More meaningful error messages

[stefanbc]

Just as the names suggest, right now the error messages when some part of the script crashes are very confusing and don't explain the exact error.

Each step should output a meaningful error message.

[s4kh]

Can you give me an example case? Like after executing the script with given 'arguments' the shown error message does not make sense.

[stefanbc]

@s4kh when the update command crashes because one of the steps didn't execute it outputs this

or begin
    set -l err $status
    echo "Ghost update encountered an error. Exit status: $err."
    exit $err
end

So we know the status of the error but the user doesn't actually know why the script crashed. The user can see that it stopped at some step but that doesn't mean it's the actual cause of the crash.

I would do something like this after each step:

(pseudo code)

echo "Step 1: getting the latest Ghost version"
and curl -LOk https://ghost.org/zip/ghost-latest.zip
and mv ghost-latest.zip /tmp/ghost-latest.zip

or begin
   <call to function that outputs an error and exists>

In this case it would be something like

$: Step 1: getting the latest Ghost version
$: Ghost update encountered an error. The script failed to download the latest version of Ghost

Hope it makes sense.

[s4kh]

OK got it. Makes sense

[s4kh]

Currently, I am doing something like this.

function error_exit
{
    echo "${1:-"Unknown Error"}" 1>&2
    exit 1
}

And after every step:

or begin
   error_exit "$LINENO: Failed to download the latest version of Ghost"