This commit refactors and expands ngtsc's support for generating imports of
values from imports of types (this is used for example when importing a
class referenced in a type annotation in a constructor).
Previously, this logic handled "import {Foo} from" and "import * as foo
from" style imports, but failed on imports of default values ("import
Foo from"). This commit moves the type-to-value logic to a separate file and
expands it to cover the default import case. Doing this also required
augmenting the ImportManager to track default as well as non-default import
generation. The APIs were made a little cleaner at the same time.
PR Close#29146
In the TypeScript compiler API, emit() can be performed either on a single
ts.SourceFile or on the entire ts.Program simultaneously.
ngtsc previously used whole-program emit, which was convenient to use while
spinning up the project but has a significant drawback: it causes a type
checking operation to occur for the whole program, including .d.ts files.
In large Bazel environments (such as Google's codebase), an ngtsc invocation
can have a few .ts files and thousands of .d.ts inputs. This unwanted type
checking is therefore a significant drain on performance.
This commit switches ngtsc to emit each .ts file individually, avoiding the
unwanted type checking.
PR Close#29147
When processing a JavaScript program, TS may come across a symbol that has
been imported from a TypeScript typings file.
In this case the compiler may pass the ReflectionHost a `prototype` symbol
as an export of the class.
This pseudo-member symbol has no declarations, which previously caused the
code in `Esm5ReflectionHost.reflectMembers()` to crash.
Now we just quietly ignore such a symbol and leave `Esm2015ReflectionHost`
to deal with it.
(As it happens `Esm2015ReflectionHost` also quietly ignores this symbol).
PR Close#29158
For the template type checking to work correctly, it needs to know
what attributes are bound to expressions or directives, which may
require expressions in the template to be evaluated in a different
scope.
In inline templates, there are attributes that are now marked as
"Template" attributes. We need to ensure that the template
type checking code looks at these "bound" attributes as well as the
"input" attributes.
PR Close#29041
ngtsc occasionally converts a type reference (such as the type of a
parameter in a constructor) to a value reference (argument to a
directiveInject call). TypeScript has a bad habit of sometimes removing
the import statement associated with this type reference, because it's a
type only import when it initially looks at the file.
A solution to this is to always add an import to refer to a type position
value that's imported, and not rely on the existing import.
PR Close#29111
When ngtsc generates a .ngfactory shim, it does so based on the contents of
an original file in the program. Occasionally these original files have
comments at the top which are load-bearing (e.g. they contain jsdoc
annotations which are significant to downstream bundling tools). The
generated factory shims should preserve this comment.
This commit adds a step to the ngfactory generator to preserve the top-level
comment from the original source file.
FW-1006 #resolve
FW-1095 #resolve
PR Close#29065
The ngtsc partial evaluator previously would not handle an enum reference
inside a template string expression correctly. Enums are resolved to an
`EnumValue` type, which has a `resolved` property with the actual value.
When effectively toString-ing a `ResolvedValue` as part of visiting a
template expression, the partial evaluator needs to translate `EnumValue`s
to their fully resolved value, which this commit does.
PR Close#29062
Currently, ngtsc has a bug where if you alias the name of a decorator when
importing it, it won't be detected properly. This is because the compiler
uses the aliased name and not the original, declared name of the decorator
for detection.
This commit fixes the compiler to compare against the declared name of
decorators when available, and adds a test to prevent regression.
PR Close#29061
ngtsc has cyclic import detection, to determine when adding an import to a
directive or pipe would create a cycle. However, this detection must also
account for already inserted imports, as it's possible for both directions
of a circular import to be inserted by Ivy (as opposed to at least one of
those edges existing in the user's program).
This commit fixes the circular import detection for components to take into
consideration already added edges. This is difficult for one critical
reason: only edges to files which will *actually* be imported should be
considered. However, that depends on which directives & pipes are used in
a given template, which is currently only known by running the
TemplateDefinitionBuilder during the 'compile' phase. This is too late; the
decision whether to use remote scoping (which consults the import graph) is
made during the 'resolve' phase, before any compilation has taken place.
Thus, the only way to correctly consider synthetic edges is for the compiler
to know exactly which directives & pipes are used in a template during
'resolve'. There are two ways to achieve this:
1) refactor `TemplateDefinitionBuilder` to do its work in two phases, with
directive matching occurring as a separate step which can be performed
earlier.
2) use the `R3TargetBinder` in the 'resolve' phase to independently bind the
template and get information about used directives.
Option 1 is ideal, but option 2 is currently used for practical reasons. The
cost of binding the template can be shared with template-typechecking.
PR Close#29040
In the @Component decorator, the 'host' field is an object which represents
host bindings. The type of this field is complex, but is generally of the
form {[key: string]: string}. Several different kinds of bindings can be
specified, depending on the structure of the key.
For example:
```
@Component({
host: {'[prop]': 'someExpr'}
})
```
will bind an expression 'someExpr' to the property 'prop'. This is known to
be a property binding because of the square brackets in the binding key.
If the binding key is a plain string (no brackets or parentheses), then it
is known as an attribute binding. In this case, the right-hand side is not
interpreted as an expression, but is instead a constant string.
There is no actual requirement that at build time, these constant strings
are known to the compiler, but this was previously enforced as a side effect
of requiring the binding expressions for property and event bindings to be
statically known (as they need to be parsed). This commit breaks that
relationship and allows the attribute bindings to be dynamic. In the case
that they are dynamic, the references to the dynamic values are reflected
into the Ivy instructions for attribute bindings.
PR Close#29033
DynamicValues are generated whenever a partially evaluated expression is
unable to be resolved statically. They contain a reference to the ts.Node
which wasn't resolvable.
They can also be nested. For example, the expression 'a + b' is resolvable
only if 'a' and 'b' are themselves resolvable. If either 'a' or 'b' resolve
to a DynamicValue, the whole expression must also resolve to a DynamicValue.
Previously, if 'a' resolved to a DynamicValue, the entire expression might
have been resolved to the same DynamicValue. This correctly indicated that
the expression wasn't resolvable, but didn't return a reference to the
shallow node that couldn't be resolved (the expression 'a + b'), only a
reference to the deep node that couldn't be resolved ('a').
In certain situations, it's very useful to know the shallow unresolvable
node (for example, to use it verbatim in the output). To support this,
the partial evaluator is updated to always wrap DynamicValue to point to
each unresolvable expression as it's processed, ensuring the receiver can
determine exactly which expression node failed to resolve.
PR Close#29033
This change helps highlight certain misoptimizations with Closure
compiler. It is also stylistically preferable to consistently use index
access on index sig types.
Roughly, when one sees '.foo' they know it is always checked for typos
in the prop name by the type system (unless 'any'), while "['foo']" is
always not.
Once all angular repos are conforming this will become a tsetse.info
check, enforced by bazel.
PR Close#28937
Prior to this change, TypeScript stripped out some imports in case we reference a type that can be represented as a value (for ex. classes). This fix ensures that we use correct symbol identifier, which makes TypeScript retain the necessary import statements.
PR Close#28941
Angular supports using <style> and <link> tags inline in component
templates, but previously such tags were not implemented within the ngtsc
compiler. This commit introduces that support.
FW-1069 #resolve
PR Close#28997
This commit introduces support for the windows paths in the new concrete types mechanism that was introduced in this PR https://github.com/angular/angular/pull/28523
Normalized posix paths that start with either a `/` or `C:/` are considered to be an absolute path.
Note: `C:/` is used as a reference, as other drive letters are also supported.
Fixes#28754
PR Close#28752
The partial evaluator in ngtsc can handle a shorthand property declaration
in the middle evaluation, but fails if evaluation starts at the shorthand
property itself. This is because evaluation starts at the ts.Identifier
of the property (the ts.Expression representing it), not the ts.Declaration
for the property.
The fix for this is to detect in TypeScriptReflectionHost when a ts.Symbol
refers to a shorthand property, and to use the ts.TypeChecker method
getShorthandAssignmentValueSymbol() to resolve the value of the assignment
instead.
FW-1089 #resolve
PR Close#28936
In certain configurations (such as the g3 repository) which have lots of
small compilation units as well as strict dependency checking on generated
code, ngtsc's default strategy of directly importing directives/pipes into
components will not work. To handle these cases, an additional mode is
introduced, and is enabled when using the FileToModuleHost provided by such
compilation environments.
In this mode, when ngtsc encounters an NgModule which re-exports another
from a different file, it will re-export all the directives it contains at
the ES2015 level. The exports will have a predictable name based on the
FileToModuleHost. For example, if the host says that a directive Foo is
from the 'root/external/foo' module, ngtsc will add:
```
export {Foo as ɵng$root$external$foo$$Foo} from 'root/external/foo';
```
Consumers of the re-exported directive will then import it via this path
instead of directly from root/external/foo, preserving strict dependency
semantics.
PR Close#28852
This commit splits apart selector_scope.ts in ngtsc and extracts the logic
into two separate classes, the LocalModuleScopeRegistry and the
DtsModuleScopeResolver. The logic is cleaned up significantly and new tests
are added to verify behavior.
LocalModuleScopeRegistry implements the NgModule semantics for compilation
scopes, and handles NgModules declared in the current compilation unit.
DtsModuleScopeResolver implements simpler logic for export scopes and
handles NgModules declared in .d.ts files.
This is done in preparation for the addition of re-export logic to solve
StrictDeps issues.
PR Close#28852
Prior to this change absolute file paths (like `/a/b/c/style.css`) were calculated taking current component file location into account. As a result, absolute file paths were calculated using current file as a root. This change updates this logic to ignore current file path in case of absolute paths.
PR Close#28789
Prior to this change, Ivy and VE CSS resource resolution was different: in addition to specified styleUrl (with .scss, .less and .styl extensions), VE also makes an attempt to resolve resource with .css extension. This change introduces similar logic for Ivy to make sure Ivy behavior is backwards compatible.
PR Close#28770
Prior to this change, the @fileoverview annotations added by users in source files or by tsickle during compilation might have change a location due to the fact that Ngtsc may prepend extra imports or constants. As a result, the output file is considered invalid by Closure (misplaced @fileoverview annotation). In order to resolve the problem we relocate @fileoverview annotation if we detect that its host node shifted.
PR Close#28723
This change is kind of similar to #27466, but instead of ensuring that
these shims can be generated, we also need to make sure that developers
are able to also use the factory shims like with `ngc`.
This issue is now surfacing because we have various old examples which
are now also built with `ngtsc` (due to the bazel migration). On case insensitive
platforms (e.g. windows) these examples cannot be built because ngtsc fails
the app imports a generated shim file (such as the factory shim files).
This is because the `GeneratedShimsHostWrapper` TypeScript host uses
the `getCanonicalFileName` method in order to check whether a given
file/module exists in the generator file maps. e.g.
```
// Generator Map:
'C:/users/paul/_bazel_paul/lm3s4mgv/execroot/angular/packages/core/index.ngfactory.ts' =>
'C:/users/paul/_bazel_paul/lm3s4mgv/execroot/angular/packages/core/index.ts',
// Path passed into `fileExists`
C:/users/paul/_bazel_paul/lm3s4mgv/execroot/angular/packages/core/index.ngfactory.ts
// After getCanonicalFileName (notice the **lower-case drive name**)
c:/users/paul/_bazel_paul/lm3s4mgv/execroot/angular/packages/core/index.ngfactory.ts
```
As seen above, the generator map does not use the canonical file names, as well as
TypeScript internally does not pass around canonical file names. We can fix this by removing
the manual call to `getCanonicalFileName` and just following TypeScript internal-semantics.
PR Close#28831
Fixes a minor typo in the `listLazyRoutes` method for `ngtsc`. Also in
addition fixes that a newly introduced test for `listLazyRoutes` broke the
tests in Windows. It's clear that we still don't run tests against
Windows, but we also made all other tests pass (without CI verification),
and it's not a big deal fixing this while being at it.
PR Close#28831
Prior to this fix, using the compiler's ivy_switch mechanism was
only available to core packages. This patch allows for this variable
switching mechanism to work across all other angular packages.
PR Close#28711
This commit adds support for the `static: true` flag in
`ViewChild` queries. Prior to this commit, all `ViewChild`
queries were resolved after change detection ran. This is
a problem for backwards compatibility because View Engine
also supported "static" queries which would resolve before
change detection.
Now if users add a `static: true` option, the query will be
resolved in creation mode (before change detection runs).
For example:
```ts
@ViewChild(TemplateRef, {static: true}) template !: TemplateRef;
```
This feature will come in handy for components that need
to create components dynamically.
PR Close#28811
Currently if developers use call expressions in their static
class members ([like we do in Angular](https://github.com/angular/angular/blob/master/packages/core/src/change_detection/differs/keyvalue_differs.ts#L121)),
the metadata that is generated for flat modules is invalid. This
is because the metadata bundler logic currently does not handle
call expressions in static class members and the symbol references
are not rewritten to avoid relative paths in the bundle.
Static class members using a call expression are not relevant for
the ViewEngine AOT compilation, but it is problematic that the
bundled metadata references modules using their original relative
path. This means that the bundled metadata is no longer encapsulated
and depends on other emitted files to be emitted in the proper place.
These incorrect relative paths can now cause issues where NGC
looks for the referenced symbols in the incorrect path. e.g.
```
src/
| lib/
| index.ts -> References the call expression using `../../di`
```
Now the metadata looks like that:
```
node_modules/
| @angular/
-- | core/
-- -- | core.metadata.json -> Says that the call expr. is in `../../di`.
| di/
```
Now if NGC tries to use the metadata files and create the summary files,
NGC resolves the call expression to the `node_modules/di` module. Since
the "unexpected" module does not contain the desired symbol, NGC will
error out.
We should fix this by ensuring that we don't ship corrupted metadata
to NPM which contains relative references that can cause such
failures (other imports can be affected as well; it depends on what
modules the developer has installed and how we import our call
expressions).
Fixes#28741.
PR Close#28762
Currently setting `enableIvy` to true runs a hybrid mode of `ngc` and `ngtsc`. This is counterintuitive given the name of the flag itself.
This PR makes the `true` value equivalent to the previous `ngtsc`, and `ngtsc` becomes an alias for `true`. Effectively this removes the hybrid mode as well since there's no other way to enable it.
PR Close#28616
Previously, `ngtsc` detected class inheritance in a way that only worked
in TS or ES2015 code. As a result, inheritance would not be detected for
code in ES5 format, such as when running `ngtsc` through `ngcc` to
transform old-style Angular code to ivy format.
This commit fixes it by delegating class inheritance detection to the
current `ReflectionHost`, which is able to correctly interpret the used
code format.
PR Close#28773
Accounts for schemas in when validating properties in Ivy.
This PR resolves FW-819.
A couple of notes:
* I had to rework the test slightly, in order to have it fail when we expect it to. The one in master is passing since Ivy's validation runs during the update phase, rather than creation.
* I had to deviate from the design in FW-819 and not add an `enableSchema` instruction, because the schema is part of the `NgModule` scope, however the scope is only assigned to a component once all of the module's declarations have been resolved and some of them can be async. Instead, I opted to have the `schemas` on the component definition.
PR Close#28637
The ultimate goal of this commit is to make use of fileNameToModuleName to
get the module specifier to use when generating an import, when that API is
available in the CompilerHost that ngtsc is created with.
As part of getting there, the way in which ngtsc tracks references and
generates import module specifiers is refactored considerably. References
are tracked with the Reference class, and previously ngtsc had several
different kinds of Reference. An AbsoluteReference represented a declaration
which needed to be imported via an absolute module specifier tracked in the
AbsoluteReference, and a RelativeReference represented a declaration from
the local program, imported via relative path or referred to directly by
identifier if possible. Thus, how to refer to a particular declaration was
encoded into the Reference type _at the time of creation of the Reference_.
This commit refactors that logic and reduces Reference to a single class
with no subclasses. A Reference represents a node being referenced, plus
context about how the node was located. This context includes a
"bestGuessOwningModule", the compiler's best guess at which absolute
module specifier has defined this reference. For example, if the compiler
arrives at the declaration of CommonModule via an import to @angular/common,
then any references obtained from CommonModule (e.g. NgIf) will also be
considered to be owned by @angular/common.
A ReferenceEmitter class and accompanying ReferenceEmitStrategy interface
are introduced. To produce an Expression referring to a given Reference'd
node, the ReferenceEmitter consults a sequence of ReferenceEmitStrategy
implementations.
Several different strategies are defined:
- LocalIdentifierStrategy: use local ts.Identifiers if available.
- AbsoluteModuleStrategy: if the Reference has a bestGuessOwningModule,
import the node via an absolute import from that module specifier.
- LogicalProjectStrategy: if the Reference is in the logical project
(is under the project rootDirs), import the node via a relative import.
- FileToModuleStrategy: use a FileToModuleHost to generate the module
specifier by which to import the node.
Depending on the availability of fileNameToModuleName in the CompilerHost,
then, a different collection of these strategies is used for compilation.
PR Close#28523
This commit introduces a new ngtsc sub-library, 'path', which contains
branded string types for the different kind of paths that ngtsc manipulates.
Having static types for these paths will reduce the number of path-related
bugs (especially on Windows) and will eliminate unnecessary defensive
normalizing.
See the README.md file for more detail.
PR Close#28523
Previously, ngtsc would throw an error if two decorators were matched on
the same class simultaneously. However, @Injectable is a special case, and
it appears frequently on component, directive, and pipe classes. For pipes
in particular, it's a common pattern to treat the pipe class also as an
injectable service.
ngtsc actually lacked the capability to compile multiple matching
decorators on a class, so this commit adds support for that. Decorator
handlers (and thus the decorators they match) are classified into three
categories: PRIMARY, SHARED, and WEAK.
PRIMARY handlers compile decorators that cannot coexist with other primary
decorators. The handlers for Component, Directive, Pipe, and NgModule are
marked as PRIMARY. A class may only have one decorator from this group.
SHARED handlers compile decorators that can coexist with others. Injectable
is the only decorator in this category, meaning it's valid to put an
@Injectable decorator on a previously decorated class.
WEAK handlers behave like SHARED, but are dropped if any non-WEAK handler
matches a class. The handler which compiles ngBaseDef is WEAK, since
ngBaseDef is only needed if a class doesn't otherwise have a decorator.
Tests are added to validate that @Injectable can coexist with the other
decorators and that an error is generated when mixing the primaries.
PR Close#28523
In the past, @Injectable had no side effects and existing Angular code is
therefore littered with @Injectable usage on classes which are not intended
to be injected.
A common example is:
@Injectable()
class Foo {
constructor(private notInjectable: string) {}
}
and somewhere else:
providers: [{provide: Foo, useFactory: ...})
Here, there is no need for Foo to be injectable - indeed, it's impossible
for the DI system to create an instance of it, as it has a non-injectable
constructor. The provider configures a factory for the DI system to be
able to create instances of Foo.
Adding @Injectable in Ivy signifies that the class's own constructor, and
not a provider, determines how the class will be created.
This commit adds logic to compile classes which are marked with @Injectable
but are otherwise not injectable, and create an ngInjectableDef field with
a factory function that throws an error. This way, existing code in the wild
continues to compile, but if someone attempts to use the injectable it will
fail with a useful error message.
In the case where strictInjectionParameters is set to true, a compile-time
error is thrown instead of the runtime error, as ngtsc has enough
information to determine when injection couldn't possibly be valid.
PR Close#28523
Translation of WriteKeyExpr expressions was not implemented in the ngtsc
expression translator. This resulted in binding expressions like
"target[key] = $event" not compiling.
This commit fixes the bug by implementing WriteKeyExpr translation.
PR Close#28523
Some applications use enum values in their host bindings:
@Component({
host: {
'[prop]': EnumType.Key,
}, ...
})
This commit changes the resolution of host properties to follow the enum
declaration and extract the correct value for the binding.
PR Close#28523
With #28594 we refactored the `@angular/compiler` slightly to
allow opting out from external symbol re-exports which are
enabled by default.
Since symbol re-exports only benefit projects which have a
very strict dependency enforcement, external symbols should
not be re-exported by default as this could grow the size of
factory files and cause unexpected behavior with Angular's
AOT symbol resolving (e.g. see: #25644).
Note that the common strict dependency enforcement for source
files does still work with external symbol re-exports disabled,
but there are also strict dependency checks that enforce strict
module dependencies also for _generated files_ (such as the
ngfactory files). This is how Google3 manages it's dependencies
and therefore external symbol re-exports need to be enabled within
Google3.
Also "ngtsc" also does not provide any way of using external symbol
re-exports, so this means that with this change, NGC can partially
match the behavior of "ngtsc" then (unless explicitly opted-out).
As mentioned before, internally at Google symbol re-exports need to
be still enabled, so the `ng_module` Bazel rule will enable the symbol
re-exports by default when running within Blaze.
Fixes#25644.
PR Close#28633
During analysis, the `ComponentDecoratorHandler` passes the component
template to the `parseTemplate()` function. Previously, there was little or
no information about the original source file, where the template is found,
passed when calling this function.
Now, we correctly compute the URL of the source of the template, both
for external `templateUrl` and in-line `template` cases. Further in the
in-line template case we compute the character range of the template
in its containing source file; *but only in the case that the template is
a simple string literal*. If the template is actually a dynamic value like
an interpolated string or a function call, then we do not try to add the
originating source file information.
The translator that converts Ivy AST nodes to TypeScript now adds these
template specific source mappings, which account for the file where
the template was found, to the templates to support stepping through the
template creation and update code when debugging an Angular application.
Note that some versions of TypeScript have a bug which means they cannot
support external template source-maps. We check for this via the
`canSourceMapExternalTemplates()` helper function and avoid trying to
add template mappings to external templates if not supported.
PR Close#28055
When tokenizing markup (e.g. HTML) element attributes
can have quoted or unquoted values (e.g. `a=b` or `a="b"`).
The `ATTR_VALUE` tokens were capturing the quotes, which
was inconsistent and also affected source-mapping.
Now the tokenizer captures additional `ATTR_QUOTE` tokens,
which the HTML related parsers understand and factor into their
token parsing.
PR Close#28055
I don't know of any use of this API with a project-root-relative path
(i.e. the cli will always call it with an absolute path), but keeping
the API backwards compatible just in case.
PR Close#28542
This will make it easier to retrieve routes for specific entry points in
`listLazyRoutes()` (which is necessary for CLI integration but not yet
implemented).
PR Close#28542
In https://github.com/angular/angular/pull/27697 the listLazyRoutes was fixed to work with ivy.
Since the entryRoute argument is not supported, it was made to also error.
But by erroring it breaks existing usage with Angular CLI where the entry route is sent in as an argument.
This commit changes listLazyRoutes to not error out, but instead ignore the argument.
PR Close#28372
This lets us run ngtsc under the tsc_wrapped custom compiler (Used in Bazel)
It also allows others to simply wire ngtsc into an existing typescript compilation binary
PR Close#28435
In View Engine, we supported @Input and @ContentChild annotations
on the same property. This feature was somewhat brittle because
it would only work for static queries, so it would break if a
content child was passed in wrapped in an *ngIf. Due to the
inconsistent behavior and low usage both internally and externally,
we will likely be deprecating it in the next version, and it does
not make sense to perpetuate it in Ivy.
This commit ensures that we now throw in Ivy if we encounter the
two annotations on the same property.
PR Close#28415
Prior to this change we may encounter some errors (like pipes being used where they should not be used) while compiling Host Bindings and Listeners. With this update we move validation logic to the analyze phase and throw an error if something is wrong. This also aligns error messages between Ivy and VE.
PR Close#28356
The TypeTranslatorVisitor visitor returned strings because before it wasn't possible to transform declaration files directly through the TypeScript custom transformer API.
Now that's possible though, so it should return nodes instead.
PR Close#28342
The current DtsFileTransformer works by intercepting file writes and editing the source string directly.
This PR refactors it as a afterDeclaration transform in order to fit better in the TypeScript API.
This is part of a greater effort of converting ngtsc to be usable as a TS transform plugin.
PR Close#28342
This lets us run ngtsc under the tsc_wrapped custom compiler (Used in Bazel)
It also allows others to simply wire ngtsc into an existing typescript compilation binary
PR Close#28431
This lets us run ngtsc under the tsc_wrapped custom compiler (Used in Bazel)
It also allows others to simply wire ngtsc into an existing typescript compilation binary
PR Close#27806
In some cases, calling getSourceFile() on a node from within a TS
transform can return undefined (against the signature of the method).
In these cases, getting the original node first will work.
PR Close#28412
By its nature, Ivy alters the import graph of a TS program, adding imports
where template dependencies exist. For example, if ComponentA uses PipeB
in its template, Ivy will insert an import of PipeB into the file in which
ComponentA is declared.
Any insertion of an import into a program has the potential to introduce a
cycle into the import graph. If for some reason the file in which PipeB is
declared imports the file in which ComponentA is declared (maybe it makes
use of a service or utility function that happens to be in the same file as
ComponentA) then this could create an import cycle. This turns out to
happen quite regularly in larger Angular codebases.
TypeScript and the Ivy runtime have no issues with such cycles. However,
other tools are not so accepting. In particular the Closure Compiler is
very anti-cycle.
To mitigate this problem, it's necessary to detect when the insertion of
an import would create a cycle. ngtsc can then use a different strategy,
known as "remote scoping", instead of directly writing a reference from
one component to another. Under remote scoping, a function
'setComponentScope' is called after the declaration of the component's
module, which does not require the addition of new imports.
FW-647 #resolve
PR Close#28169
This commit implements a cycle detector which looks at the import graph of
TypeScript programs and can determine whether the addition of an edge is
sufficient to create a cycle. As part of the implementation, module name
to source file resolution is implemented via a ModuleResolver, using TS
APIs.
PR Close#28169
ngcc's reflection host needs to be able to determine all members of a
class, which it does by using the `ts.Symbol` from TypeScript's
TypeChecker. Such Symbol however may represent multiple class members
in the case of accessors; an equally named getter/setter accessor pair
is combined into a single `ts.Symbol`.
This commit introduces logic to recognize such accessors in order for
both the getter and setter to be considered as class member, similar to
ngtsc's behavior when operating on original TypeScript code.
One difference wrt the TypeScript host is that ngcc cannot see to which
accessor originally had any decorators applied to them, as decorators
are applied to the property descriptor in general, not a specific accessor.
If an accessor has both a setter and getter, any decorators are only
attached to the setter member.
PR Close#28357
Prior to this change, accessor functions for getters and setters would
not be considered as class member, as their declaration is vastly
different from ES2015 syntax.
With this change, the ES5 reflection host has learned to recognize the
downleveled syntax for accessors, allowing for them to be considered as
class member once again.
Fixes#28226
PR Close#28357
This commit uses the NgModuleRouteAnalyzer introduced previously to
implement listLazyRoutes() for NgtscProgram. Currently this implementation
is limited to listing routes globally and cannot list routes for a given lazy
module. Testing seems to indicate that the CLI uses the global form, but this
should be verified.
Jira issue: FW-629
PR Close#27697
This commit introduces a new mode for the NgtscTestEnvironment which
builds the NgtscProgram and then asks for the list of lazy routes,
instead of running the TS emit phase.
PR Close#27697
This commit introduces the NgModuleRouteAnalyzer & friends, which given
metadata about the NgModules in a program can extract the list of lazy
routes in the same format that the ngtools API uses.
PR Close#27697
This commit changes the partial evaluation mechanism to propagate
DynamicValue errors internally during evaluation, and not to "poison"
entire data structures when a single value is dynamic. For example,
previously if any entry in an array was dynamic, evaluating the entire
array would return DynamicValue. Now, the array is returned with only
the specific dynamic entry as DynamicValue.
Instances of DynamicValue also report the node that was determined to
be dynamic, as well as a potential reason for the dynamic-ness. These
can be nested, so an expression `a + b` may have a DynamicValue that
indicates the 'a' term was DynamicValue, which will itself contain a
reason for the dynamic-ness.
This work was undertaken for the implementation of listLazyRoutes(),
which needs to partially evaluate provider arrays, parts of which are
dynamic and parts of which contain useful information.
PR Close#27697
`ngtsc` currently fails building a flat module out file on Windows because it generates an invalid flat module TypeScript source file. e.g:
```ts
5 export * from './C:\Users\Paul\Desktop\test\src\export';
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
This is because `path.posix.relative` does not properly with non-posix paths, and only expects posix paths in order to work.
PR Close#27993
Resources can be loaded in the context of another file, which
means that the path to the resource file must be resolved
before it can be loaded.
Previously the API of this interface did not allow the client
code to get access to the resolved URL which is used to load
the resource.
Now this API has been refactored so that you must do the
resource URL resolving first and the loading expects a
resolved URL.
PR Close#28199
Users might have run the CSS Preprocessor tool *before* the Angular
compiler. For example, we do it that way under Bazel. This means that
the design-time reference is different from the compile-time one - the
input to the Angular compiler is a plain .css file.
We assume that the preprocessor does a trivial 1:1 mapping using the same
basename with a different extension.
PR Close#28166
At the moment, paths stored in `maps` are not normalized and in Windows is causing files not to be found when enabling factory shimming.
For example, the map contents will be
```
Map {
'C:\\git\\cli-repos\\ng-factory-shims\\index.ngfactory.ts' => 'C:\\git\\cli-repos\\ng-factory-shims\\index.ts' }
```
However, ts compiler normalized the paths and is causing;
```
error TS6053: File 'C:/git/cli-repos/ng-factory-shims/index.ngfactory.ts' not found.
error TS6053: File 'C:/git/cli-repos/ng-factory-shims/index.ngsummary.ts' not found.
```
The changes normalized the paths that are stored within the factory and summary maps.
PR Close#28006
This code was throwing if the `deps` array of a provider has several elements, but at the next line it resolves them... With this check `ngtsc` couldn’t compile `ng-bootstrap` for example.
PR Close#28076
ngtsc has a hack to add @nocollapse jsdoc annotations to generated static
fields. This hack is currently broken (likely due to a TypeScript change
in the way writeFile() works).
This commit fixes the hack and introduces an ngtsc_spec test to ensure it
does not regress again.
PR Close#28050
In ESM5 decorated classes can be indicated by calls to `__decorate()`.
Previously the `ReflectionHost.findDecoratedClasses()` call would identify
helper calls of the form:
```
SomeClass = tslib_1.__decorate(...);
```
But it was missing calls of the form:
```
SomeClass = SomeClass_1 = tslib_1.__decorate(...);
```
This form is common in `@NgModule()` decorations, where the class
being decorated is referenced inside the decorator or another
member.
This commit now ensures that a chain of assignments, of any length,
is now identified as a class decoration if it results in a call to
`__decorate()`.
Fixes#27841
PR Close#27848
Prior to this change Component decorator was resolving `encapsulation` value a bit incorrectly, which resulted in `encapsulation: NaN` in compiled code. Now we resolve the value as Enum memeber and throw if it's not the case. As a part of this update, the `changeDetection` field handling is also added, the resolution logic is the same as the one used for `encapsulation` field.
PR Close#27971
exportAs in @Directive metadata supports multiple values, separated by
commas. Previously it was treated as a single value string.
This commit modifies the compiler to understand that exportAs is a
string[]. It stops short of carrying the multiple values through to the
runtime. Instead, it only emits the first one. A future commit will modify
the runtime to accept all the values.
PR Close#28001
Generated factory shims can import from @angular/core. However, we have
special logic in place to rewrite self-imports when generating code for
@angular/core.
This commit leverages the new standalone ImportRewriter interface to
properly rewrite imports in generated factory shims. Before this fix,
a generated factory file for core would look like:
```typescript
import * as i0 from './r3_symbols';
export var ApplicationModuleNgFactory = new ɵNgModuleFactory(...);
```
This is invalid, as ɵNgModuleFactory is just NgModuleFactory when imported
via r3_symbols.
FW-881 #resolve
PR Close#27998
Currently the ImportManager class handles various rewriting actions of
imports when compiling @angular/core. This is required as code compiled
within @angular/core cannot import from '@angular/core'. To work around
this, imports are rewritten to get core symbols from a particular file,
r3_symbols.ts.
In this refactoring, this rewriting logic is moved out of the ImportManager
and put behind an interface, ImportRewriter. There are three implementers
of the interface:
* NoopImportRewriter, used for compiling all non-core packages.
* R3SymbolsImportRewriter, used when ngtsc compiles @angular/core.
* NgccFlatImportRewriter, used when ngcc compiles @angular/core (special
logic is needed because ngcc has to rewrite imports in flat bundles
differently than in non-flat bundles).
This is a precursor to using this rewriting logic in other contexts besides
the ImportManager.
PR Close#27998
A constructor function may have been "synthesized" by TypeScript during
JavaScript emit, in the case no user-defined constructor exists and e.g.
property initializers are used. Those initializers need to be emitted
into a constructor in JavaScript, so the TypeScript compiler generates a
synthetic constructor.
This commit adds identification of such constructors as ngcc needs to be
able to tell if a class did originally have a constructor in the
TypeScript source. When a class has a superclass, a synthesized
constructor must not be considered as a user-defined constructor as that
prevents a base factory call from being created by ngtsc, resulting in a
factory function that does not inject the dependencies of the superclass.
Hence, we identify a default synthesized super call in the constructor
body, according to the structure that TypeScript emits.
PR Close#27897
Previously, ngtsc would assume that a given directive/pipe being imported
from an external package was importable using the same name by which it
was declared. This isn't always true; sometimes a package will export a
directive under a different name. For example, Angular frequently prefixes
directive names with the 'ɵ' character to indicate that they're part of
the package's private API, and not for public consumption.
This commit introduces the TsReferenceResolver class which, given a
declaration to import and a module name to import it from, can determine
the exported name of the declared class within the module. This allows
ngtsc to pick the correct name by which to import the class instead of
making assumptions about how it was exported.
This resolver is used to select a correct symbol name when creating an
AbsoluteReference.
FW-517 #resolve
FW-536 #resolve
PR Close#27743
This commit adds tracking of modules, directives, and pipes which are made
visible to consumers through NgModules exported from the package entrypoint.
ngtsc will now produce a diagnostic if such classes are not themselves
exported via the entrypoint (as this is a requirement for downstream
consumers to use them with Ivy).
To accomplish this, a graph of references is created and populated via the
ReferencesRegistry. Symbols exported via the package entrypoint are compared
against the graph to determine if any publicly visible symbols are not
properly exported. Diagnostics are produced for each one which also show the
path by which they become visible.
This commit also introduces a diagnostic (instead of a hard compiler crash)
if an entrypoint file cannot be correctly determined.
PR Close#27743
Upcoming work to implement import resolution will change the dependencies
of some higher-level classes in ngtsc & ngcc. This necessitates changes in
how these classes are created and the lifecycle of the ts.Program in ngtsc
& ngcc.
To avoid complicating the implementation work with refactoring as a result
of the new dependencies, the refactoring is performed in this commit as a
separate prepatory step.
In ngtsc, the testing harness is modified to allow easier access to some
aspects of the ts.Program.
In ngcc, the main change is that the DecorationAnalyzer is created with the
ts.Program as a constructor parameter. This is not a lifecycle change, as
it was previously created with the ts.TypeChecker which is derived from the
ts.Program anyways. This change requires some reorganization in ngcc to
accommodate, especially in testing harnesses where DecorationAnalyzer is
created manually in a number of specs.
PR Close#27743
This refactoring moves code around between a few of the ngtsc subpackages,
with the goal of having a more logical package structure. Additional
interfaces are also introduced where they make sense.
The 'metadata' package formerly contained both the partial evaluator,
the TypeScriptReflectionHost as well as some other reflection functions,
and the Reference interface and various implementations. This package
was split into 3 parts.
The partial evaluator now has its own package 'partial_evaluator', and
exists behind an interface PartialEvaluator instead of a top-level
function. In the future this will be useful for reducing churn as the
partial evaluator becomes more complicated.
The TypeScriptReflectionHost and other miscellaneous functions have moved
into a new 'reflection' package. The former 'host' package which contained
the ReflectionHost interface and associated types was also merged into this
new 'reflection' package.
Finally, the Reference APIs were moved to the 'imports' package, which will
consolidate all import-related logic in ngtsc.
PR Close#27743
This commit moves the FlatIndexGenerator to its own package, in preparation
to expand its capabilities and support re-exporting of private declarations
from NgModules.
PR Close#27743
Normally functions that return `ModuleWithProvider` objects should parameterize
the return type to include the type of `NgModule` that is being returned. For
example `forRoot(): ModuleWithProviders<RouterModule>`.
But in some cases, especially those generated by nccc, these functions to not
explicitly declare `ModuleWithProviders` as their return type. Instead they
return a "intersection" type, one of whose members is a type literal that
declares the `NgModule` type returned. For example:
`forRoot(): CustomType&{ngModule:RouterModule}`.
This commit changes the `NgModuleDecoratorHandler` so that it can extract
the `NgModule` type from either kind of declaration.
PR Close#27326
Exported functions or static method that return a `ModuleWithProviders`
compatible structure need to provide information about the referenced
`NgModule` type in their return type.
This allows ngtsc to be able to understand the type of `NgModule` that is
being returned from calls to the function, without having to dig into the
internals of the compiled library.
There are two ways to provide this information:
* Add a type parameter to the `ModuleWithProviders` return type. E.g.
```
static forRoot(): ModuleWithProviders<SomeNgModule>;
```
* Convert the return type to a union that includes a literal type. E.g.
```
static forRoot(): (SomeOtherType)&{ngModule:SomeNgModule};
```
This commit updates the rendering of typings files to include this type
information on all matching functions/methods.
PR Close#27326
To support updating `ModuleWithProviders` calls,
we need to be able to map exported functions between
source and typings files, as well as classes.
PR Close#27326
Typescript 3.2 introduced BigInt type, and consequently the
implementation for checkExpressionWorker() in checkers.ts is refactored.
For NumberLiteral and StringLiteral types, 'text' filed must be present
in the Node type, therefore they must be LiteralLikeNode instead of
Node.
PR Close#27536
With the bundle info being assembled into a single object before the
transform is started, we now greedily create a TypeScript program up-front.
If a marker file exists that indicates that the bundle could be skipped
the program creation has already taken place which takes a significant
amount of time. This commit moves the marker check to occur before the
bundle is assembled.
PR Close#27438
ngcc would feed ngtsc with the function declaration inside of an IIFE as
that is considered the class symbol's declaration node, according to
TypeScript's `ts.Symbol.valueDeclaration`. ngtsc however only considered
variable decls and actual class decls as potential class declarations,
so given the function declaration node it would fail to generate the
`setClassMetadata` call.
ngtsc no longer makes its own assumptions about what classes look like,
but always asks the reflection host to yield this kind of information.
PR Close#27438
A surprising interaction with the MagicString library caused inserted
Ivy definitions to be dropped during the removal of decorators, iff all
decorators on the class could be removed. In that case, the removal
location corresponds with the exact location where Ivy definitions were
inserted into.
This commit moves the removal of decorators to occur before Ivy
definitions are inserted. This effectively avoids the problem, as later
inserted text fragments will be retained by MagicString.
PR Close#27159
If a template contains specific TypeScript syntax, such as a non-null
assertion, the code that is emitted from ngcc into a JavaScript bundle
should not retain such syntax as it is invalid in JS.
A full-blown TypeScript emit of a complete ts.SourceFile would be
required to be able to emit JS and possibly downlevel into a lower
language target, which is not an option for ngcc as it currently
operates on partial ASTs, not full source files.
Instead, ngtsc no longer produces TypeScript specific syntax in the first
place, such that TypeScript print logic will only generate JS code.
PR Close#27051
In Ivy, a pure call to `setClassMetadata` is inserted to retain the
information that would otherwise be lost while eliding the Angular
decorators. In the past, the Angular constructor decorators were
wrapped inside of an anonymous function which was only evaluated once
`ReflectionCapabilities` was requested for such metadata. This approach
prevents forward references from inside the constructor parameter
decorators from being evaluated before they are available.
In the `setClassMetadata` call, the constructor parameters were not wrapped
within an anonymous function, such that forward references were evaluated
too early, causing runtime errors.
This commit changes the `setClassMetadata` call to pass the constructor
parameter decorators inside of an anonymous function again, such that
forward references are not resolved until requested by
`ReflectionCapabilities`, therefore avoiding the early reads of forward refs.
PR Close#27561
With ngcc's ability to fixup pre-Ivy ModuleWithProviders such that they
include a reference to the NgModule type, the type may become a qualified
name:
```
import {ModuleWithProviders} from '@angular/core';
import * as ngcc0 from './module';
export declare provide(): ModuleWithProviders<ngcc0.Module>;
```
ngtsc now takes this situation into account when reflecting a
ModuleWithProvider's type argument.
PR Close#27562
Previously, ngtsc did not respect the angularCompilerOptions settings
for generating flat module indices. This commit adds a
FlatIndexGenerator which is used to implement those options.
FW-738 #resolve
PR Close#27497
Previously the ngtsc ShimGenerator interface expected that all shims would
be generated using the contents of existing ts.SourceFiles. This assumption
was true for ngfactory and ngsummary files, but breaks down for flat module
index files, which are standalone.
This commit prepares for flat module index generation by enabling shim
generators which don't require an existing file.
PR Close#27497
Analogously to directives, the `ngInjectableDef` field in .d.ts files is
annotated with the type of service that it represents. If the service
contains required generic type arguments, these must be included in
the .d.ts file.
PR Close#27037
Common insensitive platforms are `win32/win64` (see:
[here](3e4c5c95ab/src/compiler/sys.ts (L681-L682)))
Currently when running `bazel build packages/core --define=compile=aot`, the `compiler-cli` will throw because it cannot find the `index.ngfactory.ts` file in the compiler host. This is because the shim host wrapper is not properly generating the requested `ngfactory` file.
This happens because we call `getCanonicalFileName` that returns a path that is different to the actual program filenames that are used to construct a map of generated files. Since the generators always use the paths which are not "canonical" and pases them internally like that, we can just stop manually calling `getCanonicalFileName`.
PR Close#27466
ngfactory files have a ɵNonEmptyModule constant included if there are no
other exported factory symbols. Previously this extra export was added
dynamically in a TS transformer.
However, synthetically constructed exports don't get properly downleveled
during JS emit, and this generated constant caused issues with downstream
tests.
Instead, this commit configures the shim to always have this export to
begin with, and to filter it out if it's not required.
Testing strategy: covered by existing ngtsc_spec tests which verify the
presence of the ɵNonEmptyModule symbol.
PR Close#27483
In ngtsc, files loaded into the ts.Program have a "module name", set via
ts.SourceFile.moduleName, which ends up being written into an AMD module
name triple-slash directive in the generated .js file.
For generated shim files (ngfactories, ngsummaries) that are constructed
synthetically, there was previously no moduleName set, which caused some
issues with downstream tests.
This commit adds logic to compute and set moduleNames for both generated
ngfactory and ngsummary shims.
PR Close#27483
A previous fix to ngtsc opened the door for duplicate directives in
the 'directives' array of a component. This would happen if the directive
was declared in a module which was imported more than once within the
component's module.
This commit adds deduplication when the component's scope is materialized,
so declarations which arrive via more than one module import are coalesced.
PR Close#27462
The method `ts.CompilerHost.directoryExists` is optional, and was not
previously handled by our ts.CompilerHost wrapper for factory and
summary shims (GeneratedShimsHostWrapper).
TypeScript checks for the existence of this method and silently ignores
things like typeRoots if it's not found. This commit adds proper handling
of directoryExists() to the shim.
A test is also added which verifies typeRoots behavior works when shims
are enabled.
PR Close#27470
Previously the ngfactory shim generator in ngtsc would always write two
imports in the factory file shims:
1) an import to @angular/core
2) an import to the base file
If the base file has no exports, import #2 would be empty. This turns out
to cause issues downstream.
This commit changes the generated shim so if there are no exports in the
base file, the generated shim is empty too.
PR Close#27470
Previously ngtsc assumed resource files (templateUrl, styleUrls) would be
physically present in the file system relative to the .ts file which
referenced them. However, ngc previously resolved such references in the
context of ts.CompilerOptions.rootDirs. Material depends on this
functionality in its build.
This commit introduces resolution of resources by leveraging the TypeScript
module resolver, ts.resolveModuleName(). This resolver is used in a way
which will never succeed, but on failure will return a list of locations
checked. This list is then filtered to obtain the correct potential
locations of the resource.
PR Close#27357
This commit adds support for resolution of styleUrls to ngtsc. Previously
this field was never read, and so components with styleUrls would appear
unstyled after compilation.
PR Close#27357
When a single resource is preloaded twice in ngtsc, the second request
would be recognized as in-flight in which case `undefined` would
be returned, which signals to the compilation that is can resume
synchronously. The compilation would then proceed immediately and call
`load`, only to find out that the request is still in-flight which is
not allowed.
This commit caches the Promise of the in-flight fetch requests, such
that subsequent preload requests can return the corresponding Promise
instance.
PR Close#27357
* Currently when building a `ng_module` with Bazel and having the flat module id option set, the flat module files are not being generated because `@angular/compiler-cli` does not properly determine the entry-point file.
Note that this logic is not necessarily specific to Bazel and the same problem can happen without Bazel if multiple TypeScript input files are specified while the `flatModuleIndex` option has been enabled.
PR Close#27200
For ngcc's processing of ES5 bundles, the spread syntax has been
downleveled from `[...ARRAY]` to become `ARRAY.slice()`. This commit
adds basic support for static resolution of such call.
PR Close#27158
Ngcc will now render additional exports for classes that are referenced in
`NgModule` decorated classes, but which were not publicly exported
from an entry-point of the package.
This is important because when ngtsc compiles libraries processed by ngcc
it needs to be able to publcly access decorated classes that are referenced
by `NgModule` decorated classes in order to build templates that use these
classes.
Doing this re-exporting is not without its risks. There are chances that
the class is not exported correctly: there may already be similarly named
exports from the entry-point or the class may be being aliased. But there
is not much more we can do from the point of view of ngcc to workaround
such scenarios. Generally, packages should have been built so that this
approach works.
PR Close#26906
There are a number of variables that need to be passed around
the program, in particular to the renderers, which benefit from being
stored in well defined objects.
The new `EntryPointBundle` structure is a specific format of an entry-point
and contains the compiled `BundleProgram` objects for the source and typings,
if appropriate.
This change helps with future refactoring, where we may need to add new
properties to this object. It allows us to maintain more stable APIs between
the constituent parts of ngcc, rather than passing lots of primitive values
around throughout the program.
PR Close#26906
The `NgModuleDecoratorHandler` can now register all the references that
it finds in the `NgModule` metadata, such as `declarations`, `imports`,
`exports` etc.
This information can then be used by ngcc to work out if any of these
references are internal only and need to be manually exported from a
library's entry-point.
PR Close#26906
By inverting the relationship between `EntryPointPaths` and
`EntryPointFormat` we can have interfaces rather than types.
Thanks to @gkalpak for this idea.
PR Close#26906
If a decorated class is not publicly exported via an entry-point then the
previous approach to finding the associated typings file failed.
Now we ensure that we extract all the class declarations from the
dtsTypings program, even if they are not exported from the entry-point.
This is achieved by also parsing statements of each source file, rather
than just parsing classes that are exported from the entry-point.
Because we now look at all the files, it is possible for there to be multiple
class declarations with the same local name. In this case, only the first
declaration with a given name is added to the map; subsequent classes are
ignored.
We are most interested in classes that are publicly exported from the
entry-point, so these are added to the map first, to ensure that they are
not ignored.
PR Close#26906
Previously the concept of multiple directives with the same selector was
not supported by ngtsc. This is due to the treatment of directives for a
component as a Map from selector to the directive, which is an erroneous
representation.
Now the directives for a component are stored as an array which supports
multiple directives with the same selector.
Testing strategy: a new ngtsc_spec test asserts that multiple directives
with the same selector are matched on an element.
PR Close#27298
When ngtsc compiles @angular/core, it rewrites core imports to the
r3_symbols.ts file that exposes all internal symbols under their
external name. When creating the FESM bundle, the r3_symbols.ts file
causes the external symbol names to be rewritten to their internal name.
Under ngcc compilations of FESM bundles, the indirection of
r3_symbols.ts is no longer in place such that the external names are
retained in the bundle. Previously, the external name `ɵdefineNgModule`
was explicitly declared internally to resolve this issue, but the
recently added `setClassMetadata` was not declared as such, causing
runtime errors.
Instead of relying on the r3_symbols.ts file to perform the rewrite of
the external modules to their internal variants, the translation is
moved into the `ImportManager` during the compilation itself. This
avoids the need for providing the external name manually.
PR Close#27055
Now that the Ivy switch transform uses ts.getMutableClone() to copy
statements, there's no need to set .parent pointers on the resulting
updated nodes. Doing this was causing assertion failures deep in
TypeScript in some cases.
PR Close#27170
Make a copy of the ts.SourceFile before modifying it in the ivy_switch
transform. It's suspected that the Bazel tsc_wrapped host's SourceFile
cache has issues when the ts.SourceFiles are mutated.
PR Close#27032
In a more specific scenario: Considering people use a custom TypeScript compiler host with `NGC`, they _could_ expect only posix paths in methods like `writeFile`. This at first glance sounds like a trivial issue that should be just fixed by the actual compiler host, but usually TypeScript internal API's just pass around posix normalized paths, and therefore it would be good to follow the same standards when passing JSON genfiles to the `CompilerHost`.
For normal TypeScript files (and TS genfiles), this is already consistent because those will be handled by the actual TypeScript `Program` (see `emitCallback`).
PR Close#27062
This fixes an issue where packages would be skipped if they contained
e.g. RxJS 5 style imports such as
```
import { observeOn } from 'rxjs/operators/observeOn';
```
Given that no package.json file can be found at the imported path, the
dependency would be reported missing, causing the package to be skipped.
PR Close#27031