leaderboard: fix bugs

The `leaderboard-fetch.sh` exit status didn't propagate to
`leaderboard-replace.sh`, so the latter wrote error
messages into the README. Thus we're now writing error
messages to stderr, and don't use export, so that the exit
code becomes visible.

Further, the branch in `leaderboard.yml` went the wrong
way, we called `git commit` when there were no changes, so
this commit now adds the negation.

Author: fxnn

.github/workflows/leaderboard.yml

@@ -23,7 +23,7 @@ jobs:
     - name: Commit and Push changes
       run: |
         set -e
-        if git diff --no-patch --exit-code README.md; then
+        if ! git diff --no-patch --exit-code README.md; then
           git config --global user.name "${GITHUB_ACTOR}"
           git config --global user.email "${GITHUB_ACTOR}@users.noreply.github.com"
           git commit -am "README.md: update leaderboard" \

leaderboard-fetch.sh

@@ -5,8 +5,8 @@ set -o pipefail
 aoc_year=2024
 export aoc_username="fxnn"
 
-[ -z "${AOC_SESSION_COOKIE}" ] && { echo "ERROR: missing AOC_SESSION_COOKIE"; exit 1; }
-[ -z "${AOC_LEADERBOARD_ID}" ] && { echo "ERROR: missing AOC_LEADERBOARD_ID"; exit 1; }
+[ -z "${AOC_SESSION_COOKIE}" ] && { echo "ERROR: missing AOC_SESSION_COOKIE" >&2; exit 1; }
+[ -z "${AOC_LEADERBOARD_ID}" ] && { echo "ERROR: missing AOC_LEADERBOARD_ID" >&2; exit 1; }
 
 curl \
   -sS \

leaderboard-replace.sh

@@ -1,9 +1,9 @@
 #!/bin/bash
 set -e
 
-export leaderboard="$(./leaderboard-fetch.sh)"
+leaderboard="$(./leaderboard-fetch.sh)"
 
-awk \
+awk -v leaderboard="${leaderboard}" \
   '
   BEGIN {
     isLeaderboard="false" ;
@@ -22,7 +22,7 @@ awk \
   }
   isLeaderboard=="true" && isLeaderboardPrinted=="false" {
     print "" ;
-    print "> " ENVIRON["leaderboard"] ;
+    print "> " leaderboard ;
     print "" ;
     isLeaderboardPrinted="true" ;
     next ;