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Validation Decorators Reference

Common Validation Decorators

Decorator Description
@IsDefined(value: any) Checks if value is defined (!== undefined, !== null).
@IsOptional() Ignores all validators if value is empty.
@Equals(comparison: any) Checks if value equals comparison.
@NotEquals(comparison: any) Checks if value not equals comparison.
@IsEmpty() Checks if given value is empty.
@IsNotEmpty() Checks if given value is not empty.
@IsIn(values: any[]) Checks if value is in a array of allowed values.
@IsNotIn(values: any[]) Checks if value is not in a array of disallowed values.

String Validation Decorators

Decorator Description
@IsString() Checks if the string is a string.
@Length(min: number, max?: number) Checks if the string's length falls in range.
@MinLength(min: number) Checks if the string's length is not less than given number.
@MaxLength(max: number) Checks if the string's length is not more than given number.
@Matches(pattern: RegExp) Checks if string matches the pattern.
@IsEmail() Checks if the string is an email.
@IsURL() Checks if the string is an URL.
@IsFQDN() Checks if the string is a fully qualified domain name.

Number Validation Decorators

Decorator Description
@IsNumber() Checks if the value is a number.
@IsInt() Checks if the value is an integer.
@Min(min: number) Checks if the value is greater than or equal to given number.
@Max(max: number) Checks if the value is less than or equal to given number.
@IsPositive() Checks if the value is a positive number.
@IsNegative() Checks if the value is a negative number.

Date Validation Decorators

Decorator Description
@IsDate() Checks if the value is a Date.
@MinDate(date: Date) Checks if the date is greater than given date.
@MaxDate(date: Date) Checks if the date is less than given date.

Array Validation Decorators

Decorator Description
@IsArray() Checks if the value is an array
@ArrayContains(values: any[]) Checks if array contains all values from the given array
@ArrayNotContains(values: any[]) Checks if array does not contain any of the given values
@ArrayNotEmpty() Checks if given array is not empty
@ArrayMinSize(min: number) Checks if array's length is greater than or equal to specified number
@ArrayMaxSize(max: number) Checks if array's length is less or equal to specified number
@ArrayUnique() Checks if all array's values are unique