74 lines
2.0 KiB
TypeScript
74 lines
2.0 KiB
TypeScript
import type {WordSeparators} from '../source/internal';
|
|
import type {Split} from './split';
|
|
|
|
/**
|
|
Step by step takes the first item in an array literal, formats it and adds it to a string literal, and then recursively appends the remainder.
|
|
|
|
Only to be used by `CamelCaseStringArray<>`.
|
|
|
|
@see CamelCaseStringArray
|
|
*/
|
|
type InnerCamelCaseStringArray<Parts extends readonly any[], PreviousPart> =
|
|
Parts extends [`${infer FirstPart}`, ...infer RemainingParts]
|
|
? FirstPart extends undefined
|
|
? ''
|
|
: FirstPart extends ''
|
|
? InnerCamelCaseStringArray<RemainingParts, PreviousPart>
|
|
: `${PreviousPart extends '' ? FirstPart : Capitalize<FirstPart>}${InnerCamelCaseStringArray<RemainingParts, FirstPart>}`
|
|
: '';
|
|
|
|
/**
|
|
Starts fusing the output of `Split<>`, an array literal of strings, into a camel-cased string literal.
|
|
|
|
It's separate from `InnerCamelCaseStringArray<>` to keep a clean API outwards to the rest of the code.
|
|
|
|
@see Split
|
|
*/
|
|
type CamelCaseStringArray<Parts extends readonly string[]> =
|
|
Parts extends [`${infer FirstPart}`, ...infer RemainingParts]
|
|
? Uncapitalize<`${FirstPart}${InnerCamelCaseStringArray<RemainingParts, FirstPart>}`>
|
|
: never;
|
|
|
|
/**
|
|
Convert a string literal to camel-case.
|
|
|
|
This can be useful when, for example, converting some kebab-cased command-line flags or a snake-cased database result.
|
|
|
|
@example
|
|
```
|
|
import type {CamelCase} from 'type-fest';
|
|
|
|
// Simple
|
|
|
|
const someVariable: CamelCase<'foo-bar'> = 'fooBar';
|
|
|
|
// Advanced
|
|
|
|
type CamelCasedProperties<T> = {
|
|
[K in keyof T as CamelCase<K>]: T[K]
|
|
};
|
|
|
|
interface RawOptions {
|
|
'dry-run': boolean;
|
|
'full_family_name': string;
|
|
foo: number;
|
|
BAR: string;
|
|
QUZ_QUX: number;
|
|
'OTHER-FIELD': boolean;
|
|
}
|
|
|
|
const dbResult: CamelCasedProperties<RawOptions> = {
|
|
dryRun: true,
|
|
fullFamilyName: 'bar.js',
|
|
foo: 123,
|
|
bar: 'foo',
|
|
quzQux: 6,
|
|
otherField: false
|
|
};
|
|
```
|
|
|
|
@category Change case
|
|
@category Template literal
|
|
*/
|
|
export type CamelCase<K> = K extends string ? CamelCaseStringArray<Split<K extends Uppercase<K> ? Lowercase<K> : K, WordSeparators>> : K;
|