TypeScript with some extras for type-checking.
JavaScript
29
131 commits
updated Jul 9, 2026
TypeScript with some extras for type-checking.
This is a drop-in replacement for TypeScript meant for programmatic usage only. It does not expose the binaries like tsc and tsserver because it would override the TypeScript binaries of the project. It exposes extra methods on the internal TypeChecker object.
npm install --save-dev @tsd/typescript
This package is just TypeScript with some private methods exposed that tsd needs for enhanced type checking.
isTypeIdenticalTo(a: Type, b: Type): Check if two types are identical to each other. More info...isTypeSubtypeOf(a: Type, b: Type): Check if type a is a subtype of type b. More info...isTypeAssignableTo(a: Type, b: Type): Check if type a is assignable to type b.isTypeDerivedFrom(a: Type, b: Type): Check if type a is derived from type b. More info...isTypeComparableTo(a: Type, b: Type): Check if type a is comparable to type b. More info...areTypesComparable(a: Type, b: Type): Check if type a is comparable to type b and b is comparable to type a. More info...84,743 followers · starred Dec 2020
622 followers · starred Aug 2025
TypeScript with some extras for type-checking.
JavaScript
29
131 commits
updated Jul 9, 2026
TypeScript with some extras for type-checking.
This is a drop-in replacement for TypeScript meant for programmatic usage only. It does not expose the binaries like tsc and tsserver because it would override the TypeScript binaries of the project. It exposes extra methods on the internal TypeChecker object.
npm install --save-dev @tsd/typescript
This package is just TypeScript with some private methods exposed that tsd needs for enhanced type checking.
isTypeIdenticalTo(a: Type, b: Type): Check if two types are identical to each other. More info...isTypeSubtypeOf(a: Type, b: Type): Check if type a is a subtype of type b. More info...isTypeAssignableTo(a: Type, b: Type): Check if type a is assignable to type b.isTypeDerivedFrom(a: Type, b: Type): Check if type a is derived from type b. More info...isTypeComparableTo(a: Type, b: Type): Check if type a is comparable to type b. More info...areTypesComparable(a: Type, b: Type): Check if type a is comparable to type b and b is comparable to type a. More info...84,743 followers · starred Dec 2020
622 followers · starred Aug 2025