#!/bin/bash
# Generate test coverage statistics for Go packages.
#
# Works around the fact that `go test -coverprofile` currently does not work
# with multiple packages, see https://code.google.com/p/go/issues/detail?id=6909
#
# Usage: coverage.sh [--html|--coveralls]
#
#     --html      Additionally create HTML report
#     --coveralls Push coverage statistics to coveralls.io
#

set -e

workdir=.cover
profile="$workdir/cover.out"
mode=count

generate_cover_data() {
    rm -rf "$workdir"
    mkdir "$workdir"

    for pkg in "$@"; do
        f="$workdir/$(echo $pkg | tr / -).cover"
        go test -covermode="$mode" -coverprofile="$f" "$pkg"
    done

    echo "mode: $mode" >"$profile"
    grep -h -v "^mode:" "$workdir"/*.cover >>"$profile"
}

show_html_report() {
    go tool cover -html="$profile" -o="$workdir"/coverage.html
}

show_csv_report() {
    go tool cover -func="$profile" -o="$workdir"/coverage.csv
}

push_to_coveralls() {
    echo "Pushing coverage statistics to coveralls.io"
    echo $GOPATH
    # ignore failure to push - it happens
    goveralls -coverprofile="$profile" \
                          -service=github || true
}

generate_cover_data $(go list ./... | grep -v /vendor/)
show_csv_report

case "$1" in
"")
    ;;
--html)
    show_html_report ;;
--coveralls)
    push_to_coveralls ;;
*)
    echo >&2 "error: invalid option: $1"; exit 1 ;;
esac