There are two places in the ngcc processing where it needs to load the
content of a file given by a general path:
* when determining the format of an entry-point.
To do this ngcc uses the value of the relevant property in package.json.
But in the case of `main` it must parse the contents of the entry-point
file to decide whether the format is UMD or CommonJS.
* when parsing the source files for dependencies to determine the order in
which compilation must occur. The relative imports in each file are parsed
and followed recursively, looking for external imports.
Previously, we naively assumed that the path would match the file name exactly.
But actually we must consider the standard module resolution conventions.
E.g. the extension (.js) may be missing, or the path may refer to a directory
containing an index.js file.
This commit fixes both places.
This commit now requires the `DependencyHost` instances to check
the existence of more files than before (at worst all the different possible
post-fixes). This should not create a significant performance reduction for
ngcc. Since the results of the checks will be cached, and similar work is
done inside the TS compiler, so what we lose in doing it here, is saved later
in the processing. The main performance loss would be where there are lots
of files that need to be parsed for dependencies that do not end up being
processed by TS. But compared to the main ngcc processing this dependency
parsing is a small proportion of the work done and so should not impact
much on the overall performance of ngcc.
// FW-1444
PR Close#31509
When determining if a `main` path points to a UMD or CommonJS
format, the contents of the file need to be loaded and parsed.
Previously, it was assumed that the path referred to the exact filename,
but did not account for normal module resolution semantics, where the
path may be missing an extension or refer to a directory containing an
`index.js` file.
// FW-1444
PR Close#31509
Non-wild-card path-mappings were not being matched correctly.
Further path-mapped secondary entry-points that
were imported from the associated primary entry-point were not
being martched correctly.
Fixes#31274
PR Close#31450
If an entry-point has missing dependencies then it cannot be
processed and is marked as invalid. Similarly, if an entry-point
has dependencies that have been marked as invalid then that
entry-point too is invalid. In all these cases, ngcc should quietly
ignore these entry-points and continue processing what it can.
Previously, if an entry-point had more than one entry-point that
was transitively invalid then ngcc was crashing rather than
ignoring the entry-point.
PR Close#31276
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
If an entry-point has a missing dependency then all the entry-points
that would have pointed to that dependency are also removed from
the dependency graph.
Previously we were still processing the dependencies of an entry-point
even if it had already been removed from the graph because it depended
upon a missing dependency that had previously been removed due to another
entry-point depending upon it.
This caused the dependency processing to crash rather than gracefully
logging and handling the missing invalid entry-point.
Fixes#29624
PR Close#30270
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
Pete Bacon Darwin
Matias Niemelä
Alan