security-considerations-in-typescript

• TypeScript Does Not Guarantee Runtime Security:

  Remember that TypeScript's type system is a compile-time construct and does not enforce security at runtime. Runtime checks are still necessary.

• Input Validation:

  Even with strong types, always validate user input at runtime to protect against malicious data, as types are stripped away after compilation.

• Avoiding any Type for Sensitive Data:

  Use specific types instead of the any type for handling sensitive information to benefit from TypeScript's type-checking.

• Protecting Against Injection Attacks:

  Ensure that any dynamic generation of code or queries (like SQL or command line calls) is done using parameterized statements or APIs that prevent injection.

• Using Type Guards:

  Implement type guards to validate data structures at runtime, especially when receiving data from untyped or external sources.

• Securing Third-Party Types:

  Be cautious when importing types from third-party libraries; ensure they are from a reputable source and do not introduce vulnerabilities.

• Keeping Dependencies Up to Date:

  Regularly update your TypeScript and other dependencies to ensure you have the latest security patches.

• Using TypeScript for Security Rules:

  When possible, encode security rules and business logic as types to leverage compile-time checking for security policies.

• Securing the Build Environment:

  Ensure that the TypeScript compilation environment is secure to prevent the injection of malicious code during the build process.

• Avoid Exposing Sensitive Types:

  Do not expose sensitive information through type definitions in public-facing APIs, as this can reveal details about the backend systems.

• Immutable Data Patterns:

  Use TypeScript's readonly modifier and immutable data patterns to prevent accidental or malicious modification of objects after creation.

• Securing TypeScript Configuration:

  Safeguard tsconfig.json settings to prevent misconfigurations that could expose source maps or other sensitive information in production.

• Security in Type Declarations:

  Pay attention to the security of declaration files (*.d.ts) as they can affect the integrity of the type system if compromised.

• Runtime Type Checks:

  Consider runtime type checking libraries for critical sections where data integrity is paramount, to ensure data conforms to TypeScript types at runtime.

• Code Reviews for Type Safety:

  Conduct thorough code reviews with a focus on type safety and security, as TypeScript can enforce certain security principles through its type system.