Install bc to support arithmetic operations with floating numbers

[jorgecoca]

A common case that could happen on pipelines would be to compare a certain code coverage generated with a threshold, so you can validate that there's no coverage regressions in your codebase. For example, in my case, I run a script like this:

#!/bin/bash

set -e

LCOV_PATH=$1
MINIMUM_COVERAGE=$2
FILTERED_COVERAGE_PATH='./lcov_filtered.info'

if [ ! -z "$3" ]; then
    echo "Excluding $3 from coverage..."
    lcov --remove ${LCOV_PATH} $3 -o ${FILTERED_COVERAGE_PATH}
    CODE_COVERAGE=$(lcov --list ${FILTERED_COVERAGE_PATH} | sed -n "s/.*Total:|\([^%]*\)%.*/\1/p")
else
    CODE_COVERAGE=$(lcov --list ${LCOV_PATH} | sed -n "s/.*Total:|\([^%]*\)%.*/\1/p")
fi

echo "Minumum Coverage Required: ${MINIMUM_COVERAGE}%"
echo "Current Code Coverage: ${CODE_COVERAGE}%"
if (( $(echo "$CODE_COVERAGE < $2" | bc) )); then exit 1; fi

However, this script will fail at the very last line because bc is not installed in this Docker image (for example):

tool/coverage.sh: line 30: bc: command not found

Would it be possible to install bc in the flutter image? Thanks!

[fkorotkov]

Thank you for your descriptive example! I don't have any concerns about adding it. Seems like a small tool that can be usefull. See cirruslabs/docker-images-android#29

Unfortunately, the android images are already targeting Android 11 and flutter is only about to support it so it's not freezable to update flutter image to cirrusci/android-sdk:30. Will bash magic work for you in the meantime?

if [ $CODE_COVERAGE -le $2 ]; then exit 1; fi

[jorgecoca]

The problem with that line is the -le (or that same family) only works with integers, not floating numbers, so if your coverage is, let's say, 87.5, then you won't be able to compute.

My bash knowledge is really limited, so any guidance would be appreciated: if you can think of an alternative to compare numbers (integers and floating), then let me know and I am happy to run it on my pipeline!

Thank you so much!

[fkorotkov]

Should be fixed now.