test_plugin.sh

#!/usr/bin/env bash

# See: ./test_plugin.sh --help

function fail() {
  echo "FAIL: $*" >&2
  exit 1
}

# Extract the link to a svg badge from a line of README.
function badge_svg() {
  grep -o '(http[^)]*svg[^)]*)' | sed -e 's/(//;s/)//'
}

function check_plugin_from_diff() {
  local BASE_REF="$1" # Base commit of main branch.
  local HEAD_REF="$2" # Latest commit of PR

  local DIFF_CHANGES
  DIFF_CHANGES="$(git diff --name-only "${BASE_REF}" "${HEAD_REF}")"

  # Assert that the PR diff only includes a change to README and a file under plugins/
  {
    test "2" == "$(echo "$DIFF_CHANGES" | wc -l | xargs)" &&
      echo "$DIFF_CHANGES" | grep README.md >/dev/null &&
      echo "$DIFF_CHANGES" | grep plugins/ >/dev/null
  } || fail "Expected git diff ${REF_RANGE} to only include changes for a single plugin"

  local PLUGIN_FILE
  PLUGIN_FILE="$(git diff --name-only "${BASE_REF}" "${HEAD_REF}" -- plugins/)"

  check_plugin_from_file "$PLUGIN_FILE"
}

function check_plugin_from_file() {
  local PLUGIN_FILE="$1"
  echo "Checking $PLUGIN_FILE"

  # Assert that we have a file at plugins/PLUGIN_NAME
  test -f "$PLUGIN_FILE" ||
    fail "Expected a plugin file at $PLUGIN_FILE"

  # Assert that PLUGIN_FILE file ends with new line.
  test 'X' == "$(tail -c1 "$PLUGIN_FILE" | tr '\n' 'X')" ||
    fail "Expected $PLUGIN_FILE to end with a new line."

  # Assert that PLUGIN_FILE has repository key and points to a git repo.
  local PLUGIN_REPO
  PLUGIN_REPO="$(sed -e 's/repository = //' "$PLUGIN_FILE")"
  test -n "$PLUGIN_REPO" ||
    fail "File $PLUGIN_FILE does not specify a repository url"

  # Assert the plugin repo is reachable.
  git ls-remote -q "$PLUGIN_REPO" HEAD >/dev/null ||
    fail "Repo is unreachable: $PLUGIN_REPO"

  local PLUGIN_REPO_NO_GIT
  PLUGIN_REPO_NO_GIT="$(echo "$PLUGIN_REPO" | sed -e 's/\.git$//' | tr '/' '\n' | tail -n1)"

  local README_LINE
  README_LINE="$(git grep -h -C0 "${PLUGIN_REPO_NO_GIT}" -- README.md | head -n 1)"

  # Assert that a new line for plugin was added at README
  test -n "$README_LINE" ||
    fail "Expected a line at README.md with a link to ${PLUGIN_REPO_NO_GIT}"

  BADGE_COLUMN="$(echo "${README_LINE}" | cut -d'|' -f4)"
  BADGE_URL="$(echo "${BADGE_COLUMN}" | badge_svg)"

  # Assert that the badge has "pass" text in it, indicating the plugin is healthy
  curl -qsL "${BADGE_URL}" | grep -o -i 'pass' >/dev/null ||
    fail "Expected plugin CI badge SVG to be passing but it was not: $BADGE_URL"

  echo "OK $PLUGIN_FILE"
}

function check_all_plugins() {
  local fails=0
  local total=0
  local out
  for file in plugins/*; do
    total=$((total + 1))
    echo -n "* Checking $file"
    out="$($0 --file "$file" 2>&1)"
    if test $? == 0; then
      echo " [PASSED]"
    else
      fails=$((fails + 1))
      echo " [FAILED]"
      echo "Failure:  $out"
    fi
  done

  echo
  echo "Plugins available: ${total}"
  echo "Plugin build checks passed: $((total - fails))"
  echo "Plugin build checks failed: ${fails}"
  exit ${fails}
}

if test "--all" == "$*"; then
  echo "Testing all registered plugins"
  check_all_plugins

elif test "--diff" == "$1"; then
  echo "Testing plugin introduced at git diff $2..$3"
  check_plugin_from_diff "$2" "$3"

elif test "--file" == "$1"; then
  check_plugin_from_file "$2"
else
  cat <<-EOF
Test that a plugin at PLUGIN_FILE follows basic sanity checks:
  * A plugins/<plugin> file contains the repository url.
  * A new line is added on README.md with a link mentioning the plugin.
  * The new plugin has CI badge and it's passing.

Usage:

> $0 --file plugins/PLUGIN_FILE
    Test only plugin at file.

> $0 --all
    Test all plugins registered under plugins/

> $0 --diff BASE_REF HEAD_REF
    Test a single plugin introduced in git diff BASE_REF..HEAD_REF
EOF
fi