This PR updates Angular to compile with TypeScript 3.6 while retaining
compatibility with TS3.5. We achieve this by inserting several `as any`
casts for compatiblity around `ts.CompilerHost` APIs.
PR Close#32908
In ngcc's reflection host for UMD and CommonJS bundles, custom logic is
present to resolve import details of an identifier. However, this custom
logic is unable to resolve an import for an identifier inside of
declaration files, as such files use the regular ESM import syntax.
As a consequence of this limitation, ngtsc is unable to resolve
`ModuleWithProviders` imports that are declared in an external library.
In that situation, ngtsc determines the type of the actual `NgModule`
that is imported, by looking in the library's declaration files for the
generic type argument on `ModuleWithProviders`. In this process, ngtsc
resolves the import for the `ModuleWithProviders` identifier to verify
that it is indeed the `ModuleWithProviders` type from `@angular/core`.
So, when the UMD reflection host was in use this resolution would fail,
therefore no `NgModule` type could be detected.
This commit fixes the bug by using the regular import resolution logic
in addition to the custom resolution logic that is required for UMD
and CommonJS bundles.
Fixes#31791
PR Close#32619
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
