TypeScript

The "NotFoundError" in TypeScript often arises when the compiler can't find a specified module, file, or declaration. To fix this, first ensure all necessary packages are installed by running `npm install` or `yarn install`. Then, double-check import paths and file names for typos or incorrect relative/absolute paths in your TypeScript code and tsconfig.json.

BadRequestError in TypeScript often arises when the compiler inadequately infers generic types within asynchronous functions, especially those involving discriminated unions like Result/Ok/Err. To fix this, explicitly provide type arguments to the function call or add type annotations to guide the compiler's inference process, ensuring the return type is properly resolved, especially when dealing with branching logic. Also, verify that your type definitions don't have circular references or overly complex constraints that confuse the type checker.

InvalidInputError usually indicates that the provided input fails to meet the expected type or format, especially within conditional branches or exhaustiveness checks. Resolve this by carefully validating input types, ensuring all possible input values are handled in conditional statements (e.g., using `else` or a `default` case in switch statements), or employing type guards to narrow down input types before use. Alternatively, if using discriminated unions, verify that exhaustiveness checks cover all union members by using `never` or a similar mechanism.

The "NotAnError" TypeScript error usually arises when a type representing an error is used where a generic type or conditional type expects a concrete error class or interface. Ensure that your error types are properly defined (e.g., using `class` or `interface`) and that you are correctly referencing or extending built-in `Error` types to satisfy the compiler's type constraints; explicitly cast or use type guards if necessary to narrow the type to a known error type.