error-prone-support/integration-tests/checkstyle.sh

#!/usr/bin/env bash

set -e -u -o pipefail

integration_test_root="$(readlink -f "$(dirname "${0}")")"
error_prone_support_root="${integration_test_root}/.."
repos_root="${integration_test_root}/.repos"

test_name="$(basename "${0}" .sh)"
project=checkstyle
repository=https://github.com/checkstyle/checkstyle.git
revision=checkstyle-10.13.0

if [ "${#}" -gt 2 ] || ([ "${#}" = 2 ] && [ "${1:---sync}" != '--sync' ]); then
  echo "Usage: ${0} [--sync] [<report_directory>]"
  exit 1
fi
do_sync="$([ "${#}" = 0 ] || [ "${1:-}" != '--sync' ] || echo 1)"
report_directory="$([ "${#}" = 0 ] || ([ -z "${do_sync}" ] && echo "${1}") || ([ "${#}" = 1 ] || echo "${2}"))"

if [ -n "${report_directory}" ]; then
  mkdir -p "${report_directory}"
else
  report_directory="$(mktemp -d)"
  trap 'rm -rf -- "${report_directory}"' INT TERM HUP EXIT
fi

# XXX: Configure Renovate to manage the AssertJ version declared here.
shared_build_flags="
  -Perror-prone-compile,error-prone-test-compile
  -Dassertj.version=3.24.2
  -Derror-prone.version=$(
    mvn -f "${error_prone_support_root}" help:evaluate -Dexpression=version.error-prone -q -DforceStdout
  )
  -Derror-prone-support.version=$(
    mvn -f "${error_prone_support_root}" help:evaluate -Dexpression=project.version -q -DforceStdout
  )
  -DadditionalSourceDirectories=\${project.basedir}\${file.separator}src\${file.separator}it\${file.separator}java,\${project.basedir}\${file.separator}src\${file.separator}xdocs-examples\${file.separator}java
  "

# XXX: Configure Renovate to manage the fmt-maven-plugin version declared here.
# XXX: Once GitHub actions uses Maven 3.9.2+, we can inline this variable with
# version reference `${fmt.version}`, and `-Dfmt.version=2.21.1` added to
# `shared_build_flags`.
format_goal='com.spotify.fmt:fmt-maven-plugin:2.21.1:format'

error_prone_shared_flags='-XepExcludedPaths:(\Q${project.basedir}${file.separator}src${file.separator}\E(it|test|xdocs-examples)\Q${file.separator}resources\E|\Q${project.build.directory}${file.separator}\E).*'

# XXX: Drop the `ErrorProneRuntimeClasspath` exclusion once that check resides
# in a separate Maven module.
error_prone_patch_flags="${error_prone_shared_flags} -XepPatchLocation:IN_PLACE -XepPatchChecks:$(
  find "${error_prone_support_root}" -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" -print0 \
    | xargs -0 grep -hoP '[^.]+$' \
    | grep -v ErrorProneRuntimeClasspath \
    | paste -s -d ','
)"

# XXX: Drop the `ErrorProneRuntimeClasspath` exclusion once that check resides
# in a separate Maven module.
error_prone_validation_flags="${error_prone_shared_flags} -XepDisableAllChecks $(
  find "${error_prone_support_root}" -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" -print0 \
    | xargs -0 grep -hoP '[^.]+$' \
    | sed -r 's,(.*),-Xep:\1:WARN,' \
    | grep -v ErrorProneRuntimeClasspath \
    | paste -s -d ' '
)"

echo "Shared build flags: ${shared_build_flags}"
echo "Error Prone patch flags: ${error_prone_patch_flags}"
echo "Error Prone validation flags: ${error_prone_validation_flags}"

mkdir -p "${repos_root}"

# Make sure that the targeted tag of the project's Git repository is checked
# out.
project_root="${repos_root}/${project}"
if [ ! -d "${project_root}" ]; then
  # The repository has not yet been cloned; create a shallow clone.
  git clone --branch "${revision}" --depth 1 "${repository}" "${project_root}"
else
  # The repository does already appear to exist. Try to check out the requested
  # tag if possible, and fetch it otherwise.
  #
  # Under certain circumstances this does not cause the relevant tag to be
  # created, so if necessary we manually create it.
  git -C "${project_root}" checkout --force "${revision}" 2>/dev/null \
    || (
         git -C "${project_root}" fetch --depth 1 "${repository}" "${revision}" \
           && git -C "${project_root}" checkout --force FETCH_HEAD \
           && (git -C "${project_root}" tag "${revision}" || true)
       )
fi

pushd "${project_root}"

# Make sure that Git is sufficiently configured to enable committing to the
# project's Git repository.
git config user.email || git config user.email "integration-test@example.com"
git config user.name || git config user.name "Integration Test"

# Prepare the code for analysis by (a) applying the minimal set of changes
# required to run Error Prone with Error Prone Support and (b) formatting the
# code using the same method by which it will be formatted after each
# compilation round. The initial formatting operation ensures that subsequent
# modifications can be rendered in a clean manner.
git clean -fdx
git apply < "${integration_test_root}/${test_name}-init.patch"
git commit -m 'dependency: Introduce Error Prone Support' .
mvn ${shared_build_flags} "${format_goal}"
git commit -m 'minor: Reformat using Google Java Format' .
diff_base="$(git rev-parse HEAD)"

# Apply Error Prone Support-suggested changes until a fixed point is reached.
function apply_patch() {
  local extra_build_args="${1}"

  mvn ${shared_build_flags} ${extra_build_args} \
    package "${format_goal}" \
    -Derror-prone.configuration-args="${error_prone_patch_flags}" \
    -DskipTests

  if ! git diff --exit-code; then
    git commit -m 'minor: Apply patches' .

    # Changes were applied, so another compilation round may apply yet more
    # changes. For performance reasons we perform incremental compilation,
    # enabled using a misleading flag. (See
    # https://issues.apache.org/jira/browse/MCOMPILER-209 for details.)
    apply_patch '-Dmaven.compiler.useIncrementalCompilation=false'
  elif [ "${extra_build_args}" != 'clean' ]; then
    # No changes were applied. We'll attempt one more round in which all files
    # are recompiled, because there are cases in which violations are missed
    # during incremental compilation.
    apply_patch 'clean'
  fi
}
apply_patch ''

# Run one more full build and log the output.
#
# By also running the tests, we validate that the (majority of) applied changes
# are behavior preserving. Some tests are skipped:
# - The `metadataFilesGenerationAllFiles` test is skipped because it makes line
#   number assertions that will fail when the code is formatted or patched.
# - The `allCheckSectionJavaDocs` test is skipped because is validates that
#   Javadoc has certain closing tags that are removed by Google Java Format.
validation_build_log="${report_directory}/${test_name}-validation-build-log.txt"
mvn ${shared_build_flags} \
      clean package \
      -Derror-prone.configuration-args="${error_prone_validation_flags}" \
      -Dtest='
        !MetadataGeneratorUtilTest#metadataFilesGenerationAllFiles,
        !XdocsJavaDocsTest#allCheckSectionJavaDocs' \
    | tee "${validation_build_log}" \
  || failure=1

# Collect the applied changes.
expected_changes="${integration_test_root}/${test_name}-expected-changes.patch"
actual_changes="${report_directory}/${test_name}-changes.patch"
(git diff "${diff_base}"..HEAD | grep -vP '^(diff|index)' || true) > "${actual_changes}"

# Collect the warnings reported by Error Prone Support checks.
expected_warnings="${integration_test_root}/${test_name}-expected-warnings.txt"
actual_warnings="${report_directory}/${test_name}-validation-build-warnings.txt"
(grep -oP "(?<=^\\Q[WARNING] ${PWD}/\\E).*" "${validation_build_log}" | grep -P '\] \[' || true) | LC_ALL=C sort > "${actual_warnings}"

# Persist or validate the applied changes and reported warnings.
if [ -n "${do_sync}" ]; then
  echo 'Saving changes...'
  cp "${actual_changes}" "${expected_changes}"
  cp "${actual_warnings}" "${expected_warnings}"
else
  echo 'Inspecting changes...'
  # XXX: This "diff of diffs" also contains vacuous sections, introduced due to
  # line offset differences. Try to omit those from the final output.
  if ! diff -u "${expected_changes}" "${actual_changes}"; then
    echo 'There are unexpected changes.'
    failure=1
  fi
  echo 'Inspecting emitted warnings...'
  if ! diff -u "${expected_warnings}" "${actual_warnings}"; then
    echo 'Diagnostics output changed.'
    failure=1
  fi
fi

if [ -n "${failure:-}" ]; then
  exit 1
fi