add snippet for coverage collection

#!/usr/bin/env bash

set -euo pipefail

usage() {

  cat <<'EOF'

Usage: coverage_cli.sh --obj-dir DIR --output-file FILE --output-dir DIR --title STRING

Generates lcov coverage, removes "apps" and "lib_util" from coverage, normalizes paths,

and produces an HTML report with a title.

Required arguments:

  --obj-dir       Directory containing object files (.gcno/.gcda)

  --output-file   Path to lcov tracefile (.info)

  --output-dir    Directory to write HTML report

  --title         Title suffix for HTML report

EOF

}

obj_dir=""

output_file=""

output_dir=""

title=""

# Parse arguments

while [[ $# -gt 0 ]]; do

  case "$1" in

  --obj-dir)

    obj_dir="${2:-}"

    shift 2

    ;;

  --output-file)

    output_file="${2:-}"

    shift 2

    ;;

  --output-dir)

    output_dir="${2:-}"

    shift 2

    ;;

  --title)

    title="${2:-}"

    shift 2

    ;;

  -h | --help)

    usage

    exit 0

    ;;

  *)

    echo "Unknown option: $1" >&2

    usage

    exit 1

    ;;

  esac

done

# Validate required args

if [[ -z "$obj_dir" || -z "$output_file" || -z "$output_dir" || -z "$title" ]]; then

  echo "Error: missing required arguments." >&2

  usage

  exit 1

fi

# Capture coverage

lcov -c -d "$obj_dir" -o "$output_file"

# Remove apps and lib_util files from coverage

lcov -r "$output_file" "*apps*" -o "$output_file"

lcov -r "$output_file" "*lib_util*" -o "$output_file"

commit_sha="$(git rev-parse HEAD)"

# Replace absolute path with '.' to ease merging of .info files (assumes GNU sed)

sed -i "s|$(pwd)|.|g" "$output_file"

# Generate HTML report

genhtml "$output_file" -o "$output_dir" -t "$title @ $commit_sha"