TESTALL

#!/bin/bash
# a simple regression test framework for my bash advent-of-code solutions
USAGE='TESTALL [-v] [-t] [scripts...]
Runs the test on a solution (script name or number), or on all tests if no
argument.
To define a test, in a script put comments like:
  #TEST: input-name expected-value
This program will then run the script for each #TEST: line, with
script.input-name as argument, expecting expected-value (a number) as the last
line of output (so the script can print extra info before)
Nothing is printed in case of success, unless -v is used.
Lines starting with #TEST: but not in the proper syntax are ignored, e.g. with
a missing or non-numeric value.
Comments can be added at the end of line, like:
  #TEST: mini 17 # the simplest value, runs with dNN.mini
  #TEST: huge 51275276 # stress test with dNN.huge
E.g:
in a file d06-2.sh, the line "#TEST: input 365131" means that calling
"./TEST d06-2.sh" (or "./TEST 6") will run "d06-2.sh d06.input" and expect
that the last line of output will be 365131
Note: adding a comment #TEST_EXCLUDED: prevents the script to be run with ALL

Options:
  -v    verbose, prints what tests are being done after it
  -t    times, print the time taken by each test
'

#TEST_EXCLUDED:

nl=$'\n'
shopt -s nullglob
verbose=false
export timer=false
V(){ "$verbose" && echo "$*";}
export TIMEFORMAT='       Time: %3R s'

# runs all the tests of a script. Returns the number of failed tests
runtest(){
    local script="$1"
    grep -q '^[[:space:]]*#TEST_EXCLUDED:' "$script" && return 0
    local name value result fails=0 radix="$script"
    [[ $script =~ ^(d[0-9]+).*-[0-9](.*)[.]sh$ ]] && radix="${BASH_REMATCH[1]}"
    V "Running tests in $script"
    while read -r name value; do
        V "  TEST $radix.$name"
        if "$timer"; then
            "$verbose" || export TIMEFORMAT="  Time: %3R s for $script $radix.$name"
            result=$(time ./"$script" "$radix.$name" | tail -1)
        else
            result=$(./"$script" "$radix.$name" | tail -1)
        fi
        if [[ $result != "$value" ]]; then
            echo "***TEST ERROR: $script $radix.$name: found \"$result\", expecting \"$value\""
            (( fails++ ))
        else
            V "       OK"
        fi
    done < <(grep -oP '^[[:space:]]*#TEST:[[:space:]]*\K[-_[:alnum:]]+[[:space:]]+[[:digit:]]+' "$script")
    return "$fails"
}        

errors=0
default=ALL; for arg in "$@"; do [[ $arg =~ ^- ]] || { default=; break;}; done
for arg in "$@" $default; do
    if [[ $arg == '-v' ]]; then
        verbose=true
    elif [[ $arg == '-t' ]]; then
        timer=true
    elif [[ $arg == '-tv' ]] || [[ $arg == '-vt' ]]; then
        timer=true; verbose=true
    elif [[ $arg =~ ^- ]]; then   # any option ==> usage
        echo "USAGE: $USAGE"; exit 1
    elif [[ $arg == ALL ]]; then # run all tests found in d*.sh files
        # shellcheck disable=SC2013
        for script in $(grep -l '^[[:space:]]*#TEST:' d*.sh); do
            runtest "$script"
            (( errors += $? ))
        done
    elif [[ $arg =~ ^[[:digit:]]+$ ]]; then # run all the tests of the day
        [[ $arg =~ ^[[:digit:]]$ ]] && n="0$arg" || n="$arg"
        # shellcheck disable=SC2231
        for script in d${n}-*.sh; do
            runtest "$script"
            (( errors += $? ))
        done
        
    elif [[ -e $arg ]]; then    # run tests for a single script
        runtest "$arg"
        (( errors += $? ))
    else
        echo "***ERROR: Script not found: $arg.${nl}${nl}USAGE=$USAGE"
        exit 1
    fi
done

[[ $errors != 0 ]] && echo "$errors Tests failed!"
exit "$errors"