Construct custom exception modules which automatically derive the Tux.Alertable protocol. The generated error type will have the following fields:

• :message - short error message which will be used as title
• :details - detailed explanation of the error (.e.g. info about possible resolutions, etc)
• :exitcode - exit code to be used at escript's termination

Use Options

When constructing new error modules with use Tux.Error, the following options are available:

• :message (required) – main error message to use for the struct
• :exitcode (optional) – exit code (default is 1)

Examples

defmodule MyError do
  use Tux.Error, message: "MyError Occurred"
end

defmodule MyOtherError do
  use Tux.Error, message: "MyError Occurred", exitcode: 100
end

Now you can raise or return the error from your command modules:

raise MyError
{:error, %MyError{...}}

A useful idea is to define a new/1 function in your error module which accepts specific information and constructs a more detailed error:

defmodule FieldError do
  use Tux.Error, message: "Field is Missing"

  def new(fieldname: fieldname) do
    struct!(__MODULE__, details: """
    The #{red(fieldname)} is missing.
    """)
  end
end

Here's how the Tux.Alertable protocol behaves when invoked with a tux error struct:

defmodule MyError do
  use Tux.Error, message: "Some Error Occurred"
end

error = %MyError{}
assert Tux.Alertable.title(error) == "Some Error Occurred"
assert Tux.Alertable.message(error) == nil

error = MyError{details: "This error is really, really bad."}
assert Tux.Alertable.title(error) == "Some Error Occurred"
assert Tux.Alertable.message(error) == "This error is really, really bad."