContainerRef) {}
}
@Directive({
selector: '[child]',
})
export class ChildDir extends BaseDir {
// constructor inherited from BaseDir
}
```
A decorated child class can inherit a constructor from an undecorated base
class, so long as the base class has metadata of its own (for JIT mode).
This pattern works regardless of metadata in AOT.
In Angular Ivy, this pattern does not work: without the @Directive
annotation identifying the base class as a directive, information about its
constructor parameters will not be captured by the Ivy compiler. This is a
result of Ivy's locality principle, which is the basis behind a number of
compilation optimizations.
As a solution, @Directive() without a selector will be interpreted as a
"directive base class" annotation. Such a directive cannot be declared in an
NgModule, but can be inherited from. To implement this, a few changes are
made to the ngc compiler:
* the error for a selector-less directive is now generated when an NgModule
declaring it is processed, not when the directive itself is processed.
* selector-less directives are not tracked along with other directives in
the compiler, preventing other errors (like their absence in an NgModule)
from being generated from them.
PR Close#31379
Cleanup the logic in TypeScriptHost as to when langauge service state
should be synchronized with the editor state.
The model employed follows that of tsserver, in which case it is the
caller's responsiblity to synchronize host data before any LS methods
are called.
PR Close#32017
For some reason (on OS/X) this transitive dependency is not being passed
through to the final TS builds that rely on this rule, so the build fails
with a missing file error:
```
The specified path does not exist:
'/.../sandbox/darwin-sandbox/451/execroot/angular/packages/tsconfig-build.json'.
```
PR Close#31943
Introduces a new migration schematic that follows the given
migration plan: https://hackmd.io/@alx/S1XKqMZeS.
First case: The schematic detects decorated directives which
inherit a constructor. The migration ensures that all base
classes until the class with the explicit constructor are
properly decorated with "@Directive()" or "@Component". In
case one of these classes is not decorated, the schematic
adds the abstract "@Directive()" decorator automatically.
Second case: The schematic detects undecorated declarations
and copies the inherited "@Directive()", "@Component" or
"@Pipe" decorator to the undecorated derived class. This
involves non-trivial import rewriting, identifier aliasing
and AOT metadata serializing
(as decorators are not always part of source files)
PR Close#31650
The $locationShim has onChange listeners to allow for synchronization logic between
AngularJS and Angular. When the AngularJS routing events are emitted first, this can
cause Angular code to be out of sync. Notifying the listeners earlier solves the
problem.
PR Close#32037
PR #29473 changed the docs to use a string as the input value of `formControlName`, as it used to only accept a string.
This has been changed, and `formControlName` now accepts a string or a number, so the example in the docs can use a binding as they used to.
PR Close#30606
This commit relaxes the type of the `formControlName` input to accept both a `string` and a `number`.
Currently, when using a `FormArray`, most templates look like:
```
<div formArrayName="tags">
<div *ngFor="let tag of tagsArray.controls; index as i">
<input [formControlName]="i">
</div>
</div>
```
Here `formControlName` receives a number whereas its input type is a string.
This is fine for VE and `fullTemplateTypeCheck`, but not for Ivy which does a more thorough type checking on inputs with `fullTemplateTypeCheck` enabled and throws `Type 'number' is not assignable to type 'string'`. It is fixable by using `formControlName="{{i}}"` but you have to know the difference between `a="{{b}}"` and `[a]="b"` and change it all over the application codebase. This commit allows the existing code to still type-check.
PR Close#30606
Follow-up to #30993 where we build all Angular packages with
the TypeScript `--strict` flag. The flag improves overall code
health and also helps us catch issues easier.
PR Close#31967
Part 2/3 of language service refactoring:
Now that the language service is a proper tsserver plugin, all LS
interfaces should return TS values. This PR refactors the
ng.getDiagnostics() API to return ts.Diagnostic[] instead of
ng.Diagnostic[].
PR Close#32115
The language service relies on a "context" file that is used as the
canonical "containing file" when performing module resolution.
This file is unnecessary since the language service host's current
directory always default to the location of tsconfig.json for the
project, which would give the correct result.
This refactoring allows us to simplify the "typescript host" and also
removes the need for custom logic to find tsconfig.json.
PR Close#32015
There has been a regression where enabling rollup treeshaking causes errors during runtime because it will drop const access which will always evaluate to true or false. However, such `const` in `@angular/core` cannot be dropped because their value is changed when NGCC is run on `@angular/core`
VE
```
const SWITCH_IVY_ENABLED__POST_R3__ = true;
const SWITCH_IVY_ENABLED__PRE_R3__ = false;
const ivyEnabled = SWITCH_IVY_ENABLED__PRE_R3__;
```
Ivy (After NGCC)
```
const SWITCH_IVY_ENABLED__POST_R3__ = true;
const SWITCH_IVY_ENABLED__PRE_R3__ = false;
const ivyEnabled = SWITCH_IVY_ENABLED__POST_R3__;
```
FESM2015
```
load(path) {
/** @type {?} */
const legacyOfflineMode = this._compiler instanceof Compiler;
return legacyOfflineMode ? this.loadFactory(path) : this.loadAndCompile(path);
}
```
ESM2015
```
load(path) {
/** @type {?} */
const legacyOfflineMode = !ivyEnabled && this._compiler instanceof Compiler;
return legacyOfflineMode ? this.loadFactory(path) : this.loadAndCompile(path);
}
```
From the above we can see that `ivyEnabled ` is being treeshaken away when generating the FESM bundle which is causing runtime errors such as `Cannot find module './lazy/lazy.module.ngfactory'` since in Ivy we will always load the factories.
PR Close#32069
Similar to interpolation, we do not want to completely remove whitespace
nodes that are siblings of an expansion.
For example, the following template
```html
<div>
<strong>items left<strong> {count, plural, =1 {item} other {items}}
</div>
```
was being collapsed to
```html
<div><strong>items left<strong>{count, plural, =1 {item} other {items}}</div>
```
which results in the text looking like
```
items left4
```
instead it should be collapsed to
```html
<div><strong>items left<strong> {count, plural, =1 {item} other {items}}</div>
```
which results in the text looking like
```
items left 4
```
---
**Analysis of the code and manual testing has shown that this does not cause
the generated ids to change, so there is no breaking change here.**
PR Close#31962
Previously if only a component template changed then we would know to
rebuild its component source file. But the compilation was incorrect if the
component was part of an NgModule, since we were not capturing the
compilation scope information that had a been acquired from the NgModule
and was not being regenerated since we were not needing to recompile
the NgModule.
Now we register compilation scope information for each component, via the
`ComponentScopeRegistry` interface, so that it is available for incremental
compilation.
The `ComponentDecoratorHandler` now reads the compilation scope from a
`ComponentScopeReader` interface which is implemented as a compound
reader composed of the original `LocalModuleScopeRegistry` and the
`IncrementalState`.
Fixes#31654
PR Close#31932
Moves the `renderer_to_renderer2` migration google3 tslint rule
into the new `google3` directory. This is done for consistency
as we recently moved all google3 migration rules into a new
`google3` folder (see: f69e4e6f77).
PR Close#31817
Creates a separate bazel target for the google3 migration
tests. The benefit is that it's faster to run tests for
public migrations in development. Google3 lint rules are
usually another story/implementation and the tests are quite
slow due to how TSLint applies replacements.
Additionally if something changes in the google3 tslint rules,
the tests which aren't affected re-run unnecessarily.
PR Close#31817
In Angular today, the following pattern works:
```typescript
export class BaseDir {
constructor(@Inject(ViewContainerRef) protected vcr: ViewContainerRef) {}
}
@Directive({
selector: '[child]',
})
export class ChildDir extends BaseDir {
// constructor inherited from BaseDir
}
```
A decorated child class can inherit a constructor from an undecorated base
class, so long as the base class has metadata of its own (for JIT mode).
This pattern works regardless of metadata in AOT.
In Angular Ivy, this pattern does not work: without the @Directive
annotation identifying the base class as a directive, information about its
constructor parameters will not be captured by the Ivy compiler. This is a
result of Ivy's locality principle, which is the basis behind a number of
compilation optimizations.
As a solution, @Directive() without a selector will be interpreted as a
"directive base class" annotation. Such a directive cannot be declared in an
NgModule, but can be inherited from. To implement this, a few changes are
made to the ngc compiler:
* the error for a selector-less directive is now generated when an NgModule
declaring it is processed, not when the directive itself is processed.
* selector-less directives are not tracked along with other directives in
the compiler, preventing other errors (like their absence in an NgModule)
from being generated from them.
PR Close#31379