typyx

Bullet-proof TypeScript, even more.

Installation

npm

npm i -D typyx

pnpm

pnpm i -D typyx

Requires TypeScript v5.0+.

Documentation

Check out the full API reference for detailed usage examples and docs.

Types

Object shape, keys, and modifiers

• Assign<Obj, ObjArr> - Copies all enumerable own properties from one target object to a source array of objects.
• FilterBy<Obj, P> - Filters keys from the object type Obj based on a specified predicate P.
• Flip<Obj> - Flips the keys and values of an object type Obj.
• ImmutableKeys<Obj> - Retrieves the readonly keys from an object type Obj.
• Keys<T> - Retrieves the union of keys of a type T.
• KeysOfUnion<T> - Extracts the union of keys from a union of object types.
• KeysToValues<Obj> - Creates a reverse mapping from values to keys for a simple object type.
• MakeOptional<T, K> - Makes the specified keys K optional while preserving the original modifiers of all other keys.
• MakeRequired<T, K> - Makes the specified keys K required while preserving the original modifiers of all other keys.
• Methods<Obj> - Gets the literal names of keys that are methods in an object type Obj.
• MutableKeys<Obj> - Retrieves the mutable keys from an object type Obj.
• NonRequiredKeys<Obj> - Returns all non-required keys of an object type Obj.
• NotIncluded - Marker type used with deep pruning utilities to completely omit fields.
• OmitByType<Obj, T> - Omits properties from Obj whose types are assignable to T.
• OmitCommonKeys<Obj1, Obj2> - Omits any keys shared by Obj1 and Obj2.
• OmitExactlyByTypeDeep<Obj, T> - Deeply omits properties whose types exactly match T.
• PickByType<Obj, T> - Picks properties from Obj whose types are assignable to T.
• PickCommonKeys<Obj1, Obj2> - Gets the common keys between two object types.
• PickExactlyByType<Obj, T> - Picks properties from Obj whose types exactly match T.
• Properties<Obj> - Gets the literal names of keys that are non-method properties in an object type Obj.
• Prune<T, N = NotIncluded> - Recursively omits properties of type N from T.
• ReplaceKeys<Obj1, P, Obj2> - Replaces properties P in Obj1 with the corresponding properties from Obj2.
• RequiredKeys<Obj> - Gets the required keys of an object type Obj.
• Vals<Obj> - Gets the union of value types from an object type.

Deep object utilities

• DeepAwaited<T> - Recursively resolves all nested Promise types to their underlying values.
• DeepImmutable<Obj> - Recursively makes every property in Obj readonly.
• DeepMutable<Obj> - Recursively removes readonly from every property in Obj.
• DeepNotRequired<Obj> - Recursively makes all properties optional.
• DeepOmit<Obj, P> - Recursively omits specified nested properties from an object based on path P.
• DeepPick<Obj, P> - Deeply picks properties from a nested object based on path P.
• DeepRequired<Obj> - Recursively makes all properties required.
• DeepToPrimitive<Obj> - Recursively transforms an object type into one whose properties are their primitive counterparts.
• IsDeepImmutable<Obj> - Checks if all nested properties of Obj are immutable.
• IsDeepMutable<Obj> - Checks if all nested properties of Obj are mutable.
• IsDeepNotRequired<Obj> - Checks if all nested properties of Obj are optional.
• IsDeepRequired<Obj> - Checks if all nested properties of Obj are required.
• Paths<Obj> - Generates all possible dot-separated key paths from a nested object type.

Union and composition utilities

• ExclusiveUnion<T> - Creates a union type where each variant keeps its own required properties while excluding incompatible ones.
• KeysOfUnion<T> - Extracts the full key union across a union of object types.
• NotAssignableTo<U, V> - Excludes all members of U that are assignable to V.
• TupleToUnion<T> - Converts a tuple type into a union type.
• UnionToIntersection<U> - Converts a union type into an intersection type.
• UnionToTuple<T> - Converts a union type into a tuple type.

Array and tuple utilities

• Append<Arr, Item> - Adds an item to the end of a tuple.
• EitherOneOrMany<T> - Represents either a single value of type T or an array of T.
• Head<Arr> - Gets the first element of a tuple.
• IsArrayIncludesTypeof<Arr, T> - Checks whether an array type Arr is assignable to T[].
• Last<Arr> - Gets the last element of a tuple.
• NonEmptyArray<T> - Represents an array containing at least one element of type T.
• Pop<Arr> - Removes the last element of a tuple.
• Prepend<Arr, Item> - Adds an item to the start of a tuple.
• SizedTuple<T, N> - Creates a tuple of length N where each element is of type T.
• Tail<Arr> - Removes the first element of a tuple.
• Tuple<T> - Narrows T to a tuple type and rejects regular arrays.
• UniqueArray<T> - Creates a unique array type from an array type T.
• Zip<L, L1> - Pairs elements from two tuples by index into a tuple of pairs.

String utilities

• CapitalizeFirst<T> - Capitalizes the first character of a string literal type.
• EnforcedString<Prefix, Contains, Suffix> - Restricts a string using optional prefix, substring, and suffix constraints.
• EqualStrlen<S1, S2> - Checks whether two strings have the same length.
• FilledString<S> - Errors on an empty string literal ''.
• NumerifyString<S> - Converts a string literal into a Numeric when possible.
• StringEndsWith<S, E> - Checks whether a string S ends with E.
• StringStartsWith<S, St> - Checks whether a string S starts with St.
• StringifyPrimitive<P> - Turns a primitive value type into its string representation.
• StrBetween<S, Min, Max> - Ensures a string S has a length within [Min, Max].
• Strlen<S> - Computes the length of a string S.
• StrMax<S, Max> - Ensures that a string S has length less than or equal to Max.
• StrMin<S, Min> - Ensures that a string S has length greater than or equal to Min.

Numeric utilities

• Abs<N> - Gets the absolute value of a Numeric.
• Even<T> - Represents an even Numeric.
• Float<N> - Type representing a float.
• Integer<N> - Represents an integer.
• IsFloat<N> - Checks if a given numeric type is a float.
• IsInteger<N> - Checks if a given numeric type is an integer.
• IsNegative<N> - Checks if a numeric type is negative.
• IsNegativeFloat<N> - Checks if a numeric type is a negative float.
• IsNegativeInteger<N> - Checks if a numeric type is a negative integer.
• IsPositive<N> - Checks if a numeric type is positive.
• IsPositiveFloat<N> - Checks if a numeric type is a positive float.
• IsPositiveInteger<N> - Checks if a numeric type is a positive integer.
• NegativeFloat<N> - Represents a negative Float<N>.
• NegativeFloatString<S> - Represents a negative float parsed from a string.
• NegativeInteger<N> - Represents a negative Integer<N>.
• NegativeIntegerString<S> - Represents a negative integer parsed from a string.
• Numeric - Represents number | bigint.
• Odd<T> - Represents an odd Numeric.
• PositiveFloat<N> - Represents a positive Float<N>.
• PositiveFloatString<S> - Represents a positive float parsed from a string.
• PositiveInteger<N> - Represents a positive Integer<N>.
• PositiveIntegerString<S> - Represents a positive integer parsed from a string.
• PositiveRange<N, M> - Represents a range of positive integers from N to M inclusive.

Logic, comparison, and control flow

• And<B1, B2> - Logical AND between two boolean types.
• Equals<X, Y> - Checks if two types are exactly equal.
• If<C, Do, Else> - Resolves to Do if C is true, otherwise Else.
• IfEquals<T, P, Do, Else> - Resolves to Do if T equals P, otherwise Else.
• IfExtends<T, P, Do, Else> - Resolves to Do if T extends P, otherwise Else.
• Nand<B1, B2> - Logical NAND between two boolean types.
• Nor<A, B> - Logical NOR between two boolean types.
• Not<B> - Negates a boolean type.
• Or<B1, B2> - Logical OR between two boolean types.
• Xand<A, B> - Logical XAND between two boolean types.
• Xnor<A, B> - Logical XNOR between two boolean types.
• Xor<B1, B2> - Logical XOR between two boolean types.

Type predicates and checkers

• Extends<T, U> - Evaluates whether type T is assignable to type U.
• FalsyProperties<T> - Extracts falsy properties from an object type T.
• Is<T, U> - Checks if two types are exactly identical.
• IsAnyFunction<T> - Checks if T is an arbitrary function type.
• IsArray<T> - Checks if T is an array type.
• IsBigInt<T> - Checks if T is a bigint.
• IsBoolean<T> - Checks if T is a boolean.
• IsExactlyAny<T> - Checks if T is exactly any.
• IsExactlyBigInt<T> - Checks if T is exactly bigint.
• IsExactlyNumber<T> - Checks if T is exactly number.
• IsExactlyString<T> - Checks if T is exactly string.
• IsExactlySymbol<T> - Checks if T is exactly symbol.
• IsExactlyUnknown<T> - Checks if T is exactly unknown.
• IsFalsy<T> - Checks if a given type T is Falsy.
• IsFunction<T> - Checks if a given type T is a function.
• IsNever<T> - Checks if a type resolves to never.
• IsNewable<T> - Checks if a type T is Newable.
• IsNot<T, U> - Checks if two types are not identical.
• IsNullable<T> - Checks if a type T is Nullable.
• IsNumber<T> - Checks if a type T is a number.
• IsNumeric<T> - Checks if a type T is Numeric.
• IsObject<T> - Checks if a type T qualifies as an object.
• IsString<T> - Checks if a type T is a string.
• IsSymbol<T> - Checks if a type T is a symbol.
• IsTruthy<T> - Checks if a type T resolves to a truthy value.
• IsUnknown<T> - Checks if a type T is assignable to unknown.
• TestType<T1, T2, Expected> - Tests whether T1 and T2 match the expected relationship.
• TruthyProperties<T> - Extracts truthy properties from an object type T.

Core, primitives, callables, and nullability

• AnyFunction - Represents any function accepting any arguments and returning any value.
• EmptyObject - Represents a non-nullish object-like value.
• ExcludeNull<T> - Excludes null from a type T.
• ExcludeNullable<T> - Excludes Nullable from a type T.
• ExcludeUndefined<T> - Excludes undefined from a type T.
• Falsy - Represents JavaScript falsy values.
• Maybe<T> - Represents a type that may be Nullable.
• MaybeUndefined<T> - Represents a type that may be undefined.
• MaybeUnknown<T> - Represents a type widened with unknown.
• Message<T> - Used to surface readable error messages instead of never.
• Newable - Represents constructor functions that can be invoked with new.
• NewType<New, Base> - Creates a branded type derived from an existing base type.
• Nullable - Represents a type that can be null or undefined.
• Optional<T> - Represents a type that may be null, similar to Python's Optional or Rust's Option.
• PartialExcept<T, P> - Makes all properties in T optional except those in P, which remain required.
• Primitive - Represents all JavaScript primitive types.
• Simplify<T> - Flattens and normalizes a type for better readability.
• UnknownFunction - Represents a function accepting unknown arguments and returning unknown.

The best way to understand how these types work is to check the tests directory.

Changelog

See releases.

License

MIT © @rccyx