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
Currently, when Angular code is built with Bazel and with Ivy, generated
factory shims (.ngfactory files) are not processed via the majority of
tsickle's transforms. This is a subtle effect of the build infrastructure,
but it boils down to a TsickleHost method `shouldSkipTsickleProcessing`.
For ngc_wrapped builds (Bazel + Angular), this method is defined in the
`@bazel/typescript` (aka bazel rules_typescript) implementation of
`CompilerHost`. The default behavior is to skip tsickle processing for files
which are not present in the original `srcs[]` of the build rule. In
Angular's case, this includes all generated shim files.
For View Engine factories this is probably desirable as they're quite
complex and they've never been tested with tsickle. Ivy factories however
are smaller and very straightforward, and it makes sense to treat them like
any other output.
This commit adjusts two independent implementations of
`shouldSkipTsickleProcessing` to enable transformation of Ivy shims:
* in `@angular/bazel` aka ngc_wrapped, the upstream `@bazel/typescript`
`CompilerHost` is patched to treat .ngfactory files the same as their
original source file, with respect to tsickle processing.
It is currently not possible to test this change as we don't have any test
that inspects tsickle output with bazel. It will be extensively tested in
g3.
* in `ngc`, Angular's own implementation is adjusted to allow for the
processing of shims when compiling with Ivy. This enables a unit test to
be written to validate the correct behavior of tsickle when given a host
that's appropriately configured to process factory shims.
For ngtsc-as-a-plugin, a similar fix will need to be submitted upstream in
tsc_wrapped.
PR Close#35848
PR Close#35975
Currently, when Angular code is built with Bazel and with Ivy, generated
factory shims (.ngfactory files) are not processed via the majority of
tsickle's transforms. This is a subtle effect of the build infrastructure,
but it boils down to a TsickleHost method `shouldSkipTsickleProcessing`.
For ngc_wrapped builds (Bazel + Angular), this method is defined in the
`@bazel/typescript` (aka bazel rules_typescript) implementation of
`CompilerHost`. The default behavior is to skip tsickle processing for files
which are not present in the original `srcs[]` of the build rule. In
Angular's case, this includes all generated shim files.
For View Engine factories this is probably desirable as they're quite
complex and they've never been tested with tsickle. Ivy factories however
are smaller and very straightforward, and it makes sense to treat them like
any other output.
This commit adjusts two independent implementations of
`shouldSkipTsickleProcessing` to enable transformation of Ivy shims:
* in `@angular/bazel` aka ngc_wrapped, the upstream `@bazel/typescript`
`CompilerHost` is patched to treat .ngfactory files the same as their
original source file, with respect to tsickle processing.
It is currently not possible to test this change as we don't have any test
that inspects tsickle output with bazel. It will be extensively tested in
g3.
* in `ngc`, Angular's own implementation is adjusted to allow for the
processing of shims when compiling with Ivy. This enables a unit test to
be written to validate the correct behavior of tsickle when given a host
that's appropriately configured to process factory shims.
For ngtsc-as-a-plugin, a similar fix will need to be submitted upstream in
tsc_wrapped.
PR Close#35848
The compiler exports a `formatDiagnostics` function which consumers can use
to print both ts and ng diagnostics. However, this function was previously
using the "old" style TypeScript diagnostics, as opposed to the modern
diagnostic printer which uses terminal colors and prints additional context
information.
This commit updates `formatDiagnostics` to use the modern formatter, plus to
update Ivy's negative error codes to Angular 'NG' errors.
The Angular CLI needs a little more work to use this function for printing
TS diagnostics, but this commit alone should fix Bazel builds as ngc-wrapped
goes through `formatDiagnostics`.
PR Close#34234
This commit changes the reporting of watch mode diagnostics for ngtsc to use
the same formatting as non-watch mode diagnostics. This prints rich and
contextual errors even in watch mode, which previously was not the case.
Fixes#32213
PR Close#33862
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 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
Versions of CLI prior to angular/angular-cli@0e339ee did not expose the host.getModifiedResourceFiles() method.
This meant that null was being passed through to the IncrementalState.reconcile() method
to indicate that there were either no changes or the host didn't support that method.
This commit fixes a bug where we were checking for undefined rather than null when
deciding whether any resource files had changed, causing a null reference error to be thrown.
This bug was not caught by the unit testing because the tests set up the changed files
via a slightly different process, not having access to the CompilerHost, and these test
were making the erroneous assumption that undefined indicated that there were no
changed files.
PR Close#31322
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
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
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
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 gets ready for the introduction of ngtsc template
type-checking tests by refactoring test environment setup into a
custom helper. This helper will simplify the authoring of future
ngtsc tests.
Ngtsc tests previously returned a numeric error code (a la ngtsc's CLI
interface) if any TypeScript errors occurred. The helper has the
ability to run ngtsc and return the actual array of ts.Diagnostics, which
greatly increases the ability to write clean tests.
PR Close#26203
TypeScript has a more modern diagnostic emit function which produces
contextually annotated error information, using colors in the console
to indicate where in the code the error occurs.
This commit swiches ngtsc to use this format for diagnostics when
emitting them after a failed compilation.
PR Close#25647
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
The errors produced when error were encountered while interpreting the
content of a directive was often incomprehencible. With this change
these kind of error messages should be easier to understand and diagnose.
PR Close#20459
Usages of `NgTools_InternalApi_NG_2` from `@angular/compiler-cli` will now
throw an error.
Adds `listLazyRoutes` to `@angular/compiler-cli/ngtools2.ts` for getting
the lazy routes of a `ng.Program`.
PR Close#19836
If no user files changed:
- only type check the changed generated files
Never emit non changed generated files
- we still calculate them, but don’t send them through
TypeScript to emit them but cache the written files instead.
PR Close#19646
For now, we always create all generated files, but diff them
before we pass them to TypeScript.
For the user files, we compare the programs and only emit changed
TypeScript files.
This also adds more diagnostic messages if the `—diagnostics` flag
is passed to the command line.
Closure no longer needs to have the imports rewritten avoid rewriting
as this can cause issues when the source directory structure differs
from what is deployed.
Fixes: #19026
- temporarily keeps the old sources under packages/tsc-wrapped
until the build scripts are changed to use compiler-cli everywhere.
- removes the compiler options `disableTransformerPipeline` that was introduced
in a previous beta of Angular 5, i.e. the transformer based compiler
is now always enabled.
PR Close#18966
With this change ngc now accepts a `-w` or a `--watch`
command-line option that will automatically perform a
recompile whenever any source files change on disk.
PR Close#18818
With this change ngc now accepts a `-w` or a `--watch`
command-line option that will automatically perform a
recompile whenever any source files change on disk.
PR Close#18818
The source map does not currently work with the transformer pipeline.
It will be re-enabled after TypeScript 2.4 is made the min version.
To revert to the former compiler, use the `disableTransformerPipeline` in
tsconfig.json:
```
{
"angularCompilerOptions": {
"disableTransformerPipeline": true
}
}
```
