Use perl regex

lint.sh

@@ -6,7 +6,7 @@
 [ -z "$ERROR_MESSAGE" ] && echo "Error: ERROR_MESSAGE is null or empty" >&2 && exit 1
 
 # Match regex title with the title
-if grep -qE -- "$TITLE_REGEX" <<< "$TITLE"; then
+if grep -qP -- "$TITLE_REGEX" <<< "$TITLE"; then
   echo "Title matches regex: $TITLE_REGEX"
 else
   echo "Error: Title does not match regex: $TITLE_REGEX" >&2

tests.sh

@@ -2,12 +2,25 @@
 
 set -e
 
-TITLE="Add something" \
+if TITLE="Add something" \
 TITLE_REGEX="^Add" \
 ERROR_MESSAGE="N/A" \
-./lint.sh && echo "Pass"
+./lint.sh; then echo "Pass"; else echo "Failed" && exit 1; fi
 
-if TITLE="Add something" \
+if ! TITLE="Add something" \
 TITLE_REGEX="^[a-z]" \
 ERROR_MESSAGE="Must be lower case" \
-./lint.sh; then echo "Failed" && exit 1; else echo "Pass"; fi
+./lint.sh; then echo "Pass"; else echo "Failed" && exit 1; fi
+
+if TITLE="Fix a thing" \
+TITLE_REGEX="^(?!\\S+ing\\s)(?!\\S+ed\\s)" \
+ERROR_MESSAGE="Must be lower case" \
+./lint.sh; then echo "Pass"; else echo "Failed" && exit 1; fi
+
+if TITLE="Fix a thing" \
+TITLE_REGEX="^(?!\\S+ing\\s)(?!\\S+ed\\s)" \
+ERROR_MESSAGE="Must be lower case" \
+./lint.sh; then echo "Pass"; else echo "Failed" && exit 1; fi
+
+
+echo All tests passed