How to simplify packer's use?

[wbthomason]

How can we make packer simpler and easier to use?

[matu3ba]

1. FAQ: Backup recommendations. Some scripts below, but dotfiles should be simpler+faster (when one has git aliases configured).
2. Not sure, if feasible/useful: --dry option to check if installing works
3. Explain advantage of optional plugins
4. Simple reinstall script?!

[akinsho]

I recently happened on a cool way to use packer's cond, disable keys to solve some quite thorny plugin setup I wanted and was struck by how powerful some of the setup can be, but only discovered this after about 20mins of trying things out. I think packer's value is that it's quite a powerful tool but it isn't always immediately obvious how to use it.

I think the plugin might benefit from some specific intro/common use case examples for setting up plugins that could be show cased and explained in a wiki or in collapsible sections in the README.

I know that currently there is a block there of some potential ways to use packer but I wonder if that doesn't go into enough detail/explain enough the use cases for things. I think something like the following section but for a few different use cases/ this could also be added to the help docs

Conditional plugin installation example

If you want a plugin installed on one machine but not another you can specify this using packer's disable key. Any plugin that is disabled won't be installed.

use {"my-windows-plugin", disable = os.getenv('IS_WINDOWS') }

[matu3ba]

#!/usr/bin/env bash
# quick backup script to mess with nvim config
# this does not work with dotfiles

## backup all files except those defined in ExcludeArray
## files in ExcludeArray will not be touched
## all other files in nvim config are deleted before restoring

## USAGE: 1. in $NVIM_PATH:                   bash backup.sh
##        2. in $NVIM_PATH/$BACKUP_FOLDER:    bash restore.sh

#safer defaults https://bertvv.github.io/cheat-sheets/Bash.html
set -o errexit   # abort on nonzero exitstatus
set -o nounset   # abort on unbound variable
set -o pipefail  # don't hide errors within pipes

NVIM_PATH="${HOME}/.config/nvim"
BACKUP_FOLDER="backup"
RESTORE="restore.sh"
declare -a ExcludeArray=("backup.sh" "beta_software" "install" "list")

ExcludeArray+=(${BACKUP_FOLDER})
echo "excluding ${ExcludeArray[@]}"

if [ -f "${NVIM_PATH}/${BACKUP_FOLDER}" ]; then
  echo "backup folder can not be created, please remove \"${BACKUP_FOLDER}\""
  echo "exiting.."
  exit 0
fi
mkdir ${BACKUP_FOLDER}
cd "${NVIM_PATH}"
# get all files at top level, that are not in ExcludeArray
for i in *; do
  # how hard can it be to check in one line, if an element is in an array...
  # https://www.mybluelinux.com/bash-guide-to-bash-arrays/#bash_array_contains_a_value_exact_match
  if [[ ${ExcludeArray[@]} =~ (^|[[:space:]])"${i}"($|[[:space:]]) ]]; then
      echo "dont copy: ${i}"
  else
      echo "copy recu: ${i}"
      cp -r "${i}" "${NVIM_PATH}/${BACKUP_FOLDER}"
  fi
done

echo "generate restore commands.."
cd "${NVIM_PATH}/${BACKUP_FOLDER}"

cat > "${RESTORE}" <<EOL
#!/bin/bash
# execute this script with
EOL

printf "# bash " >> "${RESTORE}"
printf "${RESTORE}\n" >> "${RESTORE}"

cat >> "${RESTORE}" <<EOL
# if rm fails: stop nvim and delete nvim config with `rm -fr`
set -o errexit   # abort on nonzero exitstatus
set -o nounset   # abort on unbound variable
set -o pipefail  # don't hide errors within pipes
NVIM_PATH="\${HOME}/.config/nvim"
BACKUP_FOLDER="${BACKUP_FOLDER}"
RESTORE="${RESTORE}"
EOL

# metaprogramming in bash sucks due to missing reflection
printf "declare -a ExcludeArray=(" >> "${RESTORE}"
for i in "${ExcludeArray[@]}"; do
  printf "${i} " >> "${RESTORE}"
done
printf ")\n" >> "${RESTORE}"

cat >> "${RESTORE}" <<EOL
cd "\${NVIM_PATH}/"

# clean nvim config
for i in *; do
  if [[ \${ExcludeArray[@]} =~ (^|[[:space:]])"\${i}"(\$|[[:space:]]) ]]; then
      echo "dont remove: \${i}"
  else
      echo "remove recu: \${i}"
      rm -r "\${i}"
  fi
done
cd \${NVIM_PATH}/\${BACKUP_FOLDER}/
for i in *; do
  if [[ "\${i}" == "\${RESTORE}" ]]; then
    echo "dont copy \${i}"
    continue
  fi
  if [[ \${ExcludeArray[@]} =~ (^|[[:space:]])"\${i}"(\$|[[:space:]]) ]]; then
      echo "dont copy: \${i}"
  else
      echo "copy recu: \${i}"
      cp -r "\${NVIM_PATH}/\${BACKUP_FOLDER}/\${i}" "\${NVIM_PATH}/"
  fi
done
EOL

echo "done. have fun configuring nvim!"

[matu3ba]

bash handling of arrrays looks sadly quite distasteful.

[matu3ba]

#!/usr/bin/env bash
# reinstall fresh packer and clean all packages
# make sure to select correct location(s)

## Dont forget to close all neovim instances
## Manually deleting should not be necessary

mkdir -p "${HOME}/.local/share/nvim/site/pack/packer/opt"
mkdir -p "${HOME}/.local/share/nvim/site/pack/packer/start"

rm -r    "${HOME}/.local/share/nvim/site/pack/packer/start"
git clone https://github.com/wbthomason/packer.nvim "${HOME}/.local/share/nvim/site/pack/packer/start/packer.nvim"

#rm -r    "${HOME}/.local/share/nvim/site/pack/packer/opt"
#git clone https://github.com/wbthomason/packer.nvim "${HOME}/.local/share/nvim/site/pack/packer/opt/packer.nvim"