Creates a code coverage bash with bash "only"

makeCoverageBadge.sh

#!/bin/bash

#
# Creates a coverage badge svg with bash "only"
# Intent is to create a coverage badge in a travis job and uploading it to S3 so it can be displayed in a projects readme
#
# Uses: bash, read, cut, sed
#
# Usage: makeCoverageBadge.sh percent target_svg
# Example: makeCoverageBadge.sh 81.83 coverage.svg
#
#
#
# License:
# The badge template is based on the shields.io badges and are licensed under a CC0 License
# https://github.com/badges/shields/blob/master/LICENSE.md
#
# This script itself may be used and altered as pleased.
#

COVERAGE=$1 # Coverage in percent with two decimals: 81.34
OUTPUT=$2 # Name/Location of the svg

read -r -d '' TEMPLATE << EOM
<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="114" height="20">
   <linearGradient id="b" x2="0" y2="100%">
      <stop offset="0" stop-color="#bbb" stop-opacity=".1" />
      <stop offset="1" stop-opacity=".1" />
   </linearGradient>
   <clipPath id="a">
      <rect width="114" height="20" rx="3" fill="#fff" />
   </clipPath>
   <g clip-path="url(#a)">
      <path fill="#555" d="M0 0h59v20H0z" />
      <path fill="__COLOR__" d="M59 0h60v20H59z" />
      <path fill="url(#b)" d="M0 0h114v20H0z" />
   </g>
   <g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="110">
      <text x="305" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="490">coverage</text>
      <text x="305" y="140" transform="scale(.1)" textLength="490">coverage</text>
      <text x="860" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="450">__PERCENT__</text>
      <text x="860" y="140" transform="scale(.1)" textLength="450">__PERCENT__</text>
   </g>
</svg>
EOM

function colorForCoverage() {
  COVERAGE=$1

  # Remove decimal precision as bash can only use integers in calculations
  GOOD_FACTOR=$(echo -n "$COVERAGE" | cut -d"." -f1)
  GOOD_COLOR=(68 204 17)

  BAD_FACTOR=$(( 100 - GOOD_FACTOR ))
  BAD_COLOR=(224 93 68)

  RED=$(( BAD_COLOR[0]*BAD_FACTOR/100 + GOOD_COLOR[0]*GOOD_FACTOR/100 ))
  GREEN=$(( BAD_COLOR[1]*BAD_FACTOR/100 + GOOD_COLOR[1]*GOOD_FACTOR/100 ))
  BLUE=$(( BAD_COLOR[2]*BAD_FACTOR/100 + GOOD_COLOR[2]*GOOD_FACTOR/100 ))

  # Build SVG color string
  echo -n "rgb($RED,$GREEN,$BLUE)"
}

COLOR=$(colorForCoverage "$COVERAGE")

(echo "$TEMPLATE") \
	| sed -e "s/__PERCENT__/$COVERAGE%/g" \
	| sed -e "s/__COLOR__/'$COLOR'/g" \
	> "$OUTPUT"