This commit finishes the removal of View Engine from the codebase, deleting
those pieces of @angular/compiler which were only used for VE.
Co-Authored-By: JoostK <joost.koehoorn@gmail.com>
PR Close#44368
This commit does a first-pass removal of the View Engine infrastructure
in compiler-cli. A more in-depth cleanup is necessary and large parts
of the View Engine compiler infrastructure remain within
`@angular/compiler`, this is just a first cleanup step.
PR Close#44269
The View Engine compiler now throws when constructed and will be removed shortly. Direct users should switch to `NgtscProgram` to build with [Ivy](https://angular.io/guide/ivy). The View Engine compiler is being removed, so this makes it throw an error to ensure no one accidentally depends on code being removed.
PR Close#43862
Similar to the other private entry-points we have added for localize,
bazel or the migrations, we should expose the tooling code through
a dedicated private export. This will make the compiler-cli exports
more consistent and it will become easier for the CLI to export
necessary code.
PR Close#43431
As outlined in the previous commit which enabled the `esModuleInterop`
TypeScript compiler option, we need to update all namespace imports
for `typescript` to default imports. This is needed to allow for
TypeScript to be imported at runtime from an ES module.
Similar changes are needed for modules like `semver` where the types incorrectly
suggest named exports that will not exist at runtime when imported from ESM.
This commit refactors all imports to match with the lint rule we have
configured in the previous commit. See the previous commit for more
details on why certain imports have been changed.
A special case are the imports to `@babel/core` and `@babel/types`. For
these a special interop is needed as both default imports, or named
imports break the other module format. e.g default imports would work
well for ESM, but it breaks for CJS. For CJS, the named imports would
only work, but in ESM, only the default export exist. We work around
this for now until the devmode is using ESM as well (which would be
consistent with prodmode and gives us more valuable test results). More
details on the interop can be found in the `babel_core.ts` files (two
interops are needed for both localize/or the compiler-cli).
PR Close#43431
Now that `Route.loadChildren` no longer accepts a string, there is no
need for tooling to find all string-based `loadChildren` to setup lazy
imports for them. As a result, the `listLazyRoutes` operation that
enumerates all string-based `loadChildren` occurrences is no longer
needed and is therefore removed from the compiler.
The `listLazyRoutes` API remains on the `Program` interface to avoid
breaking external tools that may be using this method, but those tools
should ultimately move away from using this API.
PR Close#43591
This commit moves some xi18n-related functions in the View Engine
ng.Program into a new file. This is necessary in order to depend on them
from the Ivy ng.Program while avoiding a cycle.
PR Close#42485
For quite a while it is an unspoken convention to add a trailing
new-line files within the Angular repository. This was never enforced
automatically, but has been frequently raised in pull requests through
manual review. This commit sets up a lint rule so that this is
"officially" enforced and doesn't require manual review.
PR Close#42478
When an Ivy NgModule is imported into a View Engine build, it doesn't have
metadata.json files that describe it as an NgModule, so it appears to VE
builds as a plain, undecorated class. The error message shown in this
situation generic and confusing, since it recommends adding an @NgModule
annotation to a class from a library.
This commit adds special detection into the View Engine compiler to give a
more specific error message when an Ivy NgModule is imported.
PR Close#41534
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: 401ef71ae5 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
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
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 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
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
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
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
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
Closure requires @nocollapse on Ivy definition static fields in order
to not convert them to standalone constants. However tsickle, the tool
which would ordinarily be responsible for adding @nocollapse, doesn't
properly annotate fields which are added synthetically via transforms.
So this commit adds @nocollapse by applying regular expressions against
code during the final write to disk.
PR Close#25775
All errors for existing fields have been detected and suppressed with a
`!` assertion.
Issue/24571 is tracking proper clean up of those instances.
One-line change required in ivy/compilation.ts, because it appears that
the new syntax causes tsickle emitted node to no longer track their
original sourceFiles.
PR Close#24572
Bazel has a restriction that a single output (eg. a compiled version of
//packages/common) can only be produced by a single rule. This precludes
the Angular repo from having multiple rules that build the same code. And
the complexity of having a single rule produce multiple outputs (eg. an
ngc-compiled version of //packages/common and an Ivy-enabled version) is
too high.
Additionally, the Angular repo has lots of existing tests which could be
executed as-is under Ivy. Such testing is very valuable, and it would be
nice to share not only the code, but the dependency graph / build config
as well.
Thus, this change introduces a --define flag 'compile' with three potential
values. When --define=compile=X is set, the entire build system runs in a
particular mode - the behavior of all existing targets is controlled by
the flag. This allows us to reuse our entire build structure for testing
in a variety of different manners. The flag has three possible settings:
* legacy (the default): the traditional View Engine (ngc) build
* local: runs the prototype ngtsc compiler, which does not rely on global
analysis
* jit: runs ngtsc in a mode which executes tsickle, but excludes the
Angular related transforms, which approximates the behavior of plain
tsc. This allows the main packages such as common to be tested with
the JIT compiler.
Additionally, the ivy_ng_module() rule still exists and runs ngc in a mode
where Ivy-compiled output is produced from global analysis information, as
a stopgap while ngtsc is being developed.
PR Close#24056
This commit adds a new compiler pipeline that isn't dependent on global
analysis, referred to as 'ngtsc'. This new compiler is accessed by
running ngc with "enableIvy" set to "ngtsc". It reuses the same initialization
logic but creates a new implementation of Program which does not perform the
global-level analysis that AngularCompilerProgram does. It will be the
foundation for the production Ivy compiler.
PR Close#23455
Lowering expressions in flat module metadata is desirable, but it won't
work without some rearchitecting. Currently the flat module index source
is added to the Program and therefore must be determined before the rest
of the transforms run. Since the lowering transform changes the set of
exports needed in the index, this creates a catch-22 in the index
generation.
This commit causes the flat module index metadata to be generated using
only those transforms which are "safe" (don't modify the index).
PR Close#23226
Currently, the flat module index metadata is produced directly from
the source metadata. The compiler, however, applies transformations
on the Typescript sources during transpilation, and also equivalent
transformations on the metadata itself. This transformed metadata
doesn't end up in the flat module index.
This changes the compiler to generate the flat module index metadata
from its transformed version instead of directly from source.
PR Close#23129
Computing the value of loadChildren does not work externally, as the CLI
needs to be able to detect the paths referenced to properly set up
codesplitting. However, internally, different approaches to codesplitting
require hashed module IDs, and the computation of those hashes involves
something like:
{path: '...', loadChildren: hashFn('module')}
ngc should lower loadChildren into an exported constant in that case.
This will never break externally, because loadChildren is always a
string externally, and a string won't get lowered.
PR Close#23088
ngc knows to filter out d.ts inputs, but the logic accidentally
depended on whether it had a previous Program lying around.
Fixing that logic puts ngc on the fast code path, but in that code
path it must be able to merge tsickle EmitResults, so we need to
plumb the tsickle.mergeEmitResults function through all the intervening
APIs. The bulk of this change is that plumbing.
PR Close#22899
This adds compilation of @NgModule providers and imports into
ngInjectorDef statements in generated code. All @NgModule annotations
will be compiled and the @NgModule decorators removed from the
resultant js output.
All @Injectables will also be compiled in Ivy mode, and the decorator
removed.
PR Close#22458
BREAKING CHANGE:
The `<template>` tag was deprecated in Angular v4 to avoid collisions (i.e. when
using Web Components).
This commit removes support for `<template>`. `<ng-template>` should be used
instead.
BEFORE:
<!-- html template -->
<template>some template content</template>
# tsconfig.json
{
# ...
"angularCompilerOptions": {
# ...
# This option is no more supported and will have no effect
"enableLegacyTemplate": [true|false]
}
}
AFTER:
<!-- html template -->
<ng-template>some template content</ng-template>
PR Close#22783
Closure has a transformation which turns:
Service.ngInjectableDef = ...;
into:
Service$ngInjectableDef = ...;
This transformation obviously breaks Ivy in a major way. The solution is
to annotate the fields as @nocollapse. However, Typescript appears to ignore
synthetic comments added to a node during a transformation, so the "right"
way to add these comments doesn't work.
As an interim measure, a post-processing step just before the compiled JS is
written to disk appends the correct comments with a regular expression.
PR Close#22691
