mattpocock/ts-reset
Ts Reset
ts-reset is a TypeScript type enhancement library that overrides and augments the built-in type definitions for standard JavaScript APIs. Its core purpose is to replace unsafe any return types with stricter alternatives like unknown, forcing developers to explicitly validate data before using it. The library achieves this through global type augmentation and declaration merging, applying changes across the entire project without requiring per-file imports.
The library differentiates itself by targeting specific pain points in everyday TypeScript usage. It relaxes type constraints on array methods like includes and indexOf for readonly arrays, allowing membership checks and index lookups with values that don't match the array's element type. Similarly, it widens Map.has and Set.has to accept broader value types during existence checks. For array filtering, it injects Boolean as a type predicate, narrowing filtered results to exclude falsy values. On the safety side, it hardens browser storage API return types and changes JSON.parse and Response.json to return unknown instead of any, preventing unsafe access patterns.
The broader capability surface includes conditional type narrowing for standard APIs, type predicate injection into filter callbacks, and stricter type guarding for Array.isArray checks. These changes collectively enforce a more rigorous type safety posture for common JavaScript operations without requiring manual type annotations or wrapper functions. The library is distributed as a single package that can be added to any TypeScript project, applying its type improvements globally through declaration merging.
Features
- Type Safety Resets - Improves default TypeScript types for common JavaScript APIs to catch more errors and require explicit validation.
- Type-Safe Local Storage - Hardens browser storage API return types to prevent unsafe data access patterns.
- Global Type Augmentations - Overrides built-in TypeScript type definitions globally using declaration merging to change default behavior.
- Conditional Types - Uses conditional types to widen or tighten type constraints on standard JavaScript APIs like Array and Map.
- Unknown-First Return Types - Replaces any return types with unknown in methods like JSON.parse and Response.json to enforce type safety.
- Widened Set Membership Checks - Widens Set.has type constraints to accept broader value types during membership checks.
- Map Key Validation - Relaxes Map.has type constraints to accept broader value types during key existence checks.
- Widened Key Existence Checks - Widens Map.has type constraints to accept broader value types during key existence checks.
- Rigorous Type Set Operations - Widens Set.has type constraints to accept broader value types during membership checks.
- Type Enhancement Libraries - A library that improves built-in TypeScript types for common JavaScript APIs, replacing unsafe any types with stricter alternatives.
- Boolean Type Predicate Filters - Removes falsy values from an array type by using Boolean as a type predicate in the filter method.
- Widened Includes on Const Arrays - Checks membership in readonly arrays without requiring the search value to match the array's element type.
- Truthy Array Filters - Removes falsy values from an array by passing Boolean as the filter callback and narrowing the result type.
- Strict Response.json Return Types - Narrows Response.json return type to unknown instead of any so you must validate the data before use.
- Safe JSON Parsing - Converts JSON strings into unknown instead of any so you must check the type before accessing properties.
- Readonly Array Method Wideners - Relaxes type checking on readonly array methods like includes and indexOf to accept broader value types.
- Strict JSON.parse Return Types - Narrows JSON.parse return type to unknown instead of any so you must verify the result before using it.
- Array.isArray - Checks whether a value is an array and narrows its type to unknown instead of any for precise type guarding.
- Loosened Array Index Finders - Locates a value's position in a readonly array without requiring the value to match the array's element type.
- Widened IndexOf on Const Arrays - Finds positions in readonly arrays without requiring the search value to match the array's element type.
- Loosened Array Membership Checks - Checks if a value exists in a readonly array without requiring the value to match the array's element type.
- Type Predicate Injections - Injects Boolean as a type predicate into filter callbacks to narrow array results to truthy values.
- Array Type Guards - Verifies whether a value is an array and narrows its type to unknown instead of any for safer handling.
- Safe Fetch Response Parsing - Converts fetch response bodies to unknown instead of any to encourage explicit result validation.
- Storage API Type Hardening - Strictens the return types of browser storage APIs to prevent unsafe access patterns.
