Signal Forms: parse errors are lost when parse() returns both value and errors #67170
Description
Which @angular/* package(s) are the source of the bug?
forms
Is this a regression?
Yes
Description
In Signal Forms, parse errors can be dropped when a custom control uses transformedValue and parse() returns both a parsed value and errors in the same result.
This affects scenarios like validation during parsing (for example returning a numeric value but also emitting a max/min style parse error).
If parse() returns { value, errors }, both should be preserved. In rc.0 the value updates, but errors are cleared and do not appear on field.errors().
To repro, create a custom FormValueControl<number | null> using transformedValue with:
parse: (raw) => {
const value = Number(raw);
if (Number.isNaN(value)) return { errors: [{ kind: 'parse' }] };
if (value > 10) return { value, errors: [maxError(10)] };
return { value };
}
When entering 11, the field value updates, but field.errors() is empty (expected a max error).
Please provide a link to a minimal reproduction of the bug
No response
Please provide the exception or error you saw
Please provide the environment you discovered this bug in (run ng version)
Angular CLI : 21.2.0-rc.0
Angular : 21.2.0-rc.0
Node.js : 22.22.0
Package Manager : npm 10.9.0
Operating System : darwin arm64
┌───────────────────────────┬───────────────────┬───────────────────┐
│ Package │ Installed Version │ Requested Version │
├───────────────────────────┼───────────────────┼───────────────────┤
│ @angular/build │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ @angular/cli │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ @angular/common │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ @angular/compiler │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ @angular/compiler-cli │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ @angular/core │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ @angular/forms │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ @angular/localize │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ @angular/platform-browser │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ @angular/router │ 21.2.0-rc.0 │ 21.2.0-rc.0 │
│ rxjs │ 7.8.2 │ 7.8.2 │
│ typescript │ 5.9.3 │ 5.9.3 │
│ vitest │ 4.0.18 │ 4.0.18 │
Anything else?
This was working in next.3