failure.sh

#!/usr/bin/env bash


# Bash Trap Failure, a submodule for other Bash scripts tracked by Git
# Copyright (C) 2019  S0AndS0
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation; version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.


## Outputs Front-Mater formatted failures for functions not returning 0
## Use the following line after sourcing this file to set failure trap
##    trap 'failure "LINENO" "BASH_LINENO" "${BASH_COMMAND}" "${?}"' ERR
failure(){
    local -n _lineno="${1:-LINENO}"
    local -n _bash_lineno="${2:-BASH_LINENO}"
    local _last_command="${3:-${BASH_COMMAND}}"
    local _code="${4:-0}"

    ## Workaround for read EOF combo tripping traps
    ((_code)) || {
      return "${_code}"
    }

    local _last_command_height="$(wc -l <<<"${_last_command}")"

    local -a _output_array=()
    _output_array+=(
        '---'
        "lines_history: [${_lineno} ${_bash_lineno[*]}]"
        "function_trace: [${FUNCNAME[*]}]"
        "exit_code: ${_code}"
    )

    [[ "${#BASH_SOURCE[@]}" -gt '1' ]] && {
        _output_array+=('source_trace:')
        for _item in "${BASH_SOURCE[@]}"; do
            _output_array+=("  - ${_item}")
        done
    } || {
        _output_array+=("source_trace: [${BASH_SOURCE[*]}]")
    }

    [[ "${_last_command_height}" -gt '1' ]] && {
        _output_array+=(
            'last_command: ->'
            "${_last_command}"
        )
    } || {
        _output_array+=("last_command: ${_last_command}")
    }

    _output_array+=('---')
    printf '%s\n' "${_output_array[@]}" >&2
    exit ${_code}
}