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refactor(typescript-types): Refine KeyPaths<T,O,F> logic

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This commit is contained in:
T. R. Bernstein
2025-07-17 23:46:04 +02:00
parent c3238a6847
commit 5461fc52b4
2 changed files with 36 additions and 27 deletions
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23
packages/typescript-types/src/key-paths.ts
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@@ -1,5 +1,7 @@
import type { If } from './if.js'
import type { IsEmptyString } from './is-empty-string.js'
import type { IsUndefined } from './is-undefined.js'
import type { Simplify } from './simplify.js'
import type { Assign } from './assign.js'
interface KeyPaths_Options {
@@ -20,15 +22,10 @@ type GetPrefixedKey<
type PrefixIfNot<Cond, Prefix, T> = If<Cond, T, Prefix | T>
type KeyPathOf<
Obj,
Key extends PropertyKey,
Options extends Required<KeyPaths_Options>,
Parent extends string,
Filter = never
> = Obj extends { [P in Key]: Record<PropertyKey, unknown> }
? PrefixIfNot<Options['leavesOnly'], Parent, KeyPathsOfStringKeys<Obj[Key], Options, Filter, Parent>>
: Parent
type KeyPathOf<Obj, Options extends Required<KeyPaths_Options>, Parent extends string, Filter = never> =
Obj extends Record<PropertyKey, unknown>
? PrefixIfNot<Options['leavesOnly'], Parent, KeyPathsOfStringKeys<Obj, Options, Filter, Parent>>
: If<IsUndefined<Obj>, never, Parent>
type KeyPathsOfStringKeys<
Obj extends object,
@@ -36,13 +33,13 @@ type KeyPathsOfStringKeys<
Filter,
Parent extends string = ''
> = {
[Key in keyof Obj & string]: [Filter] extends [Exclude<Filter, Obj[Key]>]
? KeyPathOf<Obj, Key, Options, GetPrefixedKey<Parent, Key, Options['separator']>, Filter>
: never
[Key in keyof Obj & string]: Obj[Key] extends Filter
? never
: KeyPathOf<Obj[Key], Options, GetPrefixedKey<Parent, Key, Options['separator']>, Filter>
}[keyof Obj & string]
export type KeyPaths<
Obj extends object,
Options extends KeyPaths_Options = {},
Filter = null | undefined
> = KeyPathsOfStringKeys<Obj, Assign<KeyPaths_Options, KeyPaths_DefaultOptions, Options>, Filter>
> = Simplify<KeyPathsOfStringKeys<Obj, Assign<KeyPaths_Options, KeyPaths_DefaultOptions, Options>, Filter>>

40
packages/typescript-types/test/key-paths.tst.ts
View File

@@ -4,7 +4,10 @@ import { expect } from 'tstyche'
interface ExampleObject {
nullvalue: null
simplevalue: string
optionalKey?: string
optionalKey?: {
nullvalue: null
simplevalue: string
}
unknownKey: unknown
neverKey: never
config: {
@@ -13,27 +16,36 @@ interface ExampleObject {
}
}
expect<KeyPaths<ExampleObject>>().type.toBe<'simplevalue' | 'config.simplevalue'>()
expect<KeyPaths<ExampleObject, {}, any>>().type.toBeAssignableTo<
'nullvalue' | 'simplevalue' | 'optionalKey' | 'config.nullvalue' | 'config.simplevalue'
>()
expect<KeyPaths<ExampleObject, {}, unknown>>().type.toBeAssignableTo<
'nullvalue' | 'simplevalue' | 'optionalKey' | 'config.nullvalue' | 'config.simplevalue'
expect<KeyPaths<ExampleObject>>().type.toBe<
'simplevalue' | 'optionalKey.simplevalue' | 'unknownKey' | 'config.simplevalue'
>()
expect<KeyPaths<ExampleObject, {}, any>>().type.toBeAssignableTo<never>()
expect<KeyPaths<ExampleObject, {}, unknown>>().type.toBeAssignableTo<never>()
expect<KeyPaths<ExampleObject, {}, never>>().type.toBe<
'nullvalue' | 'simplevalue' | 'optionalKey' | 'unknownKey' | 'config.nullvalue' | 'config.simplevalue'
| 'nullvalue'
| 'simplevalue'
| 'optionalKey.nullvalue'
| 'optionalKey.simplevalue'
| 'unknownKey'
| 'config.nullvalue'
| 'config.simplevalue'
>()
expect<KeyPaths<ExampleObject, {}, null>>().type.toBe<
'simplevalue' | 'optionalKey.simplevalue' | 'unknownKey' | 'config.simplevalue'
>()
expect<KeyPaths<ExampleObject, {}, string>>().type.toBe<
'nullvalue' | 'optionalKey.nullvalue' | 'unknownKey' | 'config.nullvalue'
>()
expect<KeyPaths<ExampleObject, { separator: '-' }>>().type.toBe<
'simplevalue' | 'optionalKey-simplevalue' | 'unknownKey' | 'config-simplevalue'
>()
expect<KeyPaths<ExampleObject, {}, null>>().type.toBe<'simplevalue' | 'optionalKey' | 'config.simplevalue'>()
expect<KeyPaths<ExampleObject, {}, string>>().type.toBe<'nullvalue' | 'config.nullvalue'>()
expect<KeyPaths<ExampleObject, { separator: '-' }>>().type.toBe<'simplevalue' | 'config-simplevalue'>()
expect<KeyPaths<ExampleObject, { leavesOnly: false }>>().type.toBe<
'simplevalue' | 'config' | 'neverKey' | 'config.simplevalue'
'simplevalue' | 'optionalKey' | 'optionalKey.simplevalue' | 'unknownKey' | 'config' | 'config.simplevalue'
>()
expect<KeyPaths<any, {}, string>>().type.toBeAssignableTo<never>()
expect<KeyPaths<any, {}, any>>().type.toBeAssignableTo<never>()
expect<KeyPaths<never, {}, any>>().type.toBeAssignableTo<never>()
expect<KeyPaths<never, {}, never>>().type.toBeAssignableTo<never>()
expect<KeyPaths<any, {}, never>>().type.toBe<unknown>()
expect<KeyPaths<any, {}, string>>().type.toBeAssignableTo<unknown>()