angular/packages/compiler-cli/linker
Kristiyan Kostadinov f6da091228 refactor(compiler): introduce compiler infrastructure for input transforms (#50225)
Adds the necessary compiler changes to support input transform functions. The compiler output has changed in the following ways:

### Directive handler
The directive handler now extracts a reference to the input transform function and it resolves the type of its first parameter. It also asserts that the type can be referenced in the compiled output and that it doesn't clash with any pre-existing `ngAcceptInputType_` members.

### .d.ts
In the generated declaration files the compiler now inserts an `ngAcceptInputType_` member for each input with a `transform` function. The member's type corresponds to the type of the first parameter of the function, e.g.

```typescript
// foo.directive.ts
@Directive()
export class Foo {
  @Input({transform: (incomingValue: string) => parseInt(incomingValue)}) value: number;
}

// foo.directive.d.ts
export class Foo {
  value: number;
  static ngAcceptInputType_value: string;
}
```

### Type check block
If an input has `transform` function, the TCB will use the type of its first parameter for the setter type. This uses the same infrastructure as the `ngAcceptInputType_` members.

### Directive declaration
The generated runtime directive declaration call now includes the `transform` function in the `inputs` map, if the input is being transformed. The function will be picked up by the runtime in the next commit to do the actual transformation.

```typescript
// foo.directive.ts
@Directive()
export class Foo {
  @Input({transform: (incomingValue: string) => parseInt(incomingValue)}) value: number;
}

// foo.directive.js
export class Foo {
  ɵdir = ɵɵdefineDirective({
    inputs: {
      value: ['value', 'value', incomingValue => parseInt(incomingValue)]
    }
  });
}
```

PR Close #50225
2023-05-22 14:48:02 +00:00
..
babel refactor: update compiler-cli babel linker to be ESM only (#48521) 2022-12-19 19:50:43 +00:00
src refactor(compiler): introduce compiler infrastructure for input transforms (#50225) 2023-05-22 14:48:02 +00:00
test build: ensure bootstrap transitive runfiles are made available (#48521) 2022-12-19 19:50:41 +00:00
BUILD.bazel refactor(compiler-cli): support external template source-mapping when linking (#40237) 2021-01-07 13:12:53 -08:00
index.ts refactor(compiler-cli): implement ɵɵngDeclareNgModule and ɵɵngDeclareInjector (#41080) 2021-03-15 13:26:51 -07:00
README.md refactor(compiler-cli): linker - add Babel plugin, FileLinker and initial PartialLinkers (#39116) 2020-10-19 11:23:45 -07:00

Angular Linker

This package contains a FileLinker and supporting code to be able to "link" partial declarations of components, directives, etc in libraries to produce the full definitions.

The partial declaration format allows library packages to be published to npm without exposing the underlying Ivy instructions.

The tooling here allows application build tools (e.g. CLI) to produce fully compiled components, directives, etc at the point when the application is bundled. These linked files can be cached outside node_modules so it does not suffer from problems of mutating packages in node_modules.

Generally this tooling will be wrapped in a transpiler specific plugin, such as the provided Babel plugin.

Unit Testing

The unit tests are built and run using Bazel:

yarn bazel test //packages/compiler-cli/linker/test