Since we no longer hardcode the `package.json` for
entry-points, a bug has appeared for `ng_package` in Ivy.
The `package.json` files are populated incorrectly with Ivy
as the flat module bundle name is not propagated from `ng_module`
to the `ng_package` rule. The rule then guesses the index file
to `index.js` and does not respect the flat module bundle shim.
PR Close#36944
As of version 10, libraries following the APF will no longer contain
ESM5 output. Hence, tests in ngcc need to be updated as they currently
rely on the release output of `@angular/core`.
Additionally, we'd need to support in ngcc that the `module`
property of entry-points no longer necessarily refers to
`esm5` output, but instead can also target `esm2015`.
We currently achieve this by checking the path the `module`
property points to. We can do this because as per APF, the
folder name is known for the esm2015 output. Long-term for
more coverage, we want to sniff the format by looking for
known ES2015 constructs in the file `module` refers to.
PR Close#36944
In the past we added support for `ts_library` to `ng_package`. For those
targets we never can determine the "index" file. Unlike `ng_module`,
there is no provider data for flat module bundles, so the `ng_package`
rule assumes that the index file is simply called `index`.
This works as expected, but we also added logic in the past that doesn't
allow `ng_package` to add format properties (e.g. `main`, `module`) to a
`package.json` if a package json is handwritten for such a `ts_library` target.
This has been done that way because we assumed that such `package.json` files
might want to set format properties explicitly to different paths due to a
faulty "index" guess.
We want to change this behavior as most of the time a `package.json`
file already exists with just the module name. In those cases, the
packager should still set the format properties. We should only warn
and skip automatic insertion of the format properties if such a
`package.json` explicitly sets format properties.
PR Close#36944
We can remove all of the entry point resolution configuration from the package.json
in our source code as ng_package rule adds the properties automatically and correctly
configures them.
This change simplifies our code base but doesn't have any impact on the package.json
in the distributed npm_packages.
PR Close#36944
esm5 and fesm5 are no longer needed and have been deprecated in the past.
https://v9.angular.io/guide/deprecations#esm5-and-fesm5-code-formats-in-angular-npm-packages
This commit modifies ng_package to no longer distribute these two formats in npm packages
built by ng_package (e.g. @angular/core).
This commit intentionally doesn't fully clean up the ng_package rule to remove all traces of esm5 and fems5
build artifacts as that is a bigger cleanup and currently we are narrowing down the scope of this change
to the MVP needed for v10, which in this case is 'do not put esm5 and fesm5' into the npm packages.
More cleanup to follow: https://angular-team.atlassian.net/browse/FW-2143
BREAKING CHANGE: esm5 and fesm5 format is no longer distributed in
Angular's npm packages e.g. @angular/core
If you are not using Angular CLI to build your application or library,
and you need to be able to build es5 artifacts, then you will need to
downlevel the distributed Angular code to es5 on your own.
Angular CLI will automatically downlevel the code to es5 if differential
loading is enabled in the Angular project, so no action is required from
Angular CLI users.
PR Close#36944
In #36892 the `ModuleWithProviders` type parameter becomes required.
This exposes a bug in ngcc, where it can only handle functions that have a
specific form:
```
function forRoot() {
return { ... };
}
```
In other words, it only accepts functions that return an object literal.
In some libraries, the function instead returns a call to another function.
For example in `angular-in-memory-web-api`:
```
InMemoryWebApiModule.forFeature = function (dbCreator, options) {
return InMemoryWebApiModule_1.forRoot(dbCreator, options);
};
```
This commit changes the parsing of such functions to use the
`PartialEvaluator`, which can evaluate these more complex function
bodies.
PR Close#36948
Previously this method was implemented on the `NgccReflectionHost`,
but really it is asking too much of the host, since it actually needs to do
some static evaluation of the code to be able to support a wider range
of function shapes. Also there was only one implementation of the method
in the `Esm2015ReflectionHost` since it has no format specific code in
in.
This commit moves the whole function (and supporting helpers) into the
`ModuleWithProvidersAnalyzer`, which is the only place it was being used.
This class will be able to do further static evaluation of the function bodies
in order to support more function shapes than the host can do on its own.
The commit removes a whole set of reflection host tests but these are
already covered by the tests of the analyzer.
PR Close#36948
The purpose of the `WrappedValue` is to allow same object instance to be treated as different for the purposes of change detection. It is currently used with `async` pipe and only with `Observables`. The use case which it covers is if the `Observable` produces the same instance of the value but it is desirable to still try to mark it as changed for the purposes of change detection.
We believe tha the above use case is too rare to warrant special handling in the framework. (Having special handling causes application slowdown for the users and mental load for the developers.) No replacement is planned for this deprecation.
PR Close#36819
This optimization builds on a lot of prior work to finally make type-
checking of templates incremental.
Incrementality requires two main components:
- the ability to reuse work from a prior compilation.
- the ability to know when changes in the current program invalidate that
prior work.
Prior to this commit, on every type-checking pass the compiler would
generate new .ngtypecheck files for each original input file in the program.
1. (Build #1 main program): empty .ngtypecheck files generated for each
original input file.
2. (Build #1 type-check program): .ngtypecheck contents overridden for those
which have corresponding components that need type-checked.
3. (Build #2 main program): throw away old .ngtypecheck files and generate
new empty ones.
4. (Build #2 type-check program): same as step 2.
With this commit, the `IncrementalDriver` now tracks template type-checking
_metadata_ for each input file. The metadata contains information about
source mappings for generated type-checking code, as well as some
diagnostics which were discovered at type-check analysis time. The actual
type-checking code is stored in the TypeScript AST for type-checking files,
which is now re-used between programs as follows:
1. (Build #1 main program): empty .ngtypecheck files generated for each
original input file.
2. (Build #1 type-check program): .ngtypecheck contents overridden for those
which have corresponding components that need type-checked, and the
metadata registered in the `IncrementalDriver`.
3. (Build #2 main program): The `TypeCheckShimGenerator` now reuses _all_
.ngtypecheck `ts.SourceFile` shims from build #1's type-check program in
the construction of build #2's main program. Some of the contents of
these files might be stale (if a component's template changed, for
example), but wholesale reuse here prevents unnecessary changes in the
contents of the program at this point and makes TypeScript's job a lot
easier.
4. (Build #2 type-check program): For those input files which have not
"logically changed" (meaning components within are semantically the same
as they were before), the compiler will re-use the type-check file
metadata from build #1, and _not_ generate a new .ngtypecheck shim.
For components which have logically changed or where the previous
.ngtypecheck contents cannot otherwise be reused, code generation happens
as before.
PR Close#36211
As a performance optimization, this commit splits the single
__ngtypecheck__.ts file which was previously added to the user's program as
a container for all template type-checking code into multiple .ngtypecheck
shim files, one for each original file in the user's program.
In larger applications, the generation, parsing, and checking of this single
type-checking file was a huge performance bottleneck, with the file often
exceeding 1 MB in text content. Particularly in incremental builds,
regenerating this single file for the entire application proved especially
expensive.
This commit introduces a new strategy for template type-checking code which
makes use of a new interface, the `TypeCheckingProgramStrategy`. This
interface abstracts the process of creating a new `ts.Program` to type-check
a particular compilation, and allows the mechanism there to be kept separate
from the more complex logic around dealing with multiple .ngtypecheck files.
A new `TemplateTypeChecker` hosts that logic and interacts with the
`TypeCheckingProgramStrategy` to actually generate and return diagnostics.
The `TypeCheckContext` class, previously the workhorse of template type-
checking, is now solely focused on collecting and generating type-checking
file contents.
A side effect of implementing the new `TypeCheckingProgramStrategy` in this
way is that the API is designed to be suitable for use by the Angular
Language Service as well. The LS also needs to type-check components, but
has its own method for constructing a `ts.Program` with type-checking code.
Note that this commit does not make the actual checking of templates at all
_incremental_ just yet. That will happen in a future commit.
PR Close#36211
Shim generation was built on a lie.
Shims are files added to the program which aren't original files authored by
the user, but files authored effectively by the compiler. These fall into
two categories: files which will be generated (like the .ngfactory shims we
generate for View Engine compatibility) as well as files used internally in
compilation (like the __ng_typecheck__.ts file).
Previously, shim generation was driven by the `rootFiles` passed to the
compiler as input. These are effectively the `files` listed in the
`tsconfig.json`. Each shim generator (e.g. the `FactoryGenerator`) would
examine the `rootFiles` and produce a list of shim file names which it would
be responsible for generating. These names would then be added to the
`rootFiles` when the program was created.
The fatal flaw here is that `rootFiles` does not always account for all of
the files in the program. In fact, it's quite rare that it does. Users don't
typically specify every file directly in `files`. Instead, they rely on
TypeScript, during program creation, starting with a few root files and
transitively discovering all of the files in the program.
This happens, however, during `ts.createProgram`, which is too late to add
new files to the `rootFiles` list.
As a result, shim generation was only including shims for files actually
listed in the `tsconfig.json` file, and not for the transitive set of files
in the user's program as it should.
This commit completely rewrites shim generation to use a different technique
for adding files to the program, inspired by View Engine's shim generator.
In this new technique, as the program is being created and `ts.SourceFile`s
are being requested from the `NgCompilerHost`, shims for those files are
generated and a reference to them is patched onto the original file's
`ts.SourceFile.referencedFiles`. This causes TS to think that the original
file references the shim, and causes the shim to be included in the program.
The original `referencedFiles` array is saved and restored after program
creation, hiding this little hack from the rest of the system.
The new shim generation engine differentiates between two kinds of shims:
top-level shims (such as the flat module entrypoint file and
__ng_typecheck__.ts) and per-file shims such as ngfactory or ngsummary
files. The former are included via `rootFiles` as before, the latter are
included via the `referencedFiles` of their corresponding original files.
As a result of this change, shims are now correctly generated for all files
in the program, not just the ones named in `tsconfig.json`.
A few mitigating factors prevented this bug from being realized until now:
* in g3, `files` does include the transitive closure of files in the program
* in CLI apps, shims are not really used
This change also makes use of a novel technique for associating information
with source files: the use of an `NgExtension` `Symbol` to patch the
information directly onto the AST object. This is used in several
circumstances:
* For shims, metadata about a `ts.SourceFile`'s status as a shim and its
origins are held in the extension data.
* For original files, the original `referencedFiles` are stashed in the
extension data for later restoration.
The main benefit of this technique is a lot less bookkeeping around `Map`s
of `ts.SourceFile`s to various kinds of data, which need to be tracked/
invalidated as part of incremental builds.
This technique is based on designs used internally in the TypeScript
compiler and is serving as a prototype of this design in ngtsc. If it works
well, it could have benefits across the rest of the compiler.
PR Close#36211
The compiler needs to track the dependencies of a component, including any
NgModules which happen to be present in a component's scope. If an upstream
NgModule changes, any downstream components need to have their templates
re-compiled and re-typechecked.
Previously, the compiler handled this well for the A -> B -> C case where
module A imports module B which re-exports module C. However, it fell apart
in the A -> B -> C -> D case, because previously tracking focused on changes
to components/directives in the scope, and not NgModules specifically.
This commit introduces logic to track which NgModules contributed to a given
scope, and treat them as dependencies of any components within.
This logic also contains a bug, which is intentional for now. It
purposefully does not track transitive dependencies of the NgModules which
contribute to a scope. If it did, using the current dependency system, this
would treat all components and directives (even those not exported into the
scope) as dependencies, causing a major performance bottleneck. Only those
dependencies which contributed to the module's export scope should be
considered, but the current system is incapable of making this distinction.
This will be fixed at a later date.
PR Close#36211
Add a mechanism to replace file contents for a specific file. This
allows us to write custom test scenarios in code without modifying the
test project.
Since we are no longer mocking the language service host, the file
overwrite needs to happen via the project service.
Project service manages a set of script infos, and overwriting the files
is a matter of updating the relevant script infos.
Note that the actual project service is wrapped inside a Mock Service.
Tests should not have direct access to the project service. All
manipulations should take place via the Mock Service.
The MockService provides a `reset()` method to undo temporary overwrites
after each test.
PR Close#36923
The legacy HTTP package was deprecated in v5 with the launch of
@angular/common/http. The legacy package hasn't been published
since v7, and will therefore not include a migration.
PR Close#27038
Remove TypeScript 3.6 and 3.7 support from Angular along with tests that
ensure those TS versions work.
BREAKING CHANGE: typescript 3.6 and 3.7 are no longer supported, please
update to typescript 3.8
PR Close#36329
This commit fixes 2 separate issues related to root nodes retrieval from
embedded views with `<ng-content>`:
1) we did not account for the case where there were no projectable nodes
for a given `<ng-content>`;
2) we did not account for the case where projectable nodes for a given
`<ng-content>` were represented as an array of native nodes (happens in
the case of dynamically created components with projectable nodes);
Fixes#35967
PR Close#36051
The `elements` tests were disabled on Saucelabs, because they were failing on IE10. The problem was that we were loading an es2015 file from npm directly, causing a syntax error. These changes transpile the file to es5.
PR Close#36929
Parse Angular compiler options in Angular language service.
In View Engine, only TypeScript compiler options are read, Angular
compiler options are not. With Ivy, there could be different modes of
compilation, most notably how strict the templates should be checked.
This commit makes the behavior of language service consistent with the
Ivy compiler.
PR Close#36922
Previously we were passing a string form of the value to pluralize
to the `getLocalePluralCase()` function that is extracted from the
locale data. But some locales have functions that rely upon this
value being a number not a string.
Now we convert the value to a number before passing it to the
locale data function.
Fixes#36888
PR Close#36901
The `getLocation()` method was not working as there were typos in the
properties it was reading. This was not picked up because there were
neither typings for these properties nor unit tests to check it worked.
PR Close#36853
Previously, the behavior of the `minLength` and `maxLength` validators
caused confusion, as they appeared to work with numeric values but
did not in fact produce consistent results. This commit fixes the issue
by skipping validation altogether when a numeric value is used.
BREAKING CHANGES:
* The `minLength` and `maxLength` validators now verify that a value has
numeric `length` property and invoke validation only if that's the case.
Previously, falsey values without the length property (such as `0` or
`false` values) were triggering validation errors. If your code relies on
the old behavior, you can include other validators such as [min][1] or
[requiredTrue][2] to the list of validators for a particular field.
[1]: https://angular.io/api/forms/Validators#min
[2]: https://angular.io/api/forms/Validators#requiredTrueCloses#35591
PR Close#36157
This commit adds a method `overrideInlineTemplate` to the
`MockTypescriptHost`. This allows us to override an inline template
in a Component without changing the TypeScript parts. This methods works
in a similar way as `MockTypescriptHost.override()`, which is used for
overriding external template.
PR Close#36890
This function needs to deduplicate the paths that are found from the
paths mappings. Previously this deduplication was not linear and also
called the expensive `relative()` function many times.
This commit, suggested by @JoostK, reduces the complexity of the deduplication
by using a tree structure built from the segments of each path.
PR Close#36881
Previously the `basePaths` were computed when the finder was instantiated.
This was a waste of effort in the case that the targeted entry-point is already
processed.
This change makes the computation of `basePaths` lazy, so that the work is
only done if they are actually needed.
Fixes#36874
PR Close#36881
In TS 3.9 the compiler will start to wrap ES2015 classes in an IIFE to help with
tree-shaking when the class has "associated" statements.
E.g.
```ts
let PlatformLocation = /** @class */ (() => {
...
class PlatformLocation {
}
...
return PlatformLocation;
})();
```
This commit updates `Esm2015ReflectionHost` to support this format.
PR Close#36884
This commit adds a new mock host for testing the ivy language service.
Unlike the existing mock_host which mocks the LanguageServiceHost, the
Ivy mock host mocks just the filesystem interface, aka ts.ServerHost.
This is because Ivy language service requires an actual Project to
perform operations like adding synthetic typecheck files to the project,
and by extension, to the ts.Program. These requirements make the existing
mock host unsuitable to be reused.
This new testing structure also improves test performance, because the
old mock host copies (it actually creates symlinks, but still that's
relatively expensive due to the sheer number of files involved) all
@angular/* packages along with the typescript package to a temporary
node_modules directory. This is done every time setup() is called.
Instead, this new mock host just loads them from a pre-determined path
in Bazel runfiles.
PR Close#36879
Changes the Ivy unknown element/property messages from being logged with `console.warn` to `console.error`. This should make them a bit more visible without breaking existing apps. Furthermore, a lot of folks filter out warning messages in the dev tools' console, whereas errors are usually still shown.
BREAKING CHANGE:
Warnings about unknown elements are now logged as errors. This won't break your app, but it may trip up tools that expect nothing to be logged via `console.error`.
Fixes#35699.
PR Close#36399
This change aligns behavior for resolvers which return EMPTY. Currently EMPTY resolvers have inconsistent behavior:
- One resolver that returns EMPTY => won't navigate and just ends on ResolveStart router event.
- Two resolvers where both return EMPTY => throws "Error: Uncaught (in promise): EmptyError: no elements in sequence"
- Two resolvers where one returns a value and the other one returns EMPTY => Navigates successfully.
With this change any EMPTY resolver will cancel navigation.
BREAKING CHANGE: Any resolver which return EMPTY will cancel navigation.
If you want to allow the navigation to continue, you will need to update the resolvers to emit
some value, (i.e. defaultIfEmpty(...), of(...), etc).
PR Close#24195
PR Close#24621
This commit makes the test project a filegroup so that it could be
shared with the Ivy tests.
Also removed `project/foo.ts` since it is no longer used.
PR Close#36865
This commit adds a new entry point for the Ivy version of language
service. The entry point is just a shell for now, implementation will be
added in subsequent PRs.
The Ivy version of language service could be loaded from the NPM package
via `require(@angular/language-service/bundles/ivy.umd.js)`
PR Close#36864
Previously the `AsyncLocker` was configured to only wait
50x500ms before timing out. This is 25secs, which is often
less than a normal run of ngcc, so the chance of a timeout
flake was quite high.
The default is now 500x500ms, which is 250secs. If this is
too high for some projects then it can be changed via the
`ngcc.config.js` project file.
PR Close#36838
The commit adds support to the ngcc.config.js file for setting the
`retryAttempts` and `retryDelay` options for the `AsyncLocker`.
An integration test adds a new check for a timeout and actually uses the
ngcc.config.js to reduce the timeout time to prevent the test from taking
too long to complete.
PR Close#36838
Strictly this method only returns config for packages. So this commit
renames it to `getPackageConfig()`, which frees us up to add other
"getXxxxConfig()` methods later.
PR Close#36838
This test is basically duplicated (and slightly enhanced) in the
following test. So it is superfluous. (I suspect it was the result
of a broken rebase.)
PR Close#36838
When ngcc fails due to a timeout waiting for another process
to complete, it was not failing with a unique exit code, so that it
was not possible to know if the process can be restarted; compared to
ngcc failing for some more fatal reason.
Now if ngcc exits because of a timeout, the exit code will be 177.
PR Close#36838
When ngcc is having to pause and wait for another process
it provides a message to the user. This commit adds the extra
information about how to remove the lockfile if desired, since
this message is not shown if you Ctrl-C out of the process before
the timeout period ends.
PR Close#36838
Previously only one translation file per locale could be loaded.
Now the user can specify multiple files per locale, and the translations
from each of these files will be merged together by message id.
The merging is on a first-wins approach. So if to you have three files
to be merged:
```
['a.xlf', 'b.xmb', 'c.json']
```
Then any message from `a.xlf` will be used rather than a message from `b.xmb`
or `c.json` and so on. In practice this means that you should put the files
in order of most important first, with "fallback" translations later.
PR Close#36792
This commit introduces `Diagnostics.merge(other)` which will take the messages from
`other` and append them to the messages of `this`.
The translation loader is updated to use this new method.
PR Close#36792
Previously the `missingTranslation` option had to be checked before calling
`warn` or `error` on the `diagnostics` object.
Now this boilerplate is hidden inside the `Diagnostics.add()` method, which
will open it up to being used for other conditional diagnostics.
PR Close#36792
The Angular ServiceWorker always uses a copy of the request without
headers for caching assets (in order to avoid issues with opaque
responses). Therefore, it was previously not possible to retrieve
resources from the cache if the response contained [Vary](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Vary) headers.
In addition to that, `Vary` headers do not work in all browsers (or work
differently) and may not work as intended with ServiceWorker caches. See
[this article](https://www.smashingmagazine.com/2017/11/understanding-vary-header) and the linked resources for more info.
This commit avoids the aforementioned issues by making sure the Angular
ServiceWorker always sets the `ignoreVary` option passed to
[Cache#match()](https://developer.mozilla.org/en-US/docs/Web/API/Cache/match) to `true`. This allows the ServiceWorker to correctly
retrieve cached responses with `Vary` headers, which was previously not
possible.
Fixes#36638
BREAKING CHANGE:
Previously, [Vary](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Vary)
headers would be taken into account when retrieving resources from the
cache, completely preventing the retrieval of cached assets (due to
ServiceWorker implementation details) and leading to unpredictable
behavior due to inconsistent/buggy implementations in different
browsers.
Now, `Vary` headers are ignored when retrieving resources from the
ServiceWorker caches, which can result in resources being retrieved even
when their headers are different. If your application needs to
differentiate its responses based on request headers, please make sure
the Angular ServiceWorker is [configured](https://angular.io/guide/service-worker-config)
to avoid caching the affected resources.
PR Close#34663
Previously it was not possible to provide `CacheQueryOptions` ([MDN](https://developer.mozilla.org/en-US/docs/Web/API/Cache)) for querying the Cache.
This commit introduces a new parameter called `cacheQueryOptions` for `DataGroup` and `AssetGroup`.
Currently only `ignoreSearch` is supported as `ignoreVary` and `ignoreMethod` would require using
the complete Request object for matching which is not possible with the current implementation.
Closes#28443
PR Close#34663
`AsyncPipe` only uses `WrappedValue` when the latest value from the `Promise` or `Observable` is different from the previous one. This is already enough to trigger change detection so the `WrappedValue` is not necessary.
Fixes#29927
BREAKING CHANGE:
This change could result in ExpressionChangedAfterItHasBeenChecked errors that
were not detected before. The error could previously have gone undetected
because two WrappedValues are considered "equal" in all cases for the purposes
of the check, even if their respective unwrapped values are not.
Additionally, `[val]=(observable | async).someProperty` will no longer
trigger change detection if the value of `someProperty` is identical to
the value in the previous emit. If you need to force change detection,
either update the binding to use an object whose reference changes or
subscribe to the observable and call markForCheck as needed.
PR Close#36633
Only refresh transplanted views at the insertion location in Ivy.
Previously, Ivy would check transplanted views at both the insertion and
declaration points. This is achieved by adding a marker to the insertion
tree when we encounter a transplanted view that needs to be refreshed at
its declaration. We use this marker as an extra indication that we still
need to descend and refresh those transplanted views at their insertion
locations even if the insertion view and/or its parents are not dirty.
This change fixes several issues:
* Transplanted views refreshed twice if both insertion and declaration
are dirty. This could be an error if the insertion component changes
result in data not being available to the transplanted view because it
is slated to be removed.
* CheckAlways transplanted views not refreshed if shielded by
non-dirty OnPush (fixes#35400)
* Transplanted views still refreshed when insertion tree is detached
(fixes#21324)
PR Close#35968
Now that `ngcc/src/ngcc_options` imports `FileWriter` type, there is a
circular dependency detected by the `ts-circular-deps:check` lint check:
```
ngcc/src/ngcc_options.ts
→ ngcc/src/writing/file_writer.ts
→ ngcc/src/packages/entry_point_bundle.ts
→ ngcc/src/ngcc_options.ts
```
This commit moves the `PathMappings` type (and related helpers) to a
separate file to avoid the circular dependency.
NOTE:
The circular dependency was only with taking types into account. There
was no circular dependency for the actual (JS) code.
PR Close#36626
When running in parallel mode, worker processes forward errors thrown
during task processing to the master process, which in turn exits with
an error.
However, there are cases where the error is not directly related to
processing the entry-point. One such case is when there is not enough
memory (for example, due to all the other tasks being processed
simultaneously).
Previously, an `ENOMEM` error thrown on a worker process would propagate
to the master process, eventually causing ngcc to exit with an error.
Example failure: https://circleci.com/gh/angular/angular/682198
This commit improves handling of these low-memory situations by
detecting `ENOMEM` errors and killing the worker process, thus allowing
the master process to decide how to handle that. The master process will
put the task back into the tasks queue and continue processing tasks
with the rest of the worker processes (and thus with lower memory
pressure).
PR Close#36626
Previously, when the last worker process crashed, the master process
would try to re-spawn it indefinitely. This could lead to an infinite
loop (if for some reason the worker process kept crashing).
This commit avoids this by limiting the number of re-spawn attempts to
3, after which ngcc will exit with an error.
PR Close#36626
Previously, when running in parallel mode and a worker process crashed
while processing a task, it was not possible for ngcc to continue
without risking ending up with a corrupted entry-point and therefore it
exited with an error. This, for example, could happen when a worker
process received a `SIGKILL` signal, which was frequently observed in CI
environments. This was probably the result of Docker killing processes
due to increased memory pressure.
One factor that amplifies the problem under Docker (which is often used
in CI) is that it is not possible to distinguish between the available
CPU cores on the host machine and the ones made available to Docker
containers, thus resulting in ngcc spawning too many worker processes.
This commit addresses these issues in the following ways:
1. We take advantage of the fact that files are written to disk only
after an entry-point has been fully analyzed/compiled. The master
process can now determine whether a worker process has not yet
started writing files to disk (even if it was in the middle of
processing a task) and just put the task back into the tasks queue if
the worker process crashes.
2. The master process keeps track of the transformed files that a worker
process will attempt to write to disk. If the worker process crashes
while writing files, the master process can revert any changes and
put the task back into the tasks queue (without risking corruption).
3. When a worker process crashes while processing a task (which can be a
result of increased memory pressure or too many worker processes),
the master process will not try to re-spawn it. This way the number
or worker processes is gradually adjusted to a level that can be
accomodated by the system's resources.
Examples of ngcc being able to recover after a worker process crashed:
- While idling: https://circleci.com/gh/angular/angular/682197
- While compiling: https://circleci.com/gh/angular/angular/682209
- While writing files: https://circleci.com/gh/angular/angular/682267
Jira issue: [FW-2008](https://angular-team.atlassian.net/browse/FW-2008)
Fixes#36278
PR Close#36626
This commit adds a `revertFile()` method to `FileWriter`, which can
revert a transformed file (and its backup - if any) written by the
`FileWriter`.
In a subsequent commit, this will be used to allow ngcc to recover
when a worker process crashes in the middle of processing a task.
PR Close#36626
Paul Gschwendtner
Igor Minar
Pete Bacon Darwin
Misko Hevery
Alex Rickabaugh
Keen Yee Liau
Adam Plumer
Andrew Scott
Pawel Kozlowski
crisbeto
Walter Werner SCHNEIDER
Sonu Kapoor
Martin Sikora
Aleksander
Maximilian Koeller
George Kalpakas