{"id":12328,"library":"util-ts-types","title":"Essential TypeScript Utility Types","description":"util-ts-types is a TypeScript utility library providing a curated collection of essential, reusable type constructs designed to simplify complex type manipulations within TypeScript projects. Currently at version 1.0.0, this package appears to be primarily maintained for internal consumption, evidenced by its 'private' designation in the README. As a type-only library, its release cadence is likely tied to internal project needs rather than public API changes, implying stability but infrequent external updates for the broader community. Key differentiators typically involve a set of opinionated or project-specific utility types that might not be available directly in TypeScript's built-in `lib.d.ts` or widely adopted libraries like `type-fest`, focusing on solving specific organizational typing challenges without introducing runtime dependencies.","status":"active","version":"1.0.0","language":"javascript","source_language":"en","source_url":null,"tags":["javascript","typescript"],"install":[{"cmd":"npm install util-ts-types","lang":"bash","label":"npm"},{"cmd":"yarn add util-ts-types","lang":"bash","label":"yarn"},{"cmd":"pnpm add util-ts-types","lang":"bash","label":"pnpm"}],"dependencies":[],"imports":[{"note":"Always use 'import type' for type-only exports to ensure no runtime code is bundled or executed, improving tree-shaking and preventing module resolution errors in some environments.","wrong":"import { DeepPartial } from 'util-ts-types';","symbol":"DeepPartial","correct":"import type { DeepPartial } from 'util-ts-types';"},{"note":"This package exports only TypeScript types; attempting to 'require' it in CommonJS will result in a runtime error as there is no corresponding JavaScript module.","wrong":"const { Mutable } = require('util-ts-types');","symbol":"Mutable","correct":"import type { Mutable } from 'util-ts-types';"},{"note":"While 'import * as' syntax might be technically valid for type imports, it's generally best practice to use named type imports for clarity and better tooling support when specific types are known.","wrong":"import * as UtilTypes from 'util-ts-types';","symbol":"Maybe","correct":"import type { Maybe } from 'util-ts-types';"}],"quickstart":{"code":"import type { DeepPartial, Mutable, Maybe } from 'util-ts-types';\n\n// Imagine util-ts-types provides these utilities:\n\ninterface UserProfile {\n  readonly id: string;\n  name: string;\n  email: string;\n  settings?: { theme: string; notifications: boolean };\n}\n\n// DeepPartial: Makes all properties and sub-properties optional and mutable.\ntype PartialUserProfile = DeepPartial<UserProfile>;\n\nconst updates: PartialUserProfile = {\n  name: 'Jane Doe',\n  settings: { theme: 'dark' } // 'notifications' is optional\n};\n\n// Mutable: Removes 'readonly' modifiers from properties.\ntype WritableUserProfile = Mutable<UserProfile>;\n\nlet user: WritableUserProfile = {\n  id: 'abc-123', // 'id' is now writable\n  name: 'John Doe',\n  email: 'john@example.com'\n};\nuser.id = 'new-id-456'; // This would error without Mutable\n\n// Maybe: Wraps a type to include 'null' or 'undefined'.\ntype OptionalEmail = Maybe<string>;\n\nconst primaryEmail: OptionalEmail = 'user@example.com';\nconst secondaryEmail: OptionalEmail = null;\nconst tertiaryEmail: OptionalEmail = undefined;\n\nconsole.log(`User email: ${primaryEmail ?? 'Not provided'}`);\n\n// Function demonstrating usage\nfunction updateProfile(current: UserProfile, patch: PartialUserProfile): UserProfile {\n  return { ...current, ...patch, settings: { ...current.settings, ...patch.settings } };\n}\n\nconst initialProfile: UserProfile = { id: '1', name: 'Original', email: 'orig@example.com' };\nconst updated = updateProfile(initialProfile, { name: 'New Name' });\nconsole.log(`Updated profile name: ${updated.name}`);\n","lang":"typescript","description":"This quickstart demonstrates the application of hypothetical `DeepPartial`, `Mutable`, and `Maybe` utility types to transform existing TypeScript interfaces and types, showcasing their primary use cases in data manipulation and type refinement."},"warnings":[{"fix":"Consider mirroring or vendoring essential types for critical internal projects if long-term stability or public dependency is a concern. Avoid using in external-facing libraries without careful consideration.","message":"This package is explicitly marked as '(Private)' in its README. While functional, it might not adhere to standard public API stability guarantees. Consumers should be aware that breaking changes might occur without semantic versioning considerations typical for public npm packages.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Always use `import type { ... } from 'util-ts-types';` for all imports to explicitly declare them as type-only, which helps bundlers and TypeScript compiler optimize correctly.","message":"As a type-only library, `util-ts-types` contains no runtime JavaScript code. Attempting to import it using `require()` in CommonJS environments or directly referencing it as a runtime dependency will lead to module resolution errors or unexpected behavior at runtime.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Consult the package's `index.d.ts` file or source code directly to verify available exports. If specific types are missing, consider contributing to the private repository or implementing them locally.","message":"The specific utility types provided by this package are not detailed in the truncated README. There's a risk that inferred or commonly expected utility types (e.g., `DeepPartial`, `Mutable`) may not actually be exported, leading to 'has no exported member' errors.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Ensure your project's `typescript` dependency meets or exceeds the version used to develop `util-ts-types`. If issues arise, try updating your TypeScript compiler.","message":"Reliance on specific TypeScript versions: Utility type libraries often leverage advanced TypeScript features. While `1.0.0` suggests stability, older TypeScript versions might not fully support all internal type definitions or lead to unexpected type inference issues.","severity":"gotcha","affected_versions":">=1.0.0"}],"env_vars":null,"last_verified":"2026-04-19T00:00:00.000Z","next_check":"2026-07-18T00:00:00.000Z","problems":[{"fix":"Ensure 'util-ts-types' is listed in your `package.json` and installed. Verify `tsconfig.json` paths. For type-only imports, ensure `import type` syntax is used.","cause":"The package is not installed, or your TypeScript configuration (e.g., `compilerOptions.typeRoots`, `paths`) is incorrect, or you are trying to `require()` it in a runtime context.","error":"Cannot find module 'util-ts-types' or its corresponding type declarations."},{"fix":"Check the `index.d.ts` file within the `util-ts-types` package to confirm the exact names and exports available. Adjust your import statement accordingly.","cause":"You are trying to import a type that is not actually exported by the library, or the case of the type name is incorrect.","error":"'util-ts-types' has no exported member 'SomeType'. Did you mean to use a default import?"},{"fix":"Review the definition of the utility type and how it transforms `X` into `Y`. Adjust your input type or expected type to match the transformation, or rethink the use of that specific utility type.","cause":"A utility type from `util-ts-types` was applied, but the resulting type `Y` is not compatible with the expected type `X` in your assignment or function call.","error":"Type 'X' is not assignable to type 'Y'."}],"ecosystem":"npm"}