When the compiler needs to convert a type reference to a value
expression, it may encounter a type that refers to a namespaced symbol.
Such namespaces need to be handled specially as there's various forms
available. Consider a namespace named "ns":
1. One can refer to a namespace by itself: `ns`. A namespace is only
allowed to be used in a type position if it has been merged with a
class, but even if this is the case it may not be possible to convert
that type into a value expression depending on the import form. More
on this later (case a below)
2. One can refer to a type within the namespace: `ns.Foo`. An import
needs to be generated to `ns`, from which the `Foo` property can then
be read.
3. One can refer to a type in a nested namespace within `ns`:
`ns.Foo.Bar` and possibly even deeper nested. The value
representation is similar to case 2, but includes additional property
accesses.
The exact strategy of how to deal with these cases depends on the type
of import used. There's two flavors available:
a. A namespaced import like `import * as ns from 'ns';` that creates
a local namespace that is irrelevant to the import that needs to be
generated (as said import would be used instead of the original
import).
If the local namespace "ns" itself is referred to in a type position,
it is invalid to convert it into a value expression. Some JavaScript
libraries publish a value as default export using `export = MyClass;`
syntax, however it is illegal to refer to that value using "ns".
Consequently, such usage in a type position *must* be accompanied by
an `@Inject` decorator to provide an explicit token.
b. An explicit namespace declaration within a module, that can be
imported using a named import like `import {ns} from 'ns';` where the
"ns" module declares a namespace using `declare namespace ns {}`.
In this case, it's the namespace itself that needs to be imported,
after which any qualified references into the namespace are converted
into property accesses.
Before this change, support for namespaces in the type-to-value
conversion was limited and only worked correctly for a single qualified
name using a namespace import (case 2a). All other cases were either
producing incorrect code or would crash the compiler (case 1a).
Crashing the compiler is not desirable as it does not indicate where
the issue is. Moreover, the result of a type-to-value conversion is
irrelevant when an explicit injection token is provided using `@Inject`,
so referring to a namespace in a type position (case 1) could still be
valid.
This commit introduces logic to the type-to-value conversion to be able
to properly deal with all type references to namespaced symbols.
Fixes#36006
Resolves FW-1995
PR Close#36106
The ReflectionHost supports enumeration of constructor parameters, and one
piece of information it returns describes the origin of the parameter's
type. Parameter types come in two flavors: local (the type is not imported
from anywhere) or non-local (the type comes via an import).
ngcc incorrectly classified all type parameters as 'local', because in the
source files that ngcc processes the type parameter is a real ts.Identifer.
However, that identifier may still have come from an import and thus might
be non-local.
This commit changes ngcc's ReflectionHost(s) to properly recognize and
report these non-local type references.
Fixes#33677
PR Close#33901
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
JoostK
Pete Bacon Darwin
Alex Rickabaugh