Add ShellCheck (#6407)

Co-authored-by: IvanCraft623 <[email protected]>

.github/workflows/main.yml

@@ -37,3 +37,15 @@ jobs:
 
       - name: Run PHP-CS-Fixer
         run: php-cs-fixer fix --dry-run --diff --ansi
+
+  shellcheck:
+    name: ShellCheck
+    runs-on: ubuntu-20.04
+    strategy:
+      fail-fast: false
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Run ShellCheck
+        uses: ludeeus/[email protected]

start.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 DIR="$(cd -P "$( dirname "${BASH_SOURCE[0]}" )" && pwd)"
-cd "$DIR"
+cd "$DIR" || { echo "Couldn't change directory to $DIR"; exit 1; }
 
 while getopts "p:f:l" OPTION 2> /dev/null; do
 	case ${OPTION} in

tests/travis.sh

@@ -7,6 +7,9 @@ while getopts "t:" OPTION 2> /dev/null; do
 		t)
 			PM_WORKERS="$OPTARG"
 			;;
+		\?)
+			break
+			;;
 	esac
 done
 
@@ -19,7 +22,7 @@ rm PocketMine-MP.phar 2> /dev/null
 mkdir "$DATA_DIR"
 mkdir "$PLUGINS_DIR"
 
-cd tests/plugins/DevTools
+cd tests/plugins/DevTools || { echo "Couldn't change directory to $DIR"; exit 1; }
 php -dphar.readonly=0 ./src/ConsoleScript.php --make ./ --relative ./ --out "$PLUGINS_DIR/DevTools.phar"
 cd ../../..
 composer make-server
@@ -45,7 +48,7 @@ if [ "$result" != "" ]; then
 	echo "$result"
 	echo Some tests did not complete successfully, changing build status to failed
 	exit 1
-elif [ $(grep -c "ERROR\|CRITICAL\|EMERGENCY" "$DATA_DIR/server.log") -ne 0 ]; then
+elif [ "$(grep -c "ERROR\|CRITICAL\|EMERGENCY" "$DATA_DIR/server.log")" -ne 0 ]; then
 	echo Server log contains error messages, changing build status to failed
 	exit 1
 else