Output migration transforms eventEmitter.emit() into invalid output.emit() #58650
Description
Which @angular/* package(s) are the source of the bug?
core
Is this a regression?
Yes
Description
The output migration transforms:
@Output() eventEmitter = new EventEmitter<string>();
// later
eventEmitter.emit();into
eventEmitter = output<string>();
// later
eventEmitter.emit();But the value is mandatory in the output.emit signature, so the application breaks.
The migration could generate emit(undefined) in that case, or add a TODO or only treat this in with the --best-effort-mode option.
To repro, in the following Stackblitz, run:
ng g @angular/core:signals --migrations=outputs --path=./ --no-best-effort-mode
Please provide a link to a minimal reproduction of the bug
https://stackblitz.com/edit/stackblitz-starters-h5tea2?file=src%2Fmain.ts
Please provide the exception or error you saw
✘ [ERROR] TS2554: Expected 1 arguments, but got 0. [plugin angular-compiler]
src/main.ts:18:22:
18 │ this.eventEmitter.emit();
╵ ~~~~
An argument for 'value' was not provided.
node_modules/@angular/core/index.d.ts:8288:9:
8288 │ emit(value: T): void;
Please provide the environment you discovered this bug in (run ng version)
Angular CLI: 19.0.0-rc.1
Node: 18.20.3
Package Manager: npm 10.2.3
OS: linux x64
Angular: 19.0.0-rc.1
... animations, cli, common, compiler, compiler-cli, core, forms
... platform-browser, router
Package Version
---------------------------------------------------------
@angular-devkit/architect 0.1900.0-rc.1
@angular-devkit/build-angular 19.0.0-rc.1
@angular-devkit/core 19.0.0-rc.1
@angular-devkit/schematics 19.0.0-rc.1
@schematics/angular 19.0.0-rc.1
rxjs 7.8.1
typescript 5.5.4
zone.js 0.14.10
Anything else?
No response