Fast failing cargo tests - runs new, recently broken and fast tests first

cargo-test-faster.sh

set -eu
touch ,logtimes
FLAGS="${FLAGS:-}"

all_tests_with_dummy_times() {
    set -x
    cargo test $FLAGS -- --list --format terse | awk '/: test/{print "0s", "new", substr($1, 1, length($1)-1)}'
}

test_times() {
    < ,logtimes jq -R 'fromjson? | select( .type == "test" ) | select( .event == ("ok", "failed") ) | .exec_time + " " + .event + " " + .name' | tr -d '"'
}   

tests_with_last_runtime() {
    { all_tests_with_dummy_times ; test_times ; } | tac | awk '!x[$3]++'
}   

ordered_tests() {
    if test -e ,logtimes ;
    then tests_with_last_runtime | sort -n | sort -sd -k2,2 | awk '{print $3}'
    else : We make use of the fact that xargs will run all tests if nothing is returned.  We may change this though.
         : We will however make sure that the code compiles:
         set -x
         cargo test $FLAGS --no-run
    fi   
}   

run_tests() {
    : It would be nice if cargo could emit both json, for the log, and human readable output.  Unfortunately not,
    : so we will have to prettify the JSON output and try to make it accessible to the human eye...
    xargs -n1 -P $(cat /proc/cpuinfo  | grep -c processor) cargo test $FLAGS -- --report-time -Z unstable-options --format json 2>/dev/null
}

format_output() {
   jq --unbuffered -R 'fromjson? | select( .type == "test" ) | select( .event == ("ok", "failed") ) | .exec_time + " " + .event + " " + .name + ( if .event == "ok" then "" else " <=======================" end )' | tr -d '"'
}

ordered_tests | grep ${@:-.} | run_tests | tee -a ,logtimes | format_output