#!/bin/bash
# Checks that the "_svn" function defined in the specified "bash_completion"
# script produces appropriate lists of completions for various incomplete svn
# command lines.

if [ ! -f "$1" ] || [ "$2" ]; then
  echo "Usage: bash_completion_test BASH_COMPLETION_PATHNAME"
  echo "Tests the specified \"bash_completion\" script,"
  echo "including checking it against the \"svn\" program found in the current PATH."
  exit 1
fi

set -e  # Exit on error
shopt -s extglob

# Execute the script which is to be tested.
. "$1"

# From the given incomplete svn command, print a space-separated list of
# possible completions of the last argument (or of an empty first argument
# if no subcommand is given).
# Usage: get_svn_completions [SVN-SUBCOMMAND [SVN-OPTION...]]
get_svn_completions() {
  COMP_WORDS=(svn "$@")
  if [ $# == 0 ]; then
    COMP_CWORD=1
  else
    COMP_CWORD=$#
  fi
  _svn
  echo -n "${COMPREPLY[*]}"
}

# Print a failure message, record the failure, and return "false".
# Usage: fail MESSAGE
fail() {
  PREFIX="FAIL: "
  for LINE in "$@"; do
    echo "$PREFIX$LINE"
    PREFIX="      "
  done
  TESTS_FAILED=1
  false
}

# Check that EXPECTED-WORD is among the completions of the last word in
# SVN-COMMAND.  SVN-COMMAND is a single argument to this function, split
# into multiple arguments when passed to "get_svn_completions()".
# Usage: includes SVN-COMMAND EXPECTED-WORD
includes() {
  COMPLETIONS=`get_svn_completions $1`
  if [[ "$2" != @(${COMPLETIONS// /|}) ]]; then
    fail "completions of \"svn $1\" should include \"$2\"" \
      "(completions: $COMPLETIONS)"
  fi
}

excludes() {
  COMPLETIONS=`get_svn_completions $1`
  if [[ "$2" == @(${COMPLETIONS// /|}) ]]; then
    fail "completions of \"svn $1\" should exclude \"$2\"" \
      "(completions: $COMPLETIONS)"
  fi
}

# Print the valid subcommands for "svn", one per line, sorted.
# Exclude any synonym that is just a truncation of its full name.
# Usage: get_svn_subcommands
get_svn_subcommands() {
  svn help |
    # Find the relevant lines.
    sed -n -e '1,/^Available subcommands:$/d;/^$/q;p' |
    # Remove brackets and commas
    tr -d ' )' | tr '(,' ' ' |
    # Remove simple abbreviations
    ( while read SYNONYMS; do
        for CMD in $SYNONYMS; do
          for SYNONYM in $SYNONYMS; do
            if [ $CMD != "?" ]; then
              case $SYNONYM in
              $CMD) ;;
              $CMD*) CMD= ; break ;;
              esac
            fi
          done
          if [ $CMD ]; then
            echo $CMD
          fi
        done
      done
    ) |
    sort
}

# Print the valid option switches for "svn SUBCMD", one per line, sorted.
# Usage: get_svn_options SUBCMD
get_svn_options() {
  { svn help "$1" |
      # Find the relevant lines; remove "arg" and description.
      sed -n -e '1,/^Valid options:$/d;/^  -/!d' \
             -e 's/\( arg\)* * : .*//;p' |
      # Remove brackets; put each word on its own line.
      tr -d '] ' | tr '[' '\n'
    # The following options are always accepted but not listed in the help
    echo "-h"
    echo "--help"
  } | sort
  
}


# The tests.
set +e  # Do not exit on error
TESTS_FAILED=

echo "Checking general completion"
includes "he" "help"
includes "" "?"
includes "" "h"
includes "" "help"
includes "" "--version"

echo "Checking list of subcommands"
HELP_SUBCMDS=`get_svn_subcommands | tr "\n" " "`
COMPLETION_SUBCMDS=`get_svn_completions | tr " " "\n" | grep -v "^-" | sort | tr "\n" " "`
if [ "$HELP_SUBCMDS" != "$COMPLETION_SUBCMDS" ]; then
  fail "non-option completions for \"svn \" != subcommands accepted" \
       "    (non-o. cmpl.: $COMPLETION_SUBCMDS)" \
       "    (svn accepts:  $HELP_SUBCMDS)"
fi

echo "Checking list of options for each subcommand"
for SUBCMD in $HELP_SUBCMDS; do
  HELP_OPTIONS=`get_svn_options $SUBCMD | tr "\n" " "`
  COMPLETION_OPTIONS=`get_svn_completions $SUBCMD - | tr " " "\n" | sort | tr "\n" " "`
  if [ "$HELP_OPTIONS" != "$COMPLETION_OPTIONS" ]; then
    fail "completions for \"svn $SUBCMD -\" != options accepted" \
	 "    (completions: $COMPLETION_OPTIONS)" \
         "    (svn accepts: $HELP_OPTIONS)"
  fi
done

echo "Checking rejection of synonyms"
excludes "diff -x -u -" "-x"
excludes "diff -x -u --e" "--extensions"
excludes "diff --extensions -u -" "--extensions"
excludes "diff --extensions -u -" "-x"
excludes "diff --extensions=-u -" "-x"

if [ $TESTS_FAILED ]; then
  echo "FAILURE: at least one bash_completion test failed."
else
  echo "All bash_completion tests passed."
fi