Detect duplicate indices in South migrations between two git commits

detect-duplicate-south-migrations.sh

RETURN_CODE=0                                                                                                                                                                                                                                                                                                                                                              
MIGS_PATH="thefundersclub/migrations"                                                                                                                                                                                                                                                                                                                                      
                                                                                                                                                                                                                                                                                                                                                                           
# List the IDs of any migrations added since the previous commit                                                                                                                                                                                                                                                                                                           
NEW_MIGS=$(git log --name-status $GIT_PREVIOUS_COMMIT..$GIT_COMMIT -- $MIGS_PATH | egrep 'A\tthefundersclub/migrations' | cut -f 2 | xargs basename | cut -d_ -f 1)                                                                                                                                                                                                        
echo "Checking new migrations for duplication: $NEW_MIGS"                                                                                                                                                                                                                                                                                                                  
                                                                                                                                                                                                                                                                                                                                                                           
# List the last N migration IDs                                                                                                                                                                                                                                                                                                                                            
EXISTING_MIGS=$(git ls-tree -r $GIT_PREVIOUS_COMMIT | grep $MIGS_PATH | cut -d" " -f 3 | cut -f 2 | xargs basename | cut -d_ -f 1 | sort | tail -n 20)                                                                                                                                                                                                                     
echo "Existing migs: " $EXISTING_MIGS                                                                                                                                                                                                                                                                                                                                      
                                                                                                                                                                                                                                                                                                                                                                           
MERGED_MIGS=$(echo $NEW_MIGS $EXISTING_MIGS | tr -s " " "\n" | sort)                                                                                                                                                                                                                                                                                                       
echo "Merged migs: " $MERGED_MIGS                                                                                                                                                                                                                                                                                                                                          
                                                                                                                                                                                                                                                                                                                                                                           
DUPES=$(printf "$MERGED_MIGS" | uniq -d)                                                                                                                                                                                                                                                                                                                                   
if [[ $DUPES != "" ]]; then                                                                                                                                                                                                                                                                                                                                                
    echo "Found duplicate migration(s): $DUPES"                                                                                                                                                                                                                                                                                                                            
    RETURN_CODE=1                                                                                                                                                                                                                                                                                                                                                          
fi                                                                                                                                                                                                                                                                                                                                                                         
                                                                                                                                                                                                                                                                                                                                                                           
exit $RETURN_CODE