👀 Sniffly

A lightweight TypeScript utility library for performing common type-safe value checks with type narrowing.

Install

``
npm i sniffly
`

Functions

$3

Checks that an iterable is not empty

#### ⚙️ Arguments:

value - object having a length attribute

$3

Checks that a dictionary is not empty

#### ⚙️ Arguments:

value - key/value pair dictionnary

$3

Checks that the value is a boolean

#### ⚙️ Arguments:

value - unknown value to check

$3

Checks that the value is a number satisfying optionnal specifications\
Remark:\
NaN is not considered as a valid number

#### ⚙️ Arguments:

value - unknown value to check\
options (dict) - optionnal additionnal specifications\
options.positive (boolean) - checks number is > 0\
options.min (number) - checks number is >= min\
options.max (number) - checks number is <= max

$3

Checks that the value is a string satisfying optionnal specifications

#### ⚙️ Arguments:

value - unknown value to check\
options (dict) - optionnal additionnal specifications\
options.nonEmpty (boolean) - checks that string is not empty\
options.regexPattern (RegExp) - checks that string matches pattern

$3

Checks that the value is an array satisfying optionnal specifications

#### ⚙️ Arguments:

value - unknown value to check\
options (dict) - optionnal additionnal specifications\
options.nonEmpty (boolean) - checks that the array has items\
options.itemType (string literal) - check type of array's items, following values are accepted:
- "unknown" (default) - items aren't checked
- "any" - items aren't checked
- "string" - string items only
- "number" - number items only
- "boolean" - boolean itemps only
- "array" - Array items only
- "dict" - Record items only

$3

Checks that the value is a key/value pair dictionnary satisfying optionnal specifications\
Remark:\
Only allows objects directly created from {} or Object.create(Object.prototype).\
Are considered invalid:
- Objects built from classes like const obj = new Foo() or built-ins like Array, Map, Set or Date
- Objects with no prototype like const obj = Object.create(null)

#### ⚙️ Arguments:

value - unknown value to check\
options (dict) - optionnal additionnal specifications\
options.nonEmpty (boolean) - checks that the dictionnary has entries\
options.keys (string array) expected keys that should be present in the dict\
options.itemType (string literal) - check type of entries, following values are accepted:
- "unknown" (default) - entries aren't checked
- "any" - entries aren't checked
- "string" - string entries only
- "number" - number entries only
- "boolean" - boolean entries only
- "array" - Array entries only
- "dict" - Record entries only

Types

$3

Type of key/value pair dictionnary, with a string key.
EntriesType generic represents the type of the entries of the dictionnary.

#### Example

`typescript
const data: Dict_T = { 'a': 1, 'b': 2 }
``