Helper functions for rust development

README.md

Helper functions for rust development

These are helper functions for rust development inspired by Jeremy Chones cwt and cwe helper functions (however I call them rwt and rwe). They start examples or tests and watch them with bacon. This is nice when exploring in examples or doing a kind of test driven development.

These are best if you have fzf, bacon and bat installed but should also work with just bacon (that is needed and recommended, as cargo-watch is unmaintained). Add the function declarations in rust_helpers.bash to your initialization files (e.g. ~/.bashrc). To also get autocompletion for them, create files ~/.local/share/bash-completion/completions/{rwe,rwt} and add the contents of rwe_completion.bash and rwt_completion.bash. Note that the completion files have no file extension. I added an extension here so that the gist renders more nicely.

Just call rwe or rwt to see the fzf window. For examples it should also display a preview of the code. Select a test or example and press enter to watch it.

One disclaimer about the autocompletion of rwt. It works best when typing rwt ", since test names are fully qualified and contain :: (double colons).

Preview

Selection:

While running:

rust_helpers.bash

# watch examples with bacon
rwe() {
  if ! command -v bacon >/dev/null 2>&1; then
    echo "Error: \`bacon\` command not found." >&2
    return 1
  fi
  case $# in
  0)
    if ! command -v fzf >/dev/null 2>&1 || [ ! -d "examples" ]; then
      echo "Usage: rwe <example_name>" >&2
      [ ! -d "examples" ] && echo "Error: 'examples/' directory not found." >&2
      ! command -v fzf >/dev/null 2>&1 && echo "Tip: Install 'fzf' for interactive selection." >&2
      return 1
    fi
    local selected
    selected=$(find examples -name "*.rs" -type f 2>/dev/null |
      while IFS= read -r file; do
        local name="${file#examples/}"
        name="${name%.rs}"
        [[ "$name" == */main ]] && name="${name%/main}"
        echo -e "$name\t$file"
      done |
      sort -u |
      fzf --prompt="Select example: " \
        --header="Select an example to run" \
        --delimiter=$'\t' \
        --with-nth=1 \
        --preview='bat --color=always {2} 2>/dev/null || cat {2}' \
        --preview-window=right:60%)
    if [ -n "$selected" ]; then
      local example_name="${selected%%$'\t'*}"
      echo "Running example: $example_name"
      bacon run -- -q --example "$example_name"
    fi
    ;;
  1)
    bacon run -- -q --example "$1"
    ;;
  *)
    echo "Error: Too many arguments." >&2
    echo "Usage: rwe <example_name>" >&2
    return 1
    ;;
  esac
}

# watch tests with bacon (and preserve output)
rwt() {
  if ! command -v bacon >/dev/null 2>&1; then
    echo "Error: \`bacon\` not found." >&2
    return 1
  fi
  case $# in
  0)
    if command -v fzf >/dev/null 2>&1; then
      local selected
      selected=$(cargo test -q -- --list 2>/dev/null |
        grep ': test$' |
        sed 's/: test$//' |
        fzf \
          --prompt="Select test: " \
          --header="Enter to run" \
          --preview="echo 'Selected test:'; echo '---'; echo {}" \
          --preview-window=up:30%)
      if [ -n "$selected" ]; then
        echo "Running: $selected"
        bacon test -- "$selected" -- --nocapture
      fi
    else
      echo "Usage: rwt [test_file] <test_filter>" >&2
      echo "Tip: Install fzf for interactive test selection" >&2
      return 1
    fi
    ;;
  1) bacon test -- "$1" -- --nocapture ;;
  2) bacon test -- --test "$1" -- "$2" -- --nocapture ;;
  *)
    echo "Usage: rwt [test_file] <test_filter>" >&2
    return 1
    ;;
  esac
}

rwe_completion.bash

_rwe() {
  local cur="${COMP_WORDS[COMP_CWORD]}"
  if [ "$COMP_CWORD" -eq 1 ]; then
    local examples=""
    if [ -d examples ]; then
      while IFS= read -r -d '' file; do
        local rel_path="${file#examples/}"
        local name="${rel_path%.rs}"
        [[ "$name" == */main ]] && name="${name%/main}"
        examples="$examples $name"
      done < <(find examples -name "*.rs" -type f -print0 2>/dev/null)
    fi
    if [ -n "$examples" ]; then
      mapfile -t COMPREPLY < <(compgen -W "$examples" -- "$cur")
    fi
  fi
}
complete -F _rwe rwe

rwt_completion.bash

_rwt() {
  local cur="${COMP_WORDS[COMP_CWORD]}"
  case "$COMP_CWORD" in
  1)
    local tests=""
    if [ -d tests ]; then
      tests=$(find tests -name "*.rs" -type f 2>/dev/null |
        sed 's|.*/||; s|\.rs$||' | grep -v '^common$')
    fi
    if command -v cargo >/dev/null 2>&1; then
      local test_names
      test_names=$(cargo test -q -- --list 2>/dev/null |
        grep '^[a-z_]' | sed 's/: .*//')
      tests="$tests $test_names"
    fi
    if [ -n "$tests" ]; then
      mapfile -t COMPREPLY < <(compgen -W "$tests" -- "$cur")
    fi
    ;;
  2)
    local test_file="${COMP_WORDS[1]}"
    if command -v cargo >/dev/null 2>&1; then
      local test_names
      test_names=$(cargo test -q --test "$test_file" -- --list 2>/dev/null |
        grep '^[a-z_]' | sed 's/: .*//')
      if [ -n "$test_names" ]; then
        mapfile -t COMPREPLY < <(compgen -W "$test_names" -- "$cur")
      fi
    fi
    ;;
  esac
}
complete -F _rwt rwt