frog_emojis/.github/workflows/main.yml

name: Test SVGs

# Triggers the workflow on push / pull request events, and on manual trigger
on: [push, pull_request, workflow_dispatch]

jobs:
  Test-SVGs:
    runs-on: ubuntu-latest

    steps:
      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
      - uses: actions/checkout@v2

      - name: Check SVG validity
        run: |
          # Enables globstar to recursively go through folders
          shopt -s globstar
          errArr=()
          for f in ./svg/**/*.svg 
          do
            echo "Checking '$f'"
            
            # Checking if file contains space in path
            if [[ $f == *\ * ]] ; then
              errArr+=("$f contains a space!")
            fi
            
            # Save first few lines of file into variable to make parsing faster
            headfile=$(head -n 50 "$f")
            # Gets everything in between the viewBox quotes
            vbStr=${headfile}
            vbStr=${vbStr##*viewBox=\"}
            vbStr=${vbStr%%\"*}

            # sets x, y, width, height params
            vbArr=($vbStr)
            vbX=${vbArr[0]}
            vbY=${vbArr[1]}
            vbW=${vbArr[2]}
            vbH=${vbArr[3]}

            # Check that viewbox' x and y are 0
            if [[ $vbX != 0 || $vbY != 0 ]] ; then
              errArr+=("$f has viewBox' x: $vbX and y: $vbY")
            fi

            # Check that viewbox' width and height are equal
            if [[ $vbW != $vbH ]] ; then
              errArr+=("$f has viewbox -width: $vbW and -height: $vbH")
            fi

            # Check if normal width/height parameters exist and
            # if yes, compare them with viewBox height/width
            svgTags=${headfile}
            svgTags=${svgTags##*\<svg}
            svgTags=${svgTags%%\>*}
            
            # Width comparison
            if [[ $svgTags == *width* ]] ; then
              w=${svgTags##*width=\"}
              w=${w%%\"*}
              if [[ $w != $vbW ]] ; then
                errArr+=("$f has width: $w but viewbox-width: $vbW")
              fi
            fi

            # Height comparison
            if [[ $svgTags == *height* ]] ; then
              h=${svgTags##*height=\"}
              h=${h%%\"*}
              if [[ $h != $vbH ]] ; then
                errArr+=("$f has height: $h but viewbox-height: $vbH")
              fi
            fi
            
            # Check that svg is not 1 line
            if [[ $(wc -l < "$f") == 0 ]] ; then
              errArr+=("$f is only one line!")
            fi
          done
          
          # Results
          # If the error Array is not empty, print everything from it and error out
          # Otherwise exit normally
          if [[ ${#errArr[@]} != 0 ]] ; then
            echo "--------------------"
            for errMess in "${errArr[@]}"
            do
              echo $errMess
            done
            exit 1
          fi
          echo "No Errors!"