fix(form-core): fix DeepValue from record values being wrong

[LeCarbonator]

Closes #1551

This PR fixes a wrong intersection that occurs when iterating over template strings (such as records).
The issue arose because of TypeScript inferring the following:

type DeepKeysExample = 'records' | `records.${string}` | `records.${string}.name`

type GetValueFrom = 'records.foo.name'
// This matches both `records.${string}.name` as well as `records.${string}`.

// Generated DeepValue: 
// { name: string } & string

// With PR fix:
// string

Important

TypeScript has a limitation with template string types. Nested records are not yet safe. Example below:

type NestedRecord = {
  numberRecord: Record<string, number>
  objectRecord: Record<string, { age: number }>
}

type RecordWrapper = {
  records: Record<string, NestedRecord>
}

type Test1 = DeepValue<RecordWrapper, 'records.foo.numberRecord.bar'>
// Type: NestedRecord & number
// `records.${'foo'}.numberRecord.${'bar'}`
// `records.${'foo.numberRecord.bar'}`

type Test2 = DeepValue<RecordWrapper, 'records.foo.objectRecord.bar'>
// Type: NestedRecord & { age: number }
// `records.${'foo'}.objectRecord.${'bar'}`
// `records.${'foo.objectRecord.bar'}`

type Test3 = DeepValue<RecordWrapper, 'records.foo.objectRecord.bar.age'>
// Type: number
// `records.${'foo'}.objectRecord.${'bar'}.age`

[nx-cloud]

View your CI Pipeline Execution ↗ for commit 07b3377.

Command	Status	Duration	Result
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---

☁️ Nx Cloud last updated this comment at 2025-06-05 16:15:23 UTC

[pkg-pr-new]

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commit: 07b3377

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.24%. Comparing base (77acb33) to head (07b3377).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1558   +/-   ##
=======================================
  Coverage   89.24%   89.24%           
=======================================
  Files          31       31           
  Lines        1432     1432           
  Branches      366      366           
=======================================
  Hits         1278     1278           
  Misses        137      137           
  Partials       17       17           

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[binajmen]

thank you for fixing this! is there a timeline on when it will be included in a release? 👀

[LeCarbonator]

@binajmen Well, the main issue is that this isn't really a fix. This PR has been a bit stale because of that ... but I'm not sure there will be a convenient solution that doesn't need reworking all of the DeepKeys types