One of the compiler's tasks is to enumerate the exports of a given ES
module. This can happen for example to resolve `foo.bar` where `foo` is a
namespace import:
```typescript
import * as foo from './foo';
@NgModule({
directives: [foo.DIRECTIVES],
})
```
In this case, the compiler must enumerate the exports of `foo.ts` in order
to evaluate the expression `foo.DIRECTIVES`.
When this operation occurs under ngcc, it must deal with the different
module formats and types of exports that occur. In commonjs code, a problem
arises when certain exports are downleveled.
```typescript
export const DIRECTIVES = [
FooDir,
BarDir,
];
```
can be downleveled to:
```javascript
exports.DIRECTIVES = [
FooDir,
BarDir,
```
Previously, ngtsc and ngcc expected that any export would have an associated
`ts.Declaration` node. `export class`, `export function`, etc. all retain
`ts.Declaration`s even when downleveled. But the `export const` construct
above does not. Therefore, ngcc would not detect `DIRECTIVES` as an export
of `foo.ts`, and the evaluation of `foo.DIRECTIVES` would therefore fail.
To solve this problem, the core concept of an exported `Declaration`
according to the `ReflectionHost` API is split into a `ConcreteDeclaration`
which has a `ts.Declaration`, and an `InlineDeclaration` which instead has
a `ts.Expression`. Differentiating between these allows ngcc to return an
`InlineDeclaration` for `DIRECTIVES` and correctly keep track of this
export.
PR Close#32129
Previously we were relying upon the `.get()` method to return `undefined`
but it is clearer and safer to always check with `.has()` first.
PR Close#25445
In ES2015, classes could have been emitted as a variable declaration
initialized with a class expression. In certain situations, an intermediary
variable suffixed with `_1` is present such that the variable
declaration's initializer becomes a binary expression with its rhs being
the class expression, and its lhs being the identifier of the intermediate
variable. This structure was not recognized, resulting in such classes not
being considered as a class in `Esm2015ReflectionHost`.
As a consequence, the analysis of functions/methods that return a
`ModuleWithProviders` object did not take the methods of such classes into
account.
Another edge-case with such intermediate variable was that static
properties would not be considered as class members. A testcase was added
to prevent regressions.
Fixes#29078
PR Close#29119
In ESM5 code, static methods appear as property assignments onto the constructor
function. For example:
```
var MyClass = (function() {
function MyClass () {}
MyClass.staticMethod = function() {};
return MyClass;
})();
```
This commit teaches ngcc how to process these forms when searching
for `ModuleWithProviders` functions that need to be updated in the typings
files.
PR Close#29092