ts-type-safe

Utilities and types for a more type-safe TypeScript

Modules

types

Helper types to improve type-safety.

classNames

Helper function to simplify type-safe work with classNames.

validators

Validators to improve type-safety.

types

Helper types to improve type-safety.

• types
  • ~Prettify : Prettify
  • ~ValuesOf : ValuesOf
  • ~KeysOf : KeysOf

types~Prettify : Prettify

Helper type to show all properties of a complex base-type

Kind: inner typedef of types

types~ValuesOf : ValuesOf

Helper type generates values of a given type

NOTE: not for enum-types! Use type EnumVals = `${EnumType}`; to create values of an enum-type

Kind: inner typedef of types
Example

const Foo = { A: "a", B: "b"} as const;
type FooVals = ValuesOf<typeof Foo>;
// type FooVals = "a" | "b"

// equivalent to: type FooVals = (typeof Foo)[keyof typeof Foo];

types~KeysOf : KeysOf

Helper type generates keys of a given type

Kind: inner typedef of types
Example

const Foo = { A: "a", B: "b"};
type FooKeys = KeysOf<typeof Foo>;
// type FooKeys = "A" | "B"

// equivalent to: type FooKeys = keyof typeof Foo;

classNames

Helper function to simplify type-safe work with classNames.

classNames~classNames()

Helper-Function to join multiple classes and to avoid usage of nasty string-literals

Kind: inner method of classNames

validators

Validators to improve type-safety.

• validators
  • ~hasOwnProperty()
  • ~isEnumKey()
  • ~isEnumValueGenerator()
  • ~isEnumValue(enumType, value)

validators~hasOwnProperty()

Checks existence of @propKey on an object and retypes the @obj

Kind: inner method of validators

validators~isEnumKey()

Typeguard for enums-keys

Kind: inner method of validators
Example

enum MyEnum {
 Thing1 = 'thing one',
 Thing2 = 'thing two',
}

function testKeys(key: keyof typeof MyEnum) {
  console.log(key, MyEnum[key]);
}

const testStr = "Thing2";

if (isEnumKey(MyEnum, testStr)) {
  // compiler knows that testStr is of type `keyof typeof MyEnum`
  testKeys(testStr);
}

validators~isEnumValueGenerator()

https://stackoverflow.com/questions/58278652/generic-enum-type-guard

Kind: inner method of validators

validators~isEnumValue(enumType, value)

Typeguard for enum values

Kind: inner method of validators
Todo:: take care of number-Enums

Example

enum MyEnum {
 Thing1 = 'thing one',
 Thing2 = 'thing two',
}

function testVals(val: MyEnum) {
  console.log("testVals", val);
}

const testStr = "thing two";

if (isEnumValue(MyEnum, testStr)) {
  // compiler knows that testStr is of type `MyEnum`
  testVals(testStr);
}

© 2023 Hans Krebs