Class RecordCore

The core Object functions

Since

v1.0.0

Index

Methods

assert buildErr entries is isNot keys omit onKey onKeyEqual onKeyNotEqual pick values

Methods

`Static`assert

assert(value: unknown): asserts value is Record<PropertyKey, unknown>
Asserts that the given value is an Record.
Parameters
- value: unknown
  The value to check.
Returns asserts value is Record<PropertyKey, unknown>
Throws
If the value is not an object.

Since
v1.0.0
- Defined in src/lib/RecordCore.mts:34

`Static`buildErr

buildErr(value: unknown): TypeError
Builds an type error Invalid object: ${JSON.stringify(value)}.
Parameters
- value: unknown
  The invalid value.
Returns TypeError
The created error.

Since
v1.0.0
- Defined in src/lib/RecordCore.mts:245

`Static`entries

entries<R extends object>(value: R): ObjectMappedArrayTuples<R>

Type-safe Object.entries() with overload for NonEmptyArray

Type Parameters

R extends object
The object shape

Parameters

value: R
The object shape to get the values from

Returns ObjectMappedArrayTuples<R>

Array of tuples with key and value

Example

const result1: NonEmptyReadonlyArray<['key', 'value']> = RecordCore.entries({key: 'value'} as const);
const result2: Array<['key', string]> = RecordCore.entries({key: 'value'});
const result3: Array<[string, string]> = RecordCore.entries<Record<string, string>>({key: 'value'});
const result4: [] = RecordCore.entries({});

Since

v1.0.0

`Static`is

is(value: unknown): value is Record<PropertyKey, unknown>
Checks if the given value is an Record.
Parameters
- value: unknown
  The value to check.
Returns value is Record<PropertyKey, unknown>
True if the value is an object; otherwise, false.

Since
v1.0.0
- Defined in src/lib/RecordCore.mts:14

`Static`isNot

isNot<T>(value: T): value is Exclude<T, Record<PropertyKey, unknown>>
Checks if the given value is not an Record.
Type Parameters
- T
Parameters
- value: T
  The value to check.
Returns value is Exclude<T, Record<PropertyKey, unknown>>
True if the value is not an object; otherwise, false.

Since
v1.0.0
- Defined in src/lib/RecordCore.mts:24

`Static`keys

keys<R extends object>(value: R): ObjectMappedArray<R, keyof R>
Type-safe Object.keys() with overload for NonEmptyArray
Type Parameters
- R extends object
  The object shape
Parameters
- value: R
  The object shape to get the values from
Returns ObjectMappedArray<R, keyof R>
Array of object keys
Example
```
const result1: NonEmptyReadonlyArray<'key'> = RecordCore.keys({key: 'value'} as const);
const result2: Array<'key'> = RecordCore.keys({key: 'value'});
const result3: Array<string> = RecordCore.keys<Record<string, string>>({key: 'value'});
const result4: [] = RecordCore.keys({});
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:52

`Static`omit

omit<K extends PropertyKey, T extends Partial<Record<K, unknown>>>(
keys: Iterable<K>,
data: T,
): Omit<T, K>
Omit function to omit keys from an object or use as map function to omit keys from an array
Type Parameters
- K extends PropertyKey
  Omit keys
- T extends Partial<Record<K, unknown>>
  Object type
Parameters
- keys: Iterable<K>
  to omit
- data: T
  to omit from (optional)
Returns Omit<T, K>
omitted object or map function
Example
```
type Data = {demo: string, value: number|null};
const data: Data = {demo: 'hello', value: null};
const output: Omit<Data, 'value'> = RecordCore.omit(['value'], data);
const dataArray: Data[] = [{demo: 'hello', value: null}];
const output: Omit<Data, 'demo'>[] = dataArray.map(RecordCore.omit(['demo']));
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:102
omit<K extends PropertyKey>(
keys: Iterable<K>,
): <T extends Partial<Record<K, unknown>>>(value: T) => Omit<T, K>
Omit function to omit keys from an object or use as map function to omit keys from an array
Type Parameters
- K extends PropertyKey
  Omit keys
Parameters
- keys: Iterable<K>
  to omit
Returns <T extends Partial<Record<K, unknown>>>(value: T) => Omit<T, K>
omitted object or map function
Example
```
type Data = {demo: string, value: number|null};
const data: Data = {demo: 'hello', value: null};
const output: Omit<Data, 'value'> = RecordCore.omit(['value'], data);
const dataArray: Data[] = [{demo: 'hello', value: null}];
const output: Omit<Data, 'demo'>[] = dataArray.map(RecordCore.omit(['demo']));
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:103

`Static`onKey

onKey<
    T extends any[]
    | Record<PropertyKey, any>,
    K extends string | number | symbol,
>(
    key: K,
): (target: T) => T[K]
Creates a function that selects a specific property value from an object.

Useful for use with arrays map function when extracting a single property from each object.
Type Parameters
- T extends any[] | Record<PropertyKey, any>
  Object target from which the property will be selected
- K extends string | number | symbol
  Property name in target that will be selected
Parameters
- key: K
  The property name to select
Returns (target: T) => T[K]
select value by key from the target
Example
```
const user1: User = {id: 1, name: 'Alice', role: 'admin', active: true};
const getName = ObjCore.onKey('name');
const output: string = getName(user1);
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:167
onKey<K extends PropertyKey>(
key: K,
): <T extends Record<K, any>>(target: T) => T[K]
Creates a function that selects a specific property value from an object.

Useful for use with arrays map function when extracting a single property from each object.
Type Parameters
- K extends PropertyKey
  Property name in target that will be selected
Parameters
- key: K
  The property name to select
Returns <T extends Record<K, any>>(target: T) => T[K]
select value by key from the target
Example
```
const user1: User = {id: 1, name: 'Alice', role: 'admin', active: true};
const getName = ObjCore.onKey('name');
const output: string = getName(user1);
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:168

`Static`onKeyEqual

onKeyEqual<
    T extends Record<PropertyKey, any>,
    K extends string | number | symbol,
>(
    key: K,
    value: T[K],
): (obj: T) => boolean
Creates a predicate function that checks whether a given object's property equals the specified value.

Supports both strictly typed object structures and looser records with optional properties.

Useful for filtering arrays of objects based on property values.
Type Parameters
- T extends Record<PropertyKey, any>
  The object type with known keys (strict overload).
- K extends string | number | symbol
  The key of the property to compare.
Parameters
- key: K
  The property name to compare.
- value: T[K]
  The value to match against.
Returns (obj: T) => boolean
A predicate for use with arrays of type T.
Example
```
// Strict object structure
const isAdmin = RecordCore.onKeyEqual<User, 'role'>('role', 'admin');
const admins = users.filter(isAdmin);
```
Example
```
// Loosely typed object
const isPublished = RecordCore.onKeyEqual('status', 'published');
const publishedPosts = posts.filter(isPublished);
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:200
onKeyEqual<V, K extends PropertyKey>(
key: K,
value: V,
): (obj: Partial<Record<K, V>>) => boolean
Creates a predicate function that checks whether a given object's property equals the specified value.

Supports both strictly typed object structures and looser records with optional properties.

Useful for filtering arrays of objects based on property values.
Type Parameters
- V
  The value type of the property (loose overload).
- K extends PropertyKey
  The key of the property to compare.
Parameters
- key: K
  The property name to compare.
- value: V
  The value to match against.
Returns (obj: Partial<Record<K, V>>) => boolean
A predicate for use with arrays of type T.
Example
```
// Strict object structure
const isAdmin = RecordCore.onKeyEqual<User, 'role'>('role', 'admin');
const admins = users.filter(isAdmin);
```
Example
```
// Loosely typed object
const isPublished = RecordCore.onKeyEqual('status', 'published');
const publishedPosts = posts.filter(isPublished);
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:201

`Static`onKeyNotEqual

onKeyNotEqual<
    T extends Record<PropertyKey, any>,
    K extends string | number | symbol,
>(
    key: K,
    value: T[K],
): (obj: T) => boolean
Creates a predicate function that checks whether a given object's property does not equal the specified value.

Supports both strictly typed object structures and looser records with optional properties.

Useful for filtering arrays of objects where you want to exclude items with a certain property value.
Type Parameters
- T extends Record<PropertyKey, any>
  The object type with known keys (strict overload).
- K extends string | number | symbol
  The key of the property to compare.
Parameters
- key: K
  The property name to compare.
- value: T[K]
  The value to check against.
Returns (obj: T) => boolean
A predicate function returning true when obj[key] !== value.
Example
```
// Strict object structure
const isNotAdmin = RecordCore.onKeyNotEqual<User, 'role'>('role', 'admin');
const nonAdmins = users.filter(isNotAdmin);
```
Example
```
// Loosely typed object
const isNotPublished = RecordCore.onKeyNotEqual('status', 'published');
const draftsOrArchived = posts.filter(isNotPublished);
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:233
onKeyNotEqual<V, K extends PropertyKey>(
key: K,
value: V,
): (obj: Partial<Record<K, V>>) => boolean
Creates a predicate function that checks whether a given object's property does not equal the specified value.

Supports both strictly typed object structures and looser records with optional properties.

Useful for filtering arrays of objects where you want to exclude items with a certain property value.
Type Parameters
- V
  The value type of the property (loose overload).
- K extends PropertyKey
  The key of the property to compare.
Parameters
- key: K
  The property name to compare.
- value: V
  The value to check against.
Returns (obj: Partial<Record<K, V>>) => boolean
A predicate function returning true when obj[key] !== value.
Example
```
// Strict object structure
const isNotAdmin = RecordCore.onKeyNotEqual<User, 'role'>('role', 'admin');
const nonAdmins = users.filter(isNotAdmin);
```
Example
```
// Loosely typed object
const isNotPublished = RecordCore.onKeyNotEqual('status', 'published');
const draftsOrArchived = posts.filter(isNotPublished);
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:234

`Static`pick

pick<K extends PropertyKey, T extends Partial<Record<K, unknown>>>(
keys: Iterable<K>,
value: T,
): Pick<T, K>
Pick function to pick keys from an object or use as map function to pick keys from an array
Type Parameters
- K extends PropertyKey
  Pick keys
- T extends Partial<Record<K, unknown>>
  Object type
Parameters
- keys: Iterable<K>
  keys to pick
- value: T
  to pick from (optional)
Returns Pick<T, K>
picked object or map function
Example
```
type Data = {demo: string, value: number|null};
const data: Data = {demo: 'hello', value: null};
const output: Pick<Data, 'value'> = RecordCore.pick(['value'], data);
const dataArray: Data[] = [{demo: 'hello', value: null}];
const output: Pick<Data, 'demo'>[] = dataArray.map(RecordCore.pick(['demo']));
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:135
pick<K extends PropertyKey>(
keys: Iterable<K>,
): <T extends Partial<Record<K, unknown>>>(value: T) => Pick<T, K>
Pick function to pick keys from an object or use as map function to pick keys from an array
Type Parameters
- K extends PropertyKey
  Pick keys
Parameters
- keys: Iterable<K>
  keys to pick
Returns <T extends Partial<Record<K, unknown>>>(value: T) => Pick<T, K>
picked object or map function
Example
```
type Data = {demo: string, value: number|null};
const data: Data = {demo: 'hello', value: null};
const output: Pick<Data, 'value'> = RecordCore.pick(['value'], data);
const dataArray: Data[] = [{demo: 'hello', value: null}];
const output: Pick<Data, 'demo'>[] = dataArray.map(RecordCore.pick(['demo']));
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:136

`Static`values

values<R extends object>(value: R): ObjectMappedArray<R, R[keyof R]>
Type-safe Object.values() with overload for NonEmptyArray
Type Parameters
- R extends object
  The object shape
Parameters
- value: R
  The object shape to get the values from
Returns ObjectMappedArray<R, R[keyof R]>
Array of object values
Example
```
const result1: NonEmptyReadonlyArray<'value'> = RecordCore.values({key: 'value'} as const);
const result2: Array<string> = RecordCore.values({key: 'value'});
const result3: [] = RecordCore.values({});
```
Since
v1.0.0
- Defined in src/lib/RecordCore.mts:67

Class RecordCore

Since

Index

Methods

Methods

Staticassert

Parameters

Returns asserts value is Record<PropertyKey, unknown>

Throws

Since

StaticbuildErr

Parameters

Returns TypeError

Since

Staticentries

Type Parameters

Parameters

Returns ObjectMappedArrayTuples<R>

Example

Since

Staticis

Parameters

Returns value is Record<PropertyKey, unknown>

Since

StaticisNot

Type Parameters

Parameters

Returns value is Exclude<T, Record<PropertyKey, unknown>>

Since

Statickeys

Type Parameters

Parameters

Returns ObjectMappedArray<R, keyof R>

Example

Since

Staticomit

Type Parameters

Parameters

Returns Omit<T, K>

Example

Since

Type Parameters

Parameters

Returns <T extends Partial<Record<K, unknown>>>(value: T) => Omit<T, K>

Example

Since

StaticonKey

Type Parameters

Parameters

Returns (target: T) => T[K]

Example

Since

Type Parameters

Parameters

Returns <T extends Record<K, any>>(target: T) => T[K]

Example

Since

StaticonKeyEqual

Type Parameters

Parameters

Returns (obj: T) => boolean

Example

Example

Since

Type Parameters

Parameters

Returns (obj: Partial<Record<K, V>>) => boolean

Example

Example

Since

StaticonKeyNotEqual

Type Parameters

Parameters

Returns (obj: T) => boolean

Example

Example

Since

Type Parameters

Parameters

Returns (obj: Partial<Record<K, V>>) => boolean

`Static`assert

`Static`buildErr

`Static`entries

`Static`is

`Static`isNot

`Static`keys

`Static`omit

`Static`onKey

`Static`onKeyEqual

`Static`onKeyNotEqual

`Static`pick

`Static`values