tools/devshell/contrib/coverage

#!/usr/bin/env bash
# Copyright 2022 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

#### CATEGORY=Test
#### PREBUILTS=${PREBUILT_CLANG_DIR} ${PREBUILT_PYTHON3}
### Runs test and exports coverage data.

## usage: fx coverage [--lcov-output-path <path>] [--html-output-dir <directory>] [--json-output-path <path>] [--include-filename-regex <pattern>] [--ignore-filename-regex <pattern>] [--test-output-dir <directory>] [-v|--verbose] [-h|--help] [testName ...]
##
## Runs test and exports coverage data.
##
## --html-output-dir: directory to output test coverage HTML to
## --lcov-output-path: path to write output lcov to
## --json-output-path: path to write output JSON to
## --include-filename-regex: regex pattern to only include matching source files
## --ignore-filename-regex: regex pattern to skip matching source files
## --test-output-dir: directory to use as test output, skipping running fx test
## -v|--verbose: print all executed commands for debugging
## -h|--help: prints help message

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/../lib/vars.sh || exit $?
fx-config-read

# Turn on checking after reading config. Otherwise unbound variables in the config read
# can cause the script to fail.
set -euo pipefail

function main() {
  local lcov_output_path=''
  local html_output_dir=''
  local json_output_path=''
  local include_filename_regex=''
  local ignore_filename_regex=''
  local verbose=false
  local test_output_dir=''
  local ffx_cov_args=()

  while [[ $# -ge 1 ]]; do
    case "$1" in
      --lcov-output-path)
        shift
        # Get absolute path because `ffx coverage` is executed in a different
        # dir.
        lcov_output_path="$(realpath ${1})"
        ;;
      --html-output-dir)
        shift
        # Get absolute path because `ffx coverage` is executed in a different
        # dir.
        html_output_dir="$(realpath ${1})"
        ;;
      --json-output-path)
        shift
        # Create directory if it doesn't exist so realpath succeeds.
        local json_dir="$(dirname "${1}")"
        if [[ ! -d "${json_dir}" ]]; then
          mkdir -p "${json_dir}"
        fi
        # Get absolute path because `ffx coverage` is executed in a different
        # dir.
        json_output_path="$(realpath "${1}")"
        ;;
      --include-filename-regex)
        shift
        include_filename_regex="${1}"
        ;;
      --ignore-filename-regex)
        shift
        ignore_filename_regex="${1}"
        ;;
      --test-output-dir)
        shift
        test_output_dir="$(realpath ${1})"
        ;;
      -v|--verbose)
        verbose=true
        ;;
      -h|--help)
        fx-command-help
        exit 0
        ;;
      *)
        break
        ;;
    esac
    shift
  done

  if [[ -z "${test_output_dir}" ]]; then
    test_output_dir="$(mktemp -d)"
    trap "rm -rf ${test_output_dir}" EXIT

    echo "Running tests to collect coverage data ..."

    # Prevent ambient host tools (dldist, ffx, etc.) from emitting .profraw files into the current
    # working directory.
    export LLVM_PROFILE_FILE=/dev/null

    # %p = Process ID, %m = LLVM binary signature (prevents file collisions during parallel runs).
    # Pass via --env so that `fx test` propagates it to the actual host test subprocesses.
    fx-command-run test --no-timestamp-artifacts \
      --env "LLVM_PROFILE_FILE=${test_output_dir}/%p-%m.profraw" \
      --ffx-output-directory "${test_output_dir}" "${@}"
  else
    echo "Using existing test output directory: ${test_output_dir}"
  fi

  # Ensure debug symbols for pure Bazel tests are registered into .build-id/ before exporting coverage.
  "${PREBUILT_PYTHON3}" "${FUCHSIA_DIR}/build/bazel/scripts/copy_bazel_debug_symbols.py" "${FUCHSIA_BUILD_DIR}" 2>/dev/null || true

  # Check if any .profraw files were generated before invoking ffx coverage.
  if [[ -z "$(find "${test_output_dir}" -name "*.profraw" -print -quit)" ]]; then
    fx-warn "No coverage profile (.profraw) files found in ${test_output_dir}"
    fx-info "Ensure the test target was built with a coverage variant enabled:"
    fx-info "  - Fuchsia component tests: --variant coverage"
    fx-info "  - Host tests: --variant host_coverage"
    if [[ -f "${FUCHSIA_BUILD_DIR}/args.gn" ]] && ! grep -q "host_coverage" "${FUCHSIA_BUILD_DIR}/args.gn"; then
      if grep -q "coverage" "${FUCHSIA_BUILD_DIR}/args.gn"; then
        fx-info "Note: ${FUCHSIA_BUILD_DIR}/args.gn enables 'coverage' (Fuchsia target only), which does not instrument host tests."
      else
        fx-info "Note: No coverage variant was found in ${FUCHSIA_BUILD_DIR}/args.gn."
      fi
    fi
    fx-info "See //docs/contribute/testing/coverage.md for details."
    exit 1
  fi

  if [[ -n "$(find "${test_output_dir}" -name "*.profdata" -print -quit)" ]]; then
    fx-warn "Unexpected coverage profile (.profdata) files found in ${test_output_dir}"
    fx-info "Ensure no coverage profiles were generated by other processes."
    exit 1
  fi

  echo "Exporting coverage data ..."

  if [[ -n "${lcov_output_path}" ]]; then
    ffx_cov_args+=("--export-lcov" "${lcov_output_path}")
  fi
  if [[ -n "${html_output_dir}" ]]; then
    ffx_cov_args+=("--export-html" "${html_output_dir}")
  fi
  if [[ -n "${json_output_path}" ]]; then
    ffx_cov_args+=("--export-json" "${json_output_path}")
  fi
  if [[ -n "${include_filename_regex}" ]]; then
    ffx_cov_args+=("--include-filename-regex" "${include_filename_regex}")
  fi
  if [[ -n "${ignore_filename_regex}" ]]; then
    ffx_cov_args+=("--ignore-filename-regex" "${ignore_filename_regex}")
  fi
  if [[ ${verbose} == true ]]; then
    ffx_cov_args+=("--verbose")
  fi

  # TODO(https://fxbug.dev/42054992): realpath is not available on Mac, use a
  # platform-neutral implementation instead.
  readonly _REL_BUILD_DIR="$(realpath -s --relative-to="${FUCHSIA_BUILD_DIR}" "${FUCHSIA_DIR}")"

  readonly start_time=$SECONDS
  fx-command-run host-tool ffx-coverage \
    coverage \
    --clang-dir "${PREBUILT_CLANG_DIR}" \
    --symbol-index-json "${FUCHSIA_BUILD_DIR}/.symbol-index.json" \
    --test-output-dir "${test_output_dir}" \
    ${ffx_cov_args[@]+"${ffx_cov_args[@]}"} \
    --path-remappings "${_REL_BUILD_DIR},${FUCHSIA_DIR}" \
    --compilation-dir "${FUCHSIA_BUILD_DIR}"
  readonly duration=$((SECONDS - start_time))
  echo "Coverage exported in ${duration} seconds."

  if [[ -n "${lcov_output_path}" ]]; then
    echo "Coverage LCOV exported to ${lcov_output_path}"
  fi
  if [[ -n "${html_output_dir}" ]]; then
    echo "Coverage HTML exported to ${html_output_dir}"
  fi
  if [[ -n "${json_output_path}" ]]; then
    echo "Coverage JSON exported to ${json_output_path}"
  fi
}

main $@