This commit adds support in the Angular monorepo and in the Angular
compiler(s) for TypeScript 3.8. All packages can now compile with
TS 3.8.
For most of the repo, only a handful few typings adjustments were needed:
* TS 3.8 has a new `CustomElementConstructor` DOM type, which enforces a
zero-argument constructor. The `NgElementConstructor` type previously
declared a required `injector` argument despite the fact that its
implementation allowed `injector` to be optional. The interface type was
updated to reflect the optionality of the argument.
* Certain error messages were changed, and expectations in tests were
updated as a result.
* tsserver (part of language server) now returns performance information in
responses, so test expectations were changed to only assert on the actual
body content of responses.
For compiler-cli and schematics (which use the TypeScript AST) a major
breaking change was the introduction of the export form:
```typescript
export * as foo from 'bar';
```
This is a `ts.NamespaceExport`, and the `exportClause` of a
`ts.ExportDeclaration` can now take this type as well as `ts.NamedExports`.
This broke a lot of places where `exportClause` was assumed to be
`ts.NamedExports`.
For the most part these breakages were in cases where it is not necessary
to handle the new `ts.NamedExports` anyway. ngtsc's design uses the
`ts.TypeChecker` APIs to understand syntax and so automatically supports the
new form of exports.
The View Engine compiler on the other hand extracts TS structures into
metadata.json files, and that format was not designed for namespaced
exports. As a result it will take a nontrivial amount of work if we want to
support such exports in View Engine. For now, these new exports are not
accounted for in metadata.json, and so using them in "folded" Angular
expressions will result in errors (probably claiming that the referenced
exported namespace doesn't exist).
Care was taken to only use TS APIs which are present in 3.7/3.6, as Angular
needs to remain compatible with these for the time being.
This commit does not update angular.io.
PR Close#35864
The compiler uses metadata to represent what it statically knows about
various expressions in a program. Occasionally, expressions in the program
for which metadata is extracted may contain sub-expressions which are not
representable in metadata. One such construct is an arrow function.
The compiler does not always need to understand such expressions completely.
For example, for a provider defined with `useValue`, the compiler does not
need to understand the value at all, only the outer provider definition. In
this case, the compiler employs a technique known as "expression lowering",
where it rewrites the provider expression into one that can be represented
in metadata. Chiefly, this involves extracting out the dynamic part (the
`useValue` expression) into an exported constant.
Lowering is applied through a heuristic, which considers the containing
statement as well as the field name of the expression.
Previously, this heuristic was not completely accurate in the case of
route definitions and the `loadChildren` field, which is lowered. If the
route definition using `loadChildren` existed inside a decorator invocation,
lowering was performed correctly. However, if it existed inside a standalone
variable declaration with an export keyword, the heuristic would conclude
that lowering was unnecessary. For ordinary providers this is true; however
the compiler attempts to fully understand the ROUTES token and thus even if
an array of routes is declared in an exported variable, any `loadChildren`
expressions within still need to be lowered.
This commit enables lowering of already exported variables under a limited
set of conditions (where the initializer expression is of a specific form).
This should enable the use of `loadChildren` in route definitions.
PR Close#30038
All errors for existing fields have been detected and suppressed with a
`!` assertion.
Issue/24571 is tracking proper clean up of those instances.
One-line change required in ivy/compilation.ts, because it appears that
the new syntax causes tsickle emitted node to no longer track their
original sourceFiles.
PR Close#24572
This adds compilation of @NgModule providers and imports into
ngInjectorDef statements in generated code. All @NgModule annotations
will be compiled and the @NgModule decorators removed from the
resultant js output.
All @Injectables will also be compiled in Ivy mode, and the decorator
removed.
PR Close#22458
* don't reexport symbols that the user already reexported
* never reexport symbols that are part of arguments of non simple function calls
Fixes#19883
PR Close#19884
This change is needed to prevent users’ builds from breaking.
If a user sets `fullTemlateTypeCheck` to true, we will
continue to check the templates even when `skipTemplateCodegen` is true
as well.
Related to #19906
PR Close#19909
- temporarily keeps the old sources under packages/tsc-wrapped
until the build scripts are changed to use compiler-cli everywhere.
- removes the compiler options `disableTransformerPipeline` that was introduced
in a previous beta of Angular 5, i.e. the transformer based compiler
is now always enabled.
PR Close#18966
With this commit the compiler will "lower" expressions into exported
variables for values the compiler does not need to know statically
in order to be able to generate a factory. For example:
```
providers: [{provider: 'token', useValue: calculated()}]
```
produced an error as the expression `calculated()` is not supported
by the compiler because `calculated` is not a
[known function](https://angular.io/guide/metadata#annotationsdecorators)
With this commit this is rewritten, during emit of the .js file, into
something like:
```
export var ɵ0 = calculated();
...
provdiers: [{provider: 'token', useValue: ɵ0}]
```
The compiler then will now generate a reference to the exported `ɵ0`
instead of failing to evaluate `calculated()`.
PR Close#18905
With this commit the compiler will "lower" expressions into exported
variables for values the compiler does not need to know statically
in order to be able to generate a factory. For example:
```
providers: [{provider: 'token', useValue: calculated()}]
```
produced an error as the expression `calculated()` is not supported
by the compiler because `calculated` is not a
[known function](https://angular.io/guide/metadata#annotationsdecorators)
With this commit this is rewritten, during emit of the .js file, into
something like:
```
export var ɵ0 = calculated();
...
provdiers: [{provider: 'token', useValue: ɵ0}]
```
The compiler then will now generate a reference to the exported `ɵ0`
instead of failing to evaluate `calculated()`.
PR Close#18905
The source map does not currently work with the transformer pipeline.
It will be re-enabled after TypeScript 2.4 is made the min version.
To revert to the former compiler, use the `disableTransformerPipeline` in
tsconfig.json:
```
{
"angularCompilerOptions": {
"disableTransformerPipeline": true
}
}
```
