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
If a project has nested projects that contain node_modules folders
that get processed by ngcc, it can be confusing when the ngcc
version changes since the error message is very generic:
```
The ngcc compiler has changed since the last ngcc build.
Please completely remove `node_modules` and try again.
```
This commit augments the error message with the path of
the entry-point that failed so that it is more obvious which
node_modules folder to remove.
BREAKING CHANGE:
This commit removes the public export of `hasBeenProcessed()`.
This was exported to be availble to the CLI integration but was never
used. The change to the function signature is a breaking change in itself
so we remove the function altogether to simplify and lower the public
API surface going forward.
PR Close#32396
When profiling ngcc it is notable that a large amount of time
is spent dealing with an exception that is thrown (and handled
internally by fs) when checking the existence of a file.
We check file existence a lot in both finding entry-points
and when TS is compiling code. This commit adds a simple
cached `FileSystem`, which wraps a real `FileSystem` delegate.
This will reduce the number of calls through to `fs.exists()` and
`fs.readFile()` on the delegate.
Initial benchmarks indicate that the cache is miss to hit ratio
for `exists()` is about 2:1, which means that we save about 1/3
of the calls to `fs.existsSync()`.
Note that this implements a "non-expiring" cache, so it is not suitable
for a long lived `FileSystem`, where files may be modified externally.
The cache will be updated if a file is changed or moved via
calls to `FileSystem` methods but it will not be aware of changes
to the files system from outside the `FileSystem` service.
For ngcc we must create a new `FileSystem` service
for each run of `mainNgcc` and ensure that all file operations
(including TS compilation) use the `FileSystem` service.
This ensures that it is very unlikely that a file will change
externally during `mainNgcc` processing.
PR Close#30525
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
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
If `targetEntryPointPath` is provided to `mainNgcc` then we will now mark all
the `propertiesToConsider` for that entry-point if we determine that
it does not contain code that was compiled by Angular (for instance it has
no `...metadata.json` file).
The commit also renames `__modified_by_ngcc__` to `__processed_by_ivy_ngcc__`, since
there may be entry-points that are marked despite ngcc not actually compiling anything.
PR Close#29092
Now the public API does not contain internal types, such as `AbsoluteFsPath` and
`EntryPointJsonProperty`. Instead we just accept strings and then guard them in
`mainNgcc` as appropriate.
A new public API function (`hasBeenProcessed`) has been exported to allow programmatic
checking of the build marker when the package.json contents are already known.
PR Close#29092
George Kalpakas
Pete Bacon Darwin