Add ShellCheck to pre-commit config

.pre-commit-config.yaml

@@ -55,3 +55,7 @@ repos:
         - id: black
           args:
             - --safe
+  - repo: https://github.com/koalaman/shellcheck-precommit
+    rev: v0.8.0
+    hooks:
+        - id: shellcheck

dag-sync.sh

@@ -14,16 +14,14 @@ SLACK_URL=$1
 SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
 cd "$SCRIPT_DIR"
 
-# Get current commit hash
-current=$(git rev-parse HEAD)
 # Update origin
 git fetch origin
 # Get new commit hash *one commit ahead* of this one
 new=$(git rev-list --reverse --topo-order HEAD..origin/main | head -1)
 # If there is no new commit hash to move to, nothing has changed, quit early
-[ -z $new ] && exit
+[ -z "$new" ] && exit
 # Move ahead to this new commit
-git reset --hard $new
+git reset --hard "$new"
 # Pull out the subject from the new commit
 subject=$(git log -1 --format='%s')
 
@@ -32,7 +30,7 @@ if [ -z "$SLACK_URL" ]
   then
   echo "Slack hook was not supplied! Updates will not be posted"
 else
-  curl $SLACK_URL \
+  curl "$SLACK_URL" \
     -X POST \
     -H 'Content-Type: application/json' \
     -d '{"text":"Deployed: '"$subject"'","username":"DAG Sync","icon_emoji":":recycle:","blocks":[{"type":"section","text":{"type":"mrkdwn","text":"Deployed: <https://github.com/WordPress/openverse-catalog/commit/'"$new"'|'"$subject"'>"}}]}'

docker/airflow/entrypoint.sh

@@ -41,20 +41,20 @@ header "MODIFYING ENVIRONMENT"
 # subprocess manipulation via <(...) syntax to allow the `export` calls
 # to propagate to the outer shell.
 # See: https://unix.stackexchange.com/a/402752
-while read var_string; do
+while read -r var_string; do
     # get the variable name
-    var_name=`expr "$var_string" : '^\([A-Z_]*\)'`
+    var_name=$(expr "$var_string" : '^\([A-Z_]*\)')
     echo "Variable Name: $var_name"
     # get the old value
-    old_value=`expr "$var_string" : '^[A-Z_]*=\(http.*\)$'`
+    old_value=$(expr "$var_string" : '^[A-Z_]*=\(http.*\)$')
     echo "    Old Value: $old_value"
     # call python to url encode the http clause
-    url_encoded=`python -c "from urllib.parse import quote_plus; import sys; print(quote_plus(sys.argv[1]))" $old_value`
+    url_encoded=$(python -c "from urllib.parse import quote_plus; import sys; print(quote_plus(sys.argv[1]))" "$old_value")
     # prepend https://
     new_value='https://'$url_encoded
     echo "    New Value: $new_value"
     # set the environment variable
-    export $var_name=$new_value
+    export "$var_name"="$new_value"
 # only include airflow connections with http somewhere in the string
 done < <(env | grep "^AIRFLOW_CONN[A-Z_]\+=http.*$")
 

tests/dags/providers/provider_api_scripts/resources/wikimedia/prettify.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
 
 T=$(mktemp)
-jq '.' $1 > $T
-mv $T $1
+jq '.' "$1" > "$T"
+mv "$T" "$1"