
Previously, the `FileSystem` abstraction featured a `mkdir()` method. In `NodeJSFileSystem` (the default `FileSystem` implementation used in actual code), the method behaved similar to Node.js' `fs.mkdirSync()` (i.e. failing if any parent directory is missing or the directory exists already). In contrast, `MockFileSystem` (which is the basis or mock `FileSystem` implementations used in tests) implemented `mkdir()` as an alias to `ensureDir()`, which behaved more like Node.js' `fs.mkdirSync()` with the `recursive` option set to `true` (i.e. creating any missing parent directories and succeeding if the directory exists already). This commit fixes this inconsistency by removing the `mkdir()` method, which was not used anyway and only keeping `ensureDir()` (which is consistent across our different `FileSystem` implementations). PR Close #33237
Virtual file-system layer
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 supplied.
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 helper method,
getFileSystem()
. This is also used by a number of helper
methods 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 helper 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 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, it callsinitMockFileSystem()
for each OS to emulate.loadTestFiles()
- use this to add files and their contents to the mock file system for testing.loadStandardTestFiles()
- 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.