@buka/class-transformer-extra
@buka/class-transformer-extra contains methods that's aren't included in the class-transformer package.
Install
npm install @buka/class-transformer-extra class-transformer
# OR
yarn install @buka/class-transformer-extra class-transformer
# OR
pnpm install @buka/class-transformer-extra class-transformer
Usage
String
| method | before transformer | after transformer |
|---|---|---|
@Split(",") | "a,b,c" | ["a", "b", "c"] |
@Trim() | " abc " | "abc" |
@ToString({ optional: true }) | 123 | "123" |
@ToLowerCase() | "ABC" | "abc" |
@ToUpperCase() | "abc" | "ABC" |
@Replace("-", "_") | "a-b-c" | "a_b_c" |
@Split,@Trim,@ToLowerCase,@ToUpperCaseand@Replacewill do nothing if the value isn't string. When setoptional: true,undefinedwill not be transformed.
Date
| method | before transformer | after transformer |
|---|---|---|
@ToDate({ optional: true }) | "2024-01-01" | new Date("2024-01-01") |
@FormatDate("YYYY/MM/DD", { optional: true }) | "2024-01-01" | "2024/01/01" |
Number
| method | before transformer | after transformer |
|---|---|---|
@ToNumber({ optional: true }) | "123" | 123 |
@ToBigInt({ optional: true }) | "123" | 123n |
ToNumber()and@ToBigInt()will return NaN if the value isn't number
Boolean
| method | before transformer | after transformer |
|---|---|---|
@ToBoolean() | 1 | true |
ToBoolean()has multiple parameters to adapt to different needs, examples:
ToBoolean(v => Boolean(v)), { optional: true }): If the value isundefined, do nothing. Otherwise,v => Boolean(v)will be used to transform value.
ToBoolean(['0', 'false', false], { optional: true }):If the value is
'0'or'false'orfalse, transform tofalse, and if the value isundefined, do nothing, otherwise value will be transform totrue.
Array
| method | before transformer | after transformer |
|---|---|---|
@Filter((num: number) => num > 3) | [1,2,3.4,5] | [4,5] |
@Flatten() | [1, [2, [3, 4, [5]]]] | [1,2,3,4,5] |
@Uniq() | [1,1,2,3,4,4,5] | [1,2,3,4,5] |
@UniqBy(Math.abs) | [-1, 1, 2, 3, -3] | [-1, 2, 3] |
@Filter,@Flatten,@Uniqand@UniqBywill do nothing if the value isn't array.
Contribute
If you want to report bug or add new decorators, please submit an Issue or Pull Request.
Q&A
-
Why can't it be used with the
@IsOptionaldecorator?The latest version of
class-validator@^0.14.1is not set metadata that can identify@IsOptional. If the identifiers are added in later versions, I will also follow up. And the identifier had be add in develop branch ofclass-validator.