We recently added a transformer to NGC that is responsible for downleveling Angular
decorators and constructor parameter types. The primary goal was to mitigate a
TypeScript limitation/issue that surfaces in Angular projects due to the heavy
reliance on type metadata being captured for DI. Additionally this is a pre-requisite
of making `tsickle` optional in the Angular bazel toolchain.
See: 401ef71ae5b01be95d124184a0b6936fc453a5d4 for more context on this.
Another (less important) goal was to make sure that the CLI can re-use
this transformer for its JIT mode compilation. The CLI (as outlined in
the commit mentioned above), already has a transformer for downleveling
constructor parameters. We want to avoid this duplication and exported
the transform through the tooling-private compiler entry-point.
Early experiments in using this transformer over the current one, highlighted
that in JIT, class decorators cannot be downleveled. Angular relies on those
to be invoked immediately for JIT (so that factories etc. are generated upon loading)
The transformer we exposed, always downlevels such class decorators
though, so that would break CLI's JIT mode. We can address the CLI's
needs by adding another flag to skip class decorators. This will allow
us to continue with the goal of de-duplication.
PR Close#37545
In v7 of Angular we removed `tsickle` from the default `ngc` pipeline.
This had the negative potential of breaking ES2015 output and SSR due
to a limitation in TypeScript.
TypeScript by default preserves type information for decorated constructor
parameters when `emitDecoratorMetadata` is enabled. For example,
consider this snippet below:
```
@Directive()
export class MyDirective {
constructor(button: MyButton) {}
}
export class MyButton {}
```
TypeScript would generate metadata for the `MyDirective` class it has
a decorator applied. This metadata would be needed in JIT mode, or
for libraries that provide `MyDirective` through NPM. The metadata would
look as followed:
```
let MyDirective = class MyDir {}
MyDirective = __decorate([
Directive(),
__metadata("design:paramtypes", [MyButton]),
], MyDirective);
let MyButton = class MyButton {}
```
Notice that TypeScript generated calls to `__decorate` and
`__metadata`. These calls are needed so that the Angular compiler
is able to determine whether `MyDirective` is actually an directive,
and what types are needed for dependency injection.
The limitation surfaces in this concrete example because `MyButton`
is declared after the `__metadata(..)` call, while `__metadata`
actually directly references `MyButton`. This is illegal though because
`MyButton` has not been declared at this point. This is due to the
so-called temporal dead zone in JavaScript. Errors like followed will
be reported at runtime when such file/code evaluates:
```
Uncaught ReferenceError: Cannot access 'MyButton' before initialization
```
As noted, this is a TypeScript limitation because ideally TypeScript
shouldn't evaluate `__metadata`/reference `MyButton` immediately.
Instead, it should defer the reference until `MyButton` is actually
declared. This limitation will not be fixed by the TypeScript team
though because it's a limitation as per current design and they will
only revisit this once the tc39 decorator proposal is finalized
(currently stage-2 at time of writing).
Given this wontfix on the TypeScript side, and our heavy reliance on
this metadata in libraries (and for JIT mode), we intend to fix this
from within the Angular compiler by downleveling decorators to static
properties that don't need to evaluate directly. For example:
```
MyDirective.ctorParameters = () => [MyButton];
```
With this snippet above, `MyButton` is not referenced directly. Only
lazily when the Angular runtime needs it. This mitigates the temporal
dead zone issue caused by a limitation in TypeScript's decorator
metadata output. See: https://github.com/microsoft/TypeScript/issues/27519.
In the past (as noted; before version 7), the Angular compiler by
default used tsickle that already performed this transformation. We
moved the transformation to the CLI for JIT and `ng-packager`, but now
we realize that we can move this all to a single place in the compiler
so that standalone ngc consumers can benefit too, and that we can
disable tsickle in our Bazel `ngc-wrapped` pipeline (that currently
still relies on tsickle to perform this decorator processing).
This transformation also has another positive side-effect of making
Angular application/library code more compatible with server-side
rendering. In principle, TypeScript would also preserve type information
for decorated class members (similar to how it did that for constructor
parameters) at runtime. This becomes an issue when your application
relies on native DOM globals for decorated class member types. e.g.
```
@Input() panelElement: HTMLElement;
```
Your application code would then reference `HTMLElement` directly
whenever the source file is loaded in NodeJS for SSR. `HTMLElement`
does not exist on the server though, so that will become an invalid
reference. One could work around this by providing global mocks for
these DOM symbols, but that doesn't match up with other places where
dependency injection is used for mocking DOM/browser specific symbols.
More context in this issue: #30586. The TL;DR here is that the Angular
compiler does not care about types for these class members, so it won't
ever reference `HTMLElement` at runtime.
Fixes#30106. Fixes#30586. Fixes#30141.
Resolves FW-2196. Resolves FW-2199.
PR Close#37382
In Ivy, Angular decorators are compiled into static fields that are
inserted into a class declaration in a TypeScript transform. When
targeting Closure compiler such fields need to be annotated with
`@nocollapse` to prevent them from being lifted from a static field into
a variable, as that would prevent the Ivy runtime from being able to
find the compiled definitions.
Previously, there was a bug in TypeScript where synthetic comments added
in a transform would not be emitted at all, so as a workaround a global
regex-replace was done in the emit's `writeFile` callback that would add
the `@nocollapse` annotation to all static Ivy definition fields. This
approach is no longer possible when ngtsc is running as TypeScript
plugin, as a plugin cannot control emit behavior.
The workaround is no longer necessary, as synthetic comments are now
properly emitted, likely as of
https://github.com/microsoft/TypeScript/pull/22141 which has been
released with TypeScript 2.8.
This change is required for running ngtsc as TypeScript plugin in
Bazel's `ts_library` rule, to move away from the custom `ngc_wrapped`
approach.
Resolves FW-1952
PR Close#35932
This commit adds support in the Angular monorepo and in the Angular
compiler(s) for TypeScript 3.8. All packages can now compile with
TS 3.8.
For most of the repo, only a handful few typings adjustments were needed:
* TS 3.8 has a new `CustomElementConstructor` DOM type, which enforces a
zero-argument constructor. The `NgElementConstructor` type previously
declared a required `injector` argument despite the fact that its
implementation allowed `injector` to be optional. The interface type was
updated to reflect the optionality of the argument.
* Certain error messages were changed, and expectations in tests were
updated as a result.
* tsserver (part of language server) now returns performance information in
responses, so test expectations were changed to only assert on the actual
body content of responses.
For compiler-cli and schematics (which use the TypeScript AST) a major
breaking change was the introduction of the export form:
```typescript
export * as foo from 'bar';
```
This is a `ts.NamespaceExport`, and the `exportClause` of a
`ts.ExportDeclaration` can now take this type as well as `ts.NamedExports`.
This broke a lot of places where `exportClause` was assumed to be
`ts.NamedExports`.
For the most part these breakages were in cases where it is not necessary
to handle the new `ts.NamedExports` anyway. ngtsc's design uses the
`ts.TypeChecker` APIs to understand syntax and so automatically supports the
new form of exports.
The View Engine compiler on the other hand extracts TS structures into
metadata.json files, and that format was not designed for namespaced
exports. As a result it will take a nontrivial amount of work if we want to
support such exports in View Engine. For now, these new exports are not
accounted for in metadata.json, and so using them in "folded" Angular
expressions will result in errors (probably claiming that the referenced
exported namespace doesn't exist).
Care was taken to only use TS APIs which are present in 3.7/3.6, as Angular
needs to remain compatible with these for the time being.
This commit does not update angular.io.
PR Close#35864
Previously, NgtscProgram lived in the main @angular/compiler-cli package
alongside the legacy View Engine compiler. As a result, the main package
depended on all of the ngtsc internal packages, and a significant portion of
ngtsc logic lived in NgtscProgram.
This commit refactors NgtscProgram and moves the main logic of compilation
into a new 'core' package. The new package defines a new API which enables
implementers of TypeScript compilers (compilers built using the TS API) to
support Angular transpilation as well. It involves a new NgCompiler type
which takes a ts.Program and performs Angular analysis and transformations,
as well as an NgCompilerHost which wraps an input ts.CompilerHost and adds
any extra Angular files.
Together, these two classes are used to implement a new NgtscProgram which
adapts the legacy api.Program interface used by the View Engine compiler
onto operations on the new types. The new NgtscProgram implementation is
significantly smaller and easier to reason about.
The new NgCompilerHost replaces the previous GeneratedShimsHostWrapper which
lived in the 'shims' package.
A new 'resource' package is added to support the HostResourceLoader which
previously lived in the outer compiler package.
As a result of the refactoring, the dependencies of the outer
@angular/compiler-cli package on ngtsc internal packages are significantly
trimmed.
This refactoring was driven by the desire to build a plugin interface to the
compiler so that tsc_wrapped (another consumer of the TS compiler APIs) can
perform Angular transpilation on user request.
PR Close#34887
Previously, the template type-checker would always construct a generic
template context type with correct bounds, even when strictTemplates was
disabled. This meant that type-checking of expressions involving that type
was stricter than View Engine.
This commit introduces a 'strictContextGenerics' flag which behaves
similarly to other 'strictTemplates' flags, and switches the inference of
generic type parameters on the component context based on the value of this
flag.
PR Close#34649
It is now an error if '"fullTemplateTypeCheck"' is disabled while
`"strictTemplates"` is enabled, as enabling the latter implies that the
former is also enabled.
PR Close#34195
Now that `@angular/localize` can interpret multiple legacy message ids in the
metablock of a `$localize` tagged template string, this commit adds those
ids to each i18n message extracted from component templates, but only if
the `enableI18nLegacyMessageIdFormat` is not `false`.
PR Close#34135
In ViewEngine we were only generating code for exported classes, however with Ivy we do it no matter whether the class has been exported or not. These changes add an extra flag that allows consumers to opt into the ViewEngine behavior. The flag works by treating non-exported classes as if they're set to `jit: true`.
Fixes#33724.
PR Close#33921
Removes `ngBaseDef` from the compiler and any runtime code that was still referring to it. In the cases where we'd previously generate a base def we now generate a definition for an abstract directive.
PR Close#33264
For abstract directives, i.e. directives without a selector, it may
happen that their constructor is called explicitly from a subclass,
hence its parameters are not required to be valid for Angular's DI
purposes. Prior to this commit however, having an abstract directive
with a constructor that has parameters that are not eligible for
Angular's DI would produce a compilation error.
A similar scenario may occur for `@Injectable`s, where an explicit
`use*` definition allows for the constructor to be irrelevant. For
example, the situation where `useFactory` is specified allows for the
constructor to be called explicitly with any value, so its constructor
parameters are not required to be valid. For `@Injectable`s this is
handled by generating a DI factory function that throws.
This commit implements the same solution for abstract directives, such
that a compilation error is avoided while still producing an error at
runtime if the type is instantiated implicitly by Angular's DI
mechanism.
Fixes#32981
PR Close#32987
The template type checking abilities of the Ivy compiler are far more
advanced than the level of template type checking that was previously
done for Angular templates. Up until now, a single compiler option
called "fullTemplateTypeCheck" was available to configure the level
of template type checking. However, now that more advanced type checking
is being done, new errors may surface that were previously not reported,
in which case it may not be feasible to fix all new errors at once.
Having only a single option to disable a large number of template type
checking capabilities does not allow for incrementally addressing newly
reported types of errors. As a solution, this commit introduces some new
compiler options to be able to enable/disable certain kinds of template
type checks on a fine-grained basis.
PR Close#33365
During the creation of an Angular program in the compiler, a check is
done to verify whether the version of TypeScript is considered
supported, producing an error if it is not. This check was missing in
the Ivy compiler, so users may have ended up running an unsupported
TypeScript version inadvertently.
Resolves FW-1643
PR Close#33377
This commit refactors the aliasing system to support multiple different
AliasingHost implementations, which control specific aliasing behavior
in ngtsc (see the README.md).
A new host is introduced, the `PrivateExportAliasingHost`. This solves a
longstanding problem in ngtsc regarding support for "monorepo" style private
libraries. These are libraries which are compiled separately from the main
application, and depended upon through TypeScript path mappings. Such
libraries are frequently not in the Angular Package Format and do not have
entrypoints, but rather make use of deep import style module specifiers.
This can cause issues with ngtsc's ability to import a directive given the
module specifier of its NgModule.
For example, if the application uses a directive `Foo` from such a library
`foo`, the user might write:
```typescript
import {FooModule} from 'foo/module';
```
In this case, foo/module.d.ts is path-mapped into the program. Ordinarily
the compiler would see this as an absolute module specifier, and assume that
the `Foo` directive can be imported from the same specifier. For such non-
APF libraries, this assumption fails. Really `Foo` should be imported from
the file which declares it, but there are two problems with this:
1. The compiler would have to reverse the path mapping in order to determine
a path-mapped path to the file (maybe foo/dir.d.ts).
2. There is no guarantee that the file containing the directive is path-
mapped in the program at all.
The compiler would effectively have to "guess" 'foo/dir' as a module
specifier, which may or may not be accurate depending on how the library and
path mapping are set up.
It's strongly desirable that the compiler not break its current invariant
that the module specifier given by the user for the NgModule is always the
module specifier from which directives/pipes are imported. Thus, for any
given NgModule from a particular module specifier, it must always be
possible to import any directives/pipes from the same specifier, no matter
how it's packaged.
To make this possible, when compiling a file containing an NgModule, ngtsc
will automatically add re-exports for any directives/pipes not yet exported
by the user, with a name of the form: ɵngExportɵModuleNameɵDirectiveName
This has several effects:
1. It guarantees anyone depending on the NgModule will be able to import its
directives/pipes from the same specifier.
2. It maintains a stable name for the exported symbol that is safe to depend
on from code on NPM. Effectively, this private exported name will be a
part of the package's .d.ts API, and cannot be changed in a non-breaking
fashion.
Fixes#29361
FW-1610 #resolve
PR Close#33177
As a hack to get the Ivy compiler ngtsc off the ground, the existing
'allowEmptyCodegenFiles' option was used to control generation of ngfactory
and ngsummary shims during compilation. This option was selected since it's
enabled in google3 but never enabled in external projects.
As ngtsc is now mature and the role shims play in compilation is now better
understood across the ecosystem, this commit introduces two new compiler
options to control shim generation:
* generateNgFactoryShims controls the generation of .ngfactory shims.
* generateNgSummaryShims controls the generation of .ngsummary shims.
The 'allowEmptyCodegenFiles' option is still honored if either of the above
flags are not set explicitly.
PR Close#33256
Injectable defs are not considered public API, so the property
that contains them should be prefixed with Angular's marker
for "private" ('ɵ') to discourage apps from relying on def
APIs directly.
This commit adds the prefix and shortens the name from
ngInjectableDef to "prov" (for "provider", since injector defs
are known as "inj"). This is because property names cannot
be minified by Uglify without turning on property mangling
(which most apps have turned off) and are thus size-sensitive.
PR Close#33151
Injector defs are not considered public API, so the property
that contains them should be prefixed with Angular's marker
for "private" ('ɵ') to discourage apps from relying on def
APIs directly.
This commit adds the prefix and shortens the name from
ngInjectorDef to inj. This is because property names
cannot be minified by Uglify without turning on property
mangling (which most apps have turned off) and are thus
size-sensitive.
PR Close#33151
Module defs are not considered public API, so the property
that contains them should be prefixed with Angular's marker
for "private" ('ɵ') to discourage apps from relying on def
APIs directly.
This commit adds the prefix and shortens the name from
ngModuleDef to mod. This is because property names
cannot be minified by Uglify without turning on property
mangling (which most apps have turned off) and are thus
size-sensitive.
PR Close#33142
Pipe defs are not considered public API, so the property
that contains them should be prefixed with Angular's marker
for "private" ('ɵ') to discourage apps from relying on def
APIs directly.
This commit adds the prefix and shortens the name from
ngPipeDef to pipe. This is because property names
cannot be minified by Uglify without turning on property
mangling (which most apps have turned off) and are thus
size-sensitive.
PR Close#33142
Factory defs are not considered public API, so the property
that contains them should be prefixed with Angular's marker
for "private" ('ɵ') to discourage apps from relying on def
APIs directly.
This commit adds the prefix and shortens the name from
ngFactoryDef to fac. This is because property names
cannot be minified by Uglify without turning on property
mangling (which most apps have turned off) and are thus
size-sensitive.
Note that the other "defs" (ngPipeDef, etc) will be
prefixed and shortened in follow-up PRs, in an attempt to
limit how large and conflict-y this change is.
PR Close#33116
Directive defs are not considered public API, so the property
that contains them should be prefixed with Angular's marker
for "private" ('ɵ') to discourage apps from relying on def
APIs directly.
This commit adds the prefix and shortens the name from
ngDirectiveDef to dir. This is because property names
cannot be minified by Uglify without turning on property
mangling (which most apps have turned off) and are thus
size-sensitive.
Note that the other "defs" (ngFactoryDef, etc) will be
prefixed and shortened in follow-up PRs, in an attempt to
limit how large and conflict-y this change is.
PR Close#33110
Component defs are not considered public API, so the property
that contains them should be prefixed with Angular's marker
for "private" ('ɵ') to discourage apps from relying on def
APIs directly.
This commit adds the prefix and shortens the name from
`ngComponentDef` to `cmp`. This is because property names
cannot be minified by Uglify without turning on property
mangling (which most apps have turned off) and are thus
size-sensitive.
Note that the other "defs" (ngDirectiveDef, etc) will be
prefixed and shortened in follow-up PRs, in an attempt to
limit how large and conflict-y this change is.
PR Close#33088
For v9 we want the migration to the new i18n to be as
simple as possible.
Previously the developer had to positively choose to use
legacy messsage id support in the case that their translation
files had not been migrated to the new format by setting the
`legacyMessageIdFormat` option in tsconfig.json to the format
of their translation files.
Now this setting has been changed to `enableI18nLegacyMessageFormat`
as is a boolean that defaults to `true`. The format is then read from
the `i18nInFormat` option, which was previously used to trigger translations
in the pre-ivy angular compiler.
PR Close#33053
The `$localize` library uses a new message digest function for
computing message ids. This means that translations in legacy
translation files will no longer match the message ids in the code
and so will not be translated.
This commit adds the ability to specify the format of your legacy
translation files, so that the appropriate message id can be rendered
in the `$localize` tagged strings. This results in larger code size
and requires that all translations are in the legacy format.
Going forward the developer should migrate their translation files
to use the new message id format.
PR Close#32937
This commit changes the Angular compiler (ivy-only) to generate `$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
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
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
To improve cross platform support, all file access (and path manipulation)
is now done through a well known interface (`FileSystem`).
For testing a number of `MockFileSystem` implementations are provided.
These provide an in-memory file-system which emulates operating systems
like OS/X, Unix and Windows.
The current file system is always available via the static method,
`FileSystem.getFileSystem()`. This is also used by a number of static
methods on `AbsoluteFsPath` and `PathSegment`, to avoid having to pass
`FileSystem` objects around all the time. The result of this is that one
must be careful to ensure that the file-system has been initialized before
using any of these static methods. To prevent this happening accidentally
the current file system always starts out as an instance of `InvalidFileSystem`,
which will throw an error if any of its methods are called.
You can set the current file-system by calling `FileSystem.setFileSystem()`.
During testing you can call the helper function `initMockFileSystem(os)`
which takes a string name of the OS to emulate, and will also monkey-patch
aspects of the TypeScript library to ensure that TS is also using the
current file-system.
Finally there is the `NgtscCompilerHost` to be used for any TypeScript
compilation, which uses a given file-system.
All tests that interact with the file-system should be tested against each
of the mock file-systems. A series of helpers have been provided to support
such tests:
* `runInEachFileSystem()` - wrap your tests in this helper to run all the
wrapped tests in each of the mock file-systems.
* `addTestFilesToFileSystem()` - use this to add files and their contents
to the mock file system for testing.
* `loadTestFilesFromDisk()` - use this to load a mirror image of files on
disk into the in-memory mock file-system.
* `loadFakeCore()` - use this to load a fake version of `@angular/core`
into the mock file-system.
All ngcc and ngtsc source and tests now use this virtual file-system setup.
PR Close#30921
Optimizations to skip compiling source files that had not changed
did not account for the case where only a resource file changes,
such as an external template or style file.
Now we track such dependencies and trigger a recompilation
if any of the previously tracked resources have changed.
This will require a change on the CLI side to provide the list of
resource files that changed to trigger the current compilation by
implementing `CompilerHost.getModifiedResourceFiles()`.
Closes#30947
PR Close#30954
ngtsc previously could attempt to reuse the main ts.Program twice. This
occurred when template type-checking was enabled and then an incremental
build was performed. This breaks a TypeScript invariant - ts.Programs can
only be reused once.
The creation of the template type-checking program reuses the main program,
rendering it moot. Then, on the next incremental build the main program
would be subject to reuse again, which would crash inside TypeScript.
This commit fixes the issue by reusing the template type-checking program
from the previous run on the next incremental build. Since under normal
circumstances the files in the type-checking program aren't changed, this
should be just as fast.
Testing strategy: a test is added in the incremental_spec which validates
that program reuse with type-checking turned on does not crash the compiler.
Fixes#30079
PR Close#30090
The compiler uses metadata to represent what it statically knows about
various expressions in a program. Occasionally, expressions in the program
for which metadata is extracted may contain sub-expressions which are not
representable in metadata. One such construct is an arrow function.
The compiler does not always need to understand such expressions completely.
For example, for a provider defined with `useValue`, the compiler does not
need to understand the value at all, only the outer provider definition. In
this case, the compiler employs a technique known as "expression lowering",
where it rewrites the provider expression into one that can be represented
in metadata. Chiefly, this involves extracting out the dynamic part (the
`useValue` expression) into an exported constant.
Lowering is applied through a heuristic, which considers the containing
statement as well as the field name of the expression.
Previously, this heuristic was not completely accurate in the case of
route definitions and the `loadChildren` field, which is lowered. If the
route definition using `loadChildren` existed inside a decorator invocation,
lowering was performed correctly. However, if it existed inside a standalone
variable declaration with an export keyword, the heuristic would conclude
that lowering was unnecessary. For ordinary providers this is true; however
the compiler attempts to fully understand the ROUTES token and thus even if
an array of routes is declared in an exported variable, any `loadChildren`
expressions within still need to be lowered.
This commit enables lowering of already exported variables under a limited
set of conditions (where the initializer expression is of a specific form).
This should enable the use of `loadChildren` in route definitions.
PR Close#30038
Template type-checking is enabled by default in the View Engine compiler.
The feature in Ivy is not quite ready for this yet, so this flag will
temporarily control whether templates are type-checked in ngtsc.
The goal is to remove this flag after rolling out template type-checking in
google3 in Ivy mode, and making sure the feature is as compatible with the
View Engine implementation as possible.
Initially, the default value of the flag will leave checking disabled.
PR Close#29698
This commit adds support for compiling the same program repeatedly in a way
that's similar to how incremental builds work in a tool such as the CLI.
* support is added to the compiler entrypoint for reuse of the Program
object between compilations. This is the basis of the compiler's
incremental compilation model.
* support is added to wrap the CompilerHost the compiler creates and cache
ts.SourceFiles in between compilations.
* support is added to track when files are emitted, for assertion purposes.
* an 'exclude' section is added to the base tsconfig to prevent .d.ts
outputs from the first compilation from becoming inputs to any subsequent
compilations.
PR Close#29380
This commit adds a `tracePerformance` option for tsconfig.json. When
specified, it causes a JSON file with timing information from the ngtsc
compiler to be emitted at the specified path.
This tracing system is used to instrument the analysis/emit phases of
compilation, and will be useful in debugging future integration work with
@angular/cli.
See ngtsc/perf/README.md for more details.
PR Close#29380
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
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
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
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
