feat(skip-exist): add _SKIPFILE template, file check

Author: WillForan

skip-exist

@@ -2,8 +2,10 @@
 set -euo pipefail
 #
 # 20260226WF - init
-# 
+#
 # TODO: add 'verb' or 'warn' instead of echo >&2
+#       or some way to suppress SKIP and already have messsages
+#
 
 REDO=${REDO:-0} # default: skip if exists. REDO !=0 means overwrite
 
@@ -15,10 +17,15 @@ USAGE:
 
   $0 sub-1/mri/aseg.nii.gz recon-all -s sub-1
   $0 sub-1/mri/aseg.nii.gz dryrun recon-all -s sub-1
+  REDO=1 $0 sub-1/mri/aseg.nii.gz recon-all -s sub-1
+
+  $0 /tmp/date.txt sh -c "date > _SKIPFILE"
 
 SYNOPSIS:
   'test -s' wrapper with REDO and verbose messaging support
 
+   _SKIPFILE in cmd will be replaced by first argument
+
 ENVIRONMENT:
    REDO=1  - overwrite (redo) even if output file exists
 
@@ -34,7 +41,7 @@ NOTES:
   or a dedicated shell
 
      $0 /tmp/date.txt sh -c 'date > /tmp/date.txt'
-  
+
   But maybe '$0' is overkill for your usage. Consider:
 
      test -s /tmp/date.txt || date > \$_
@@ -53,10 +60,22 @@ outfile="${1:?need two args. first is outfile}"; shift
    usage "ERROR: no command to run if '$outfile' doesn't exist" >&2 &&
    exit 1
 
+cmd=("${@//_SKIPFILE/"$outfile"}")
 if [ -s "$outfile" ]; then
    [ "$REDO" == 0 ] &&
       echo "# SKIP: Already have '$outfile', not running '$*'; set REDO=1 to overwrite." >&2 &&
       exit 0
    echo " # Already have '$outfile' but overwritting: REDO=$REDO." >&2
 fi
-"$@"
+
+# run the thing that should make the input
+"${cmd[@]}"
+
+# check that what we did worked
+cmd_status=$?
+
+# if there is an error (cmd_status > 0), should we still warn?
+test $cmd_status -eq 0 -a -s "$outfile" ||
+   echo "# WARNING: '$outfile' DNE or is empty after '$*'" >&2
+
+exit $cmd_status

t/skip-exist.bats

@@ -1,19 +1,34 @@
 setup(){
-  writedate() { date +%S%N > "$1"; }
+  writedate() { date +%N > "$1"; }
   export -f writedate
 }
 
 test_skipexist() { # @test
    local output
    o=$BATS_TEST_TMPDIR/d
    run skip-exist "$o" writedate "$o"
+   [[ ! $output =~ WARNING ]]
    test -s "$o"
    dt=$(cat "$o")
    run skip-exist "$o" writedate "$o"
    [[ $output =~ SKIP ]]
    [[ $(cat "$o") == "$dt" ]]
 }
 
+test_skipexist_help() { # @test
+   local output status
+   o=$BATS_TEST_TMPDIR/d
+   run skip-exist
+   [ ! -r "$o" ]
+   [ "$status" -eq 0 ]
+   [[ "$output" =~ USAGE ]]
+
+   run skip-exist "$o"
+   [ "$status" -gt 0 ]
+   [ ! -r "$o" ]
+   [[ "$output" =~ ERROR ]]
+}
+
 test_skipexist_redo() { # @test
    export REDO=1
    o=$BATS_TEST_TMPDIR/d
@@ -24,3 +39,35 @@ test_skipexist_redo() { # @test
    [[ "$output" =~ "overwrit" ]]
    [[ $(cat "$o") -gt "$dt" ]]
 }
+
+test_skipexist_nodata() { # @test
+   o=$BATS_TEST_TMPDIR/d
+   run skip-exist "$o" :
+   ! test -s "$o"
+   [[ $output =~ WARN ]]
+
+   # CHECK HERE:
+   # maybe we *do* want to warn even if command fails?
+   badfunc() { return 1; }
+   export -f badfunc
+   run skip-exist "$o" badfunc
+   [[ ! $output =~ WARN ]]
+}
+
+test_skipexist_space() { # @test
+   o=$BATS_TEST_TMPDIR/"a b"
+   run skip-exist "$o" writedate "$o"
+   test -s "$o"
+   dt=$(cat "$o")
+   run skip-exist "$o" writedate "$o"
+   [[ $(cat "$o") == "$dt" ]]
+}
+
+test_skipexist_SKIPFILE() { # @test
+   o=$BATS_TEST_TMPDIR/"a b"
+   run skip-exist "$o" writedate _SKIPFILE
+   test -s "$o"
+   dt=$(cat "$o")
+   run skip-exist "$o" writedate "$o"
+   [[ $(cat "$o") == "$dt" ]]
+}