Error

Functions for working with JavaScript exceptions.

See Error on MDN.

fileName(error) retrieves the fileName property of the error, if it exists.

See Error.prototype.fileName on MDN.

ignore(error) ignores the provided error and returns unit.

This helper is useful when you want to discard a value (for example, the result of an operation with side effects) without having to store or process it further.

make(message) creates a new error, setting its message to the provided value.

See Error on MDN.

Example

RESCRIPT
let error = Error.make("Some message here")
Console.log(error->Error.message) // Logs "Some message here" to the console
Console.log(error->Error.name) // Logs "Error" to the console, because this is a regular error

message(error) retrieves the message property of the error, if it exists.

See Error.prototype.message on MDN.

Example

RESCRIPT
let error = Error.SyntaxError.make("Some message here")
Console.log(error->Error.message) // Logs "Some message here" to the console

name(error) retrieves the name property of the error, if it exists.

See Error.prototype.name on MDN.

Example

RESCRIPT
let error = Error.SyntaxError.make("Some message here")
Console.log(error->Error.name) // Logs "SyntaxError" to the console

Throws a panic exception with the given message.

A panic exception is a native JavaScript exception that is not intended to be caught and handled. Compared to a ReScript exception this will give a better stack trace and debugging experience.

Examples

RESCRIPT
try {
  Error.panic("Uh oh. This was unexpected!")
} catch {
| Exn.Error(obj) =>
  switch Exn.message(obj) {
  | Some(m) => assert(m == "Panic! Uh oh. This was unexpected!")
  | None => assert(false)
  }
| _ => assert(false)
}

Raises (throws in JavaScript language) the provided Error.t, which will stop execution.

Examples

RESCRIPT
let error = Error.make("Everything is upside down.")

if 5 > 10 {
  error->Error.raise
} else {
  Console.log("Phew, sanity still rules.")
}

stack(error) retrieves the stack property of the error, if it exists. The stack is a list of what functions were called, and what files they are defined in, prior to the error happening.

See Error.prototype.stack on MDN.

Example

RESCRIPT
let error = Error.make("error")
Console.log(error->Error.stack) // Logs `stack` if it exists on `someError`

Represents a JavaScript exception.

Throws the given exception, terminating execution unless caught by a surrounding try/catch block.

Examples

RESCRIPT
let error = Error.make("Everything is upside down.")

if 5 > 10 {
  Error.throw(error)
} else {
  Console.log("Phew, sanity still rules.")
}

Turns an Error.t into an exn.

Examples

RESCRIPT
let error = Error.make("Something went wrong.")

let asExn = error->Error.toException // `asExn` is now type `exn`