In ES5 code, TypeScript requires certain helpers (such as
`__spreadArrays()`) to be able to support ES2015+ features. These
helpers can be either imported from `tslib` (by setting the
`importHelpers` TS compiler option to `true`) or emitted inline (by
setting the `importHelpers` and `noEmitHelpers` TS compiler options to
`false`, which is the default value for both).
Ngtsc's `StaticInterpreter` (which is also used during ngcc processing)
is able to statically evaluate some of these helpers (currently
`__assign()`, `__spread()` and `__spreadArrays()`), as long as
`ReflectionHost#getDefinitionOfFunction()` correctly detects the
declaration of the helper. For this to happen, the left-hand side of the
corresponding call expression (i.e. `__spread(...)` or
`tslib.__spread(...)`) must be evaluated as a function declaration for
`getDefinitionOfFunction()` to be called with.
In the case of imported helpers, the `tslib.__someHelper` expression was
resolved to a function declaration of the form
`export declare function __someHelper(...args: any[][]): any[];`, which
allows `getDefinitionOfFunction()` to correctly map it to a TS helper.
In contrast, in the case of emitted helpers (and regardless of the
module format: `CommonJS`, `ESNext`, `UMD`, etc.)), the `__someHelper`
identifier was resolved to a variable declaration of the form
`var __someHelper = (this && this.__someHelper) || function () { ... }`,
which upon further evaluation was categorized as a `DynamicValue`
(prohibiting further evaluation by the `getDefinitionOfFunction()`).
As a result of the above, emitted TypeScript helpers were not evaluated
in ES5 code.
---
This commit changes the detection of TS helpers to leverage the existing
`KnownFn` feature (previously only used for built-in functions).
`Esm5ReflectionHost` is changed to always return `KnownDeclaration`s for
TS helpers, both imported (`getExportsOfModule()`) as well as emitted
(`getDeclarationOfIdentifier()`).
Similar changes are made to `CommonJsReflectionHost` and
`UmdReflectionHost`.
The `KnownDeclaration`s are then mapped to `KnownFn`s in
`StaticInterpreter`, allowing it to statically evaluate call expressions
involving any kind of TS helpers.
Jira issue: https://angular-team.atlassian.net/browse/FW-1689
PR Close#35191
ngcc uses a lockfile to prevent two ngcc instances from executing at the
same time. Previously, if a lockfile was found the current process would
error and exit.
Now, when in async mode, the current process is able to wait for the previous
process to release the lockfile before continuing itself.
PR Close#35131
To support parallel CLI builds we instruct developers to pre-process
their node_modules via ngcc at the command line.
Despite doing this ngcc was still trying to set a lock when it was being
triggered by the CLI for packages that are not going to be processed,
since they are not compiled by Angular for instance.
This commit checks whether a target package needs to be compiled
at all before attempting to set the lock.
Fixes#35000
PR Close#35057
If ngcc gets updated to a new version then the artifacts
left in packages that were processed by the previous
version are possibly invalid.
Previously we just errored if we found packages that
had already been processed by an outdated version.
Now we automatically clean the packages that have
outdated artifacts so that they can be reprocessed
correctly with the current ngcc version.
Fixes#35082
PR Close#35079
This change reverts https://github.com/angular/angular/pull/28711
NOTE: This change deletes code and creates a BROKEN SHA. If reverting this SHA needs to be reverted with the next SHA to get back into a valid state.
The change removes the fact that `NgStyle`/`NgClass` is special and colaborates with the `[style]`/`[class]` to merge its styles. By reverting to old behavior we have better backwards compatiblity since it is no longer treated special and simply overwrites the styles (same as VE)
PR Close#34616
This change moves information from instructions to declarative position:
- `ɵɵallocHostVars(vars)` => `DirectiveDef.hostVars`
- `ɵɵelementHostAttrs(attrs)` => `DirectiveDef.hostAttrs`
When merging directives it is necessary to know about `hostVars` and `hostAttrs`. Before this change the information was stored in the `hostBindings` function. This was problematic, because in order to get to the information the `hostBindings` would have to be executed. In order for `hostBindings` to be executed the directives would have to be instantiated. This means that the directive instantiation would happen before we had knowledge about the `hostAttrs` and as a result the directive could observe in the constructor that not all of the `hostAttrs` have been applied. This further complicates the runtime as we have to apply `hostAttrs` in parts over many invocations.
`ɵɵallocHostVars` was unnecessarily complicated because it would have to update the `LView` (and Blueprint) while existing directives are already executing. By moving it out of `hostBindings` function we can access it statically and we can create correct `LView` (and Blueprint) in a single pass.
This change only changes how the instructions are generated, but does not change the runtime much. (We cheat by emulating the old behavior by calling `ɵɵallocHostVars` and `ɵɵelementHostAttrs`) Subsequent change will refactor the runtime to take advantage of the static information.
PR Close#34683
Consider a library that uses a shared constant for host bindings. e.g.
```ts
export const BASE_BINDINGS= {
'[class.mat-themed]': '_isThemed',
}
----
@Directive({
host: {...BASE_BINDINGS, '(click)': '...'}
})
export class Dir1 {}
@Directive({
host: {...BASE_BINDINGS, '(click)': '...'}
})
export class Dir2 {}
```
Previously when these components were shipped as part of the
library to NPM, consumers were able to consume `Dir1` and `Dir2`.
No errors showed up.
Now with Ivy, when ngcc tries to process the library, an error
will be thrown. The error is stating that the host bindings should
be an object (which they obviously are). This happens because
TypeScript transforms the object spread to individual
`Object.assign` calls (for compatibility).
The partial evaluator used by the `@Directive` annotation handler
is unable to process this expression because there is no
integrated support for `Object.assign`. In View Engine, this was
not a problem because the `metadata.json` files from the library
were used to compute the host bindings.
Fixes#34659
PR Close#34661
Ngcc adds properties to the `package.json` files of the entry-points it
processes to mark them as processed for a format and point to the
created Ivy entry-points (in case of `--create-ivy-entry-points`). When
running ngcc in parallel mode (which is the default for the standalone
ngcc command), multiple formats can be processed simultaneously for the
same entry-point and the order of completion is not deterministic.
Previously, ngcc would append new properties at the end of the target
object in `package.json` as soon as the format processing was completed.
As a result, the order of properties in the resulting `package.json`
(when processing multiple formats for an entry-point in parallel) was
not deterministic. For tools that use file hashes for caching purposes
(such as Bazel), this lead to a high probability of cache misses.
This commit fixes the problem by ensuring that the position of
properties added to `package.json` files is deterministic and
independent of the order in which each format is processed.
Jira issue: [FW-1801](https://angular-team.atlassian.net/browse/FW-1801)
Fixes#34635
PR Close#34870
Previously, it was possible for multiple instance of ngcc to be running
at the same time, but this is not supported and can cause confusing and
flakey errors at build time.
Now, only one instance of ngcc can run at a time. If a second instance
tries to execute it fails with an appropriate error message.
See https://github.com/angular/angular/issues/32431#issuecomment-571825781
PR Close#34722
Since I was learning the codebase and had a hard time understanding what was going on I've done a
bunch of changes in one commit that under normal circumstances should have been split into several
commits. Because this code is likely going to be overwritten with Misko's changes I'm not going to
spend the time with trying to split this up.
Overall I've done the following:
- I processed review feedback from #34307
- I did a bunch of renaming to make the code easier to understand
- I refactored some internal functions that were either inefficient or hard to read
- I also updated lots of type signatures to correct them and to remove many casts in the code
PR Close#34307
Previously the identifiers used in the typings files were the same as
those used in the source files.
When the typings files and the source files do not match exactly, e.g.
when one of them is flattened, while the other is a deep tree, it is
possible for identifiers to be renamed.
This commit ensures that the correct identifier is used in typings files
when the typings file does not export the same name as the source file.
Fixes https://github.com/angular/ngcc-validation/pull/608
PR Close#34254
The undecorated child migration creates a synthetic decorator, which
contained `"exportAs": ["exportName"]` as obtained from the metadata of
the parent class. This is a problem, as `exportAs` needs to specified
as a comma-separated string instead of an array. This commit fixes the
bug by transforming the array of export names back to a comma-separated
string.
PR Close#34014
By ensuring that legacy i18n message ids are rendered into the templates
of components for packages processed by ngcc, we ensure that these packages
can be used in an application that may provide translations in a legacy
format.
Fixes#34056
PR Close#34135
For injectables, we currently generate a factory function in the
injectable def (prov) that delegates to the factory function in
the factory def (fac). It looks something like this:
```
factory: function(t) { return Svc.fac(t); }
```
The extra wrapper function is unnecessary since the args for
the factory functions are the same. This commit changes the
compiler to generate this instead:
```
factory: Svc.fac
```
Because we are generating less code for each injectable, we
should see some modest code size savings. AIO's main bundle
is about 1 KB smaller.
PR Close#34076
Previously, the Angular AOT compiler would always add a
`ɵprov` to injectables. But in ngcc this resulted in duplicate `ɵprov`
properties since published libraries already have this property.
Now in ngtsc, trying to add a duplicate `ɵprov` property is an error,
while in ngcc the additional property is silently not added.
// FW-1750
PR Close#34085
Recently the ngtsc translator was modified to be more `ScriptTarget`
aware, which basically means that it will not generate non-ES5 code
when the output format is ES5 or similar.
This commit enhances that change by also "downleveling" localized
messages. In ES2015 the messages use tagged template literals, which
are not available in ES5.
PR Close#33857
This commit transforms the setClassMetadata calls generated by ngtsc from:
```typescript
/*@__PURE__*/ setClassMetadata(...);
```
to:
```typescript
/*@__PURE__*/ (function() {
setClassMetadata(...);
})();
```
Without the IIFE, terser won't remove these function calls because the
function calls have arguments that themselves are function calls or other
impure expressions. In order to make the whole block be DCE-ed by terser,
we wrap it into IIFE and mark the IIFE as pure.
It should be noted that this change doesn't have any impact on CLI* with
build-optimizer, which removes the whole setClassMetadata block within
the webpack loader, so terser or webpack itself don't get to see it at
all. This is done to prevent cross-chunk retention issues caused by
webpack's internal module registry.
* actually we do expect a short-term size regression while
https://github.com/angular/angular-cli/pull/16228
is merged and released in the next rc of the CLI. But long term this
change does nothing to CLI + build-optimizer configuration and is done
primarly to correct the seemingly correct but non-function PURE annotation
that builds not using build-optimizer could rely on.
PR Close#33337
In #32902 a bug was supposedly fixed where internal classes as used
within `ModuleWithProviders` are publicly exported, even when the
typings file already contained the generic type on the
`ModuleWithProviders`. This fix turns out to have been incomplete, as
the `ModuleWithProviders` analysis is not done when not processing the
typings files.
The effect of this bug is that formats that are processed after the
initial format had been processed would not have exports for internal
symbols, resulting in "export '...' was not found in '...'" errors.
This commit fixes the bug by always running the `ModuleWithProviders`
analyzer. An integration test has been added that would fail prior to
this change.
Fixes#33701
PR Close#33875
ngcc has a basic integration test infrastructure that downlevels
TypeScript code into bundle formats that need to be processed by ngcc.
Until now, only ES5 bundles were created with a flat structure, however
more complex scenarios require an APF-like layout containing multiple
bundle formats.
PR Close#33875
Previously, ngcc's `Renderer` would add some constants in the processed
files which were emitted as ES2015 code (e.g. `const` declarations).
This would result in invalid ES5 generated code that would break when
run on browsers that do not support the emitted format.
This commit fixes it by adding a `printStatement()` method to
`RenderingFormatter`, which can convert statements to JavaScript code in
a suitable format for the corresponding `RenderingFormatter`.
Additionally, the `translateExpression()` and `translateStatement()`
ngtsc helper methods are augmented to accept an extra hint to know
whether the code needs to be translated to ES5 format or not.
Fixes#32665
PR Close#33514
While processing class metadata, ngtsc generates a `setClassMetadata()`
call which (among other things) contains info about property decorators.
Previously, processing getter/setter pairs with some of ngcc's
`ReflectionHost`s resulted in multiple metadata entries for the same
property, which resulted in duplicate object keys, which in turn causes
an error in ES5 strict mode.
This commit fixes it by ensuring that there are no duplicate property
names in the `setClassMetadata()` calls.
In addition, `generateSetClassMetadataCall()` is updated to treat
`ClassMember#decorators: []` the same as `ClassMember.decorators: null`
(i.e. omitting the `ClassMember` from the generated `setClassMetadata()`
call). Alternatively, ngcc's `ReflectionHost`s could be updated to do
this transformation (`decorators: []` --> `decorators: null`) when
reflecting on class members, but this would require changes in many
places and be less future-proof.
For example, given a class such as:
```ts
class Foo {
@Input() get bar() { return 'bar'; }
set bar(value: any) {}
}
```
...previously the generated `setClassMetadata()` call would look like:
```ts
ɵsetClassMetadata(..., {
bar: [{type: Input}],
bar: [],
});
```
The same class will now result in a call like:
```ts
ɵsetClassMetadata(..., {
bar: [{type: Input}],
});
```
Fixes#30569
PR Close#33514
When ngcc is configured to generate reexports for a package using the
`generateDeepReexports` configuration option, it could incorrectly
render the reexports as often as the number of compiled classes in the
declaration file. This would cause compilation errors due to duplicated
declarations.
PR Close#33658
In Angular View Engine, there are two kinds of decorator inheritance:
1) both the parent and child classes have decorators
This case is supported by InheritDefinitionFeature, which merges some fields
of the definitions (such as the inputs or queries).
2) only the parent class has a decorator
If the child class is missing a decorator, the compiler effectively behaves
as if the parent class' decorator is applied to the child class as well.
This is the "undecorated child" scenario, and this commit adds a migration
to ngcc to support this pattern in Ivy.
This migration has 2 phases. First, the NgModules of the application are
scanned for classes in 'declarations' which are missing decorators, but
whose base classes do have decorators. These classes are the undecorated
children. This scan is performed recursively, so even if a declared class
has a base class that itself inherits a decorator, this case is handled.
Next, a synthetic decorator (either @Component or @Directive) is created
on the child class. This decorator copies some critical information such
as 'selector' and 'exportAs', as well as supports any decorated fields
(@Input, etc). A flag is passed to the decorator compiler which causes a
special feature `CopyDefinitionFeature` to be included on the compiled
definition. This feature copies at runtime the remaining aspects of the
parent definition which `InheritDefinitionFeature` does not handle,
completing the "full" inheritance of the child class' decorator from its
parent class.
PR Close#33362
This commit adapts the private NgModule re-export system (using aliasing) to
ngcc. Not all ngcc compilations are compatible with these re-exports, as
they assume a 1:1 correspondence between .js and .d.ts files. The primary
concern here is supporting them for commonjs-only packages.
PR Close#33177
`ngcc` supports both synchronous and asynchronous execution. The default
mode when using `ngcc` programmatically (which is how `@angular/cli` is
using it) is synchronous. When running `ngcc` from the command line
(i.e. via the `ivy-ngcc` script), it runs in async mode.
Previously, the work would be executed in the same way in both modes.
This commit improves the performance of `ngcc` in async mode by
processing tasks in parallel on multiple processes. It uses the Node.js
built-in [`cluster` module](https://nodejs.org/api/cluster.html) to
launch a cluster of Node.js processes and take advantage of multi-core
systems.
Preliminary comparisons indicate a 1.8x to 2.6x speed improvement when
processing the angular.io app (apparently depending on the OS, number of
available cores, system load, etc.). Further investigation is needed to
better understand these numbers and identify potential areas of
improvement.
Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1
Original design doc: https://hackmd.io/uYG9CJrFQZ-6FtKqpnYJAA?view
Jira issue: [FW-1460](https://angular-team.atlassian.net/browse/FW-1460)
PR Close#32427
In the past, a task's processability didn't use to be known in advance.
It was possible that a task would be created and added to the queue
during the analysis phase and then later (during the compilation phase)
it would be found out that the task (i.e. the associated format
property) was not processable.
As a result, certain checks had to be delayed, until a task's processing
had started or even until all tasks had been processed. Examples of
checks that had to be delayed are:
- Whether a task can be skipped due to `compileAllFormats: false`.
- Whether there were entry-points for which no format at all was
successfully processed.
It turns out that (as made clear by the refactoring in 9537b2ff8), once
a task starts being processed it is expected to either complete
successfully (with the associated format being processed) or throw an
error (in which case the process will exit). In other words, a task's
processability is known in advance.
This commit takes advantage of this fact by moving certain checks
earlier in the process (e.g. in the analysis phase instead of the
compilation phase), which in turn allows avoiding some unnecessary work.
More specifically:
- When `compileAllFormats` is `false`, tasks are created _only_ for the
first suitable format property for each entry-point, since the rest of
the tasks would have been skipped during the compilation phase anyway.
This has the following advantages:
1. It avoids the slight overhead of generating extraneous tasks and
then starting to process them (before realizing they should be
skipped).
2. In a potential future parallel execution mode, unnecessary tasks
might start being processed at the same time as the first (useful)
task, even if their output would be later discarded, wasting
resources. Alternatively, extra logic would have to be added to
prevent this from happening. The change in this commit avoids these
issues.
- When an entry-point is not processable, an error will be thrown
upfront without having to wait for other tasks to be processed before
failing.
PR Close#32427
Previously, `ngcc`'s programmatic API would run and complete
synchronously. This was necessary for specific usecases (such as how the
`@angular/cli` invokes `ngcc` as part of the TypeScript module
resolution process), but not for others (e.g. running `ivy-ngcc` as a
`postinstall` script).
This commit adds a new option (`async`) that enables turning on
asynchronous execution. I.e. it signals that the caller is OK with the
function call to complete asynchronously, which allows `ngcc` to
potentially run in a more efficient mode.
Currently, there is no difference in the way tasks are executed in sync
vs async mode, but this change sets the ground for adding new execution
options (that require asynchronous operation), such as processing tasks
in parallel on multiple processes.
NOTE:
When using the programmatic API, the default value for `async` is
`false`, thus retaining backwards compatibility.
When running `ngcc` from the command line (i.e. via the `ivy-ngcc`
script), it runs in async mode (to be able to take advantage of future
optimizations), but that is transparent to the caller.
PR Close#32427
To persist some of its state, `ngcc` needs to update `package.json`
files (both in memory and on disk).
This refactoring abstracts these operations behind the
`PackageJsonUpdater` interface, making it easier to orchestrate them
from different contexts (e.g. when running tasks in parallel on multiple
processes).
Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1
PR Close#32427
Previously, any diagnostics reported during the compilation of an
entry-point would not be shown to the user, but either be ignored or
cause a hard crash in case of a `FatalDiagnosticError`. This is
unfortunate, as such error instances contain information on which code
was responsible for producing the error, whereas only its error message
would not. Therefore, it was quite hard to determine where the error
originates from.
This commit introduces behavior to deal with error diagnostics in a more
graceful way. Such diagnostics will still cause the compilation to fail,
however the error message now contains formatted diagnostics.
Closes#31977
Resolves FW-1374
PR Close#31996
Previously, `ngcc` assumed that if a format property was defined in
`package.json` it would point to a valid format-path (i.e. a file that
is an entry-point for a specific format). This is generally the case,
except if a format property is set to a non-string value (such as
`package.json`) - either directly in the `package.json` (which is unusual)
or in ngcc.config.js (which is a valid usecase, when one wants a
format property to be ignored by `ngcc`).
For example, the following config file would cause `ngcc` to throw:
```
module.exports = {
packages: {
'test-package': {
entryPoints: {
'.': {
override: {
fesm2015: undefined,
},
},
},
},
},
};
```
This commit fixes it by ensuring that only format properties whose value
is a string are considered by `ngcc`.
For reference, this regression was introduced in #32052.
Fixes#32188
PR Close#32205
Previously, when run with `createNewEntryPointFormats: true`, `ngcc`
would only update `package.json` with the new entry-point for the first
format property that mapped to a format-path. Subsequent properties
mapping to the same format-path would be detected as processed and not
have their new entry-point format recorded in `package.json`.
This commit fixes this by ensuring `package.json` is updated for all
matching format properties, when writing an `EntryPointBundle`.
PR Close#32052
Previously, `ngcc` would avoid processing a `formatPath` that a property
in `package.json` mapped to, if either the _property_ was marked as
processed or the `formatPath` (i.e. the file(s)) was processed in the
same `ngcc` run (since the `compiledFormats` set was not persisted
across runs).
This could lead in a situation where a `formatPath` would be compiled
twice (if for example properties `a` and `b` both mapped to the same
`formatPath` and one would run `ngcc` for property `a` and then `b`).
This commit fixes it by ensuring that as soon as a `formatPath` has been
processed all corresponding properties are marked as processed (which
persists across `ngcc` runs).
PR Close#32003
Previously, when `ngcc` needed to mark multiple properties as processed
(e.g. a processed format property and `typings` or all supported
properties for a non-Angular entry-point), it would update each one
separately and write the file to disk multiple times.
This commit changes this, so that multiple properties can be updated at
once with one file-write operation. While this theoretically improves
performance (reducing the I/O operations), it is not expected to have
any noticeable impact in practice, since these operations are a tiny
fraction of `ngcc`'s work.
This change will be useful for a subsequent change to mark all
properties that map to the same `formatPath` as processed, once it is
processed the first time.
PR Close#32003
There are scenarios where it is not possible for ngcc to guess the format
or configuration of an entry-point just from the files on disk.
Such scenarios include:
1) Unwanted entry-points: A spurious package.json makes ngcc think
there is an entry-point when there should not be one.
2) Deep-import entry-points: some packages allow deep-imports but do not
provide package.json files to indicate to ngcc that the imported path is
actually an entry-point to be processed.
3) Invalid/missing package.json properties: For example, an entry-point
that does not provide a valid property to a required format.
The configuration is provided by one or more `ngcc.config.js` files:
* If placed at the root of the project, this file can provide configuration
for named packages (and their entry-points) that have been npm installed
into the project.
* If published as part of a package, the file can provide configuration
for entry-points of the package.
The configured of a package at the project level will override any
configuration provided by the package itself.
PR Close#30591
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
When determining the module type of a bundle pointed to by the "main"
property, ngcc needs to read the bundle to figure out if it is CommonJS
or UMD format. However, when the "main" property does not exist ngcc
would crash while determining the path to the main bundle file.
This commit fixes the crash by checking if the "main" property is present
at all, before attempting to derive a full path to the bundle file.
Fixes#30916
Fixes FW-1369
PR Close#30950
This commit introduces a new interface, which abstracts access
to the underlying `FileSystem`. There is initially one concrete
implementation, `NodeJsFileSystem`, which is simply wrapping the
`fs` library of NodeJs.
Going forward, we can provide a `MockFileSystem` for test, which
should allow us to stop using `mock-fs` for most of the unit tests.
We could also implement a `CachedFileSystem` that may improve the
performance of ngcc.
PR Close#29643
By passing a `pathMappings` configuration (a subset of the
`ts.CompilerOptions` interface), we can instuct ngcc to process
additional paths outside the `node_modules` folder.
PR Close#29643
The test now attempts to compile an entry-point (@angular/common/http/testing)
that has a transient "private" dependency. A private dependency is one that is
only visible by looking at the compiled JS code, rather than the generated TS
typings files.
This proves that we can't rely on typings files alone for computing the
dependencies between entry-points.
PR Close#29643
Previously we always walked the whole folder tree looking for
entry-points before we tested whether a target package had been
processed already. This could take >10secs!
This commit does a quick check of the target package before doing
the full walk which brings down the execution time for ngcc in this
case dramatically.
```
$ time ./node_modules/.bin/ivy-ngcc -t @angular/common/http/testing
Compiling @angular/core : fesm2015 as esm2015
Compiling @angular/core : fesm5 as esm5
Compiling @angular/core : esm2015 as esm2015
Compiling @angular/core : esm5 as esm5
Compiling @angular/common/http : fesm2015 as esm2015
Compiling @angular/common/http : fesm5 as esm5
Compiling @angular/common/http : esm2015 as esm2015
Compiling @angular/common/http : esm5 as esm5
Compiling @angular/common/http/testing : fesm2015 as esm2015
Compiling @angular/common/http/testing : fesm5 as esm5
Compiling @angular/common/http/testing : esm2015 as esm2015
Compiling @angular/common/http/testing : esm5 as esm5
real 0m19.766s
user 0m28.533s
sys 0m2.262s
```
```
$ time ./node_modules/.bin/ivy-ngcc -t @angular/common/http/testing
The target entry-point has already been processed
real 0m0.666s
user 0m0.605s
sys 0m0.113s
```
PR Close#29740
George Kalpakas
Pete Bacon Darwin
Miško Hevery
Paul Gschwendtner
Igor Minar
JoostK
Kara Erickson
Alex Rickabaugh
Elvis Begovic
Alan Agius
Filipe Silva