Add shell completions

.gitignore

@@ -7,3 +7,5 @@ logs
 
 # Ignore elvis escript
 elvis
+!priv/bash_completion/elvis
+!priv/zsh_completion/_elvis

README.md

@@ -46,6 +46,17 @@ i.e. `.bashrc`, `.zshrc`, ...)
 Now run it by calling `elvis` (or `elvis help`), and you should get to the `Usage: elvis`
 instructions.
 
+### Shell completion
+
+Elvis also comes with shell completions.
+
+Optionally, download and install:
+
+- Bash completion from <https://github.com/inaka/elvis/raw/master/priv/bash_completion/elvis>
+- Zsh completion from <https://github.com/inaka/elvis/master/priv/zsh_completion/_elvis>
+
+depending on your preferred shell.
+
 ## Usage
 
 The most common use case is to `cd` into a folder containing an `elvis.config` file

priv/bash_completion/elvis

@@ -0,0 +1,40 @@
+#!/bin/bash
+# shellcheck disable=SC2207  # Prefer mapfile or read -a to split command output (or quote to avoid splitting)
+
+# Bash completion for Elvis, the Erlang style reviewer
+_elvis() {
+  local cur prev
+  COMPREPLY=()
+  cur="${COMP_WORDS[COMP_CWORD]}"
+  prev="${COMP_WORDS[COMP_CWORD - 1]}"
+
+  if [[ ${prev} == "--config" ]] || [[ ${prev} == "rock" ]]; then
+    local files_and_dirs=($(compgen -f -- "${cur}"))
+    for item in "${files_and_dirs[@]}"; do
+      if [[ -d "${item}" ]]; then
+        compopt -o nospace
+        COMPREPLY+=("${item}/")
+      else
+        COMPREPLY+=("${item}")
+      fi
+    done
+    return 0
+  elif [[ ${prev} == "--code_path" ]]; then
+    compopt -o nospace
+    COMPREPLY=($(compgen -d -- "${cur}"))
+  elif [[ ${prev} == "install" ]]; then
+    COMPREPLY=($(compgen -W "git-hook" -- "${cur}"))
+  elif [[ ${prev} == "--output_format" ]]; then
+    COMPREPLY=($(compgen -W "plain colors parsable" -- "${cur}"))
+  elif [[ ${prev} == "--parallel" ]]; then
+    COMPREPLY=($(compgen -W "auto" -- "${cur}"))
+  elif [[ ${prev} == "git-branch" ]]; then
+    COMPREPLY=($(compgen -W "$(git branch --format='%(refname)' | sed 's|refs/heads/||' || true)" -- "${cur}"))
+  else
+    COMPREPLY=($(compgen -W '--help --config --commands git-branch git-hook install rock --output_format --parallel --quiet --verbose --version --code_path --keep_rocking' -- "${cur}"))
+  fi
+
+  return 0
+}
+
+complete -F _elvis elvis

priv/zsh_completion/_elvis

@@ -0,0 +1,63 @@
+#compdef elvis
+
+# Bash completion for Elvis, the Erlang style reviewer
+
+_elvis() {
+    local -a commands
+    local -a formats
+    local -a parallel_opts
+    local -a branches
+    local cur prev
+
+    cur="${1}"
+    prev="${2}"
+
+    commands=(
+        '--help[Show help information]'
+        '--config[Provide path to a non-default configuration file]'
+        '--commands[Show available commands]'
+        'git-branch[Execute on files changed since <branch> or <commit>]'
+        'git-hook[Execute on the pre-commit hook Git-staged files]'
+        'install[Install as a Git pre-commit hook]'
+        'rock[Execute on identified files]'
+        '--output_format[Control the output format]'
+        '--parallel[Analyze files concurrently]'
+        '--quiet[Suppress all output]'
+        '--verbose[Enable verbose output]'
+        '--version[Show the current version]'
+        '--code_path[Add <dir> to analysis code path]'
+        '--keep_rocking[Don’t stop on errors]'
+    )
+
+    formats=(
+        'plain[Plain text output]'
+        'colors[Colored output]'
+        'parsable[Output suitable for parsing]'
+    )
+
+    parallel_opts=(
+        'auto[Automatically determine parallelism]'
+        'n[Specify number of parallel processes]'
+    )
+
+    if [[ "$prev" == "--config" ]]; then
+        _files
+    elif [[ "$prev" == "--code_path" ]]; then
+        _files -d
+    elif [[ "$prev" == "--output_format" ]]; then
+        _describe -t formats
+    elif [[ "$prev" == "--parallel" ]]; then
+        _describe -t parallel 'Parallel options' parallel_opts
+    elif [[ "$prev" == "git-branch" ]]; then
+        branches=($(git branch --format='%(refname)' | sed 's|refs/heads/||' || true))
+        _describe -t branches 'Git branches' branches
+    elif [[ "$prev" == "install" ]]; then
+        _describe -t install 'Install commands' 'git-hook'
+    elif [[ "$prev" == "rock" ]]; then
+        _files
+    else
+        _describe -t commands 'elvis commands' commands
+    fi
+}
+
+compdef _elvis elvis